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ESSAYS:

SCIENTIFIC, POLITICAL, & SPECULATIVE.


BY

HERBERT SPENCER.


LIBRARY EDITION,

(OTHERWISE FIFTH THOUSAND)

_Containing Seven Essays not before Republished, and various other
additions._


VOL. I.


   WILLIAMS AND NORGATE,
   14, HENRIETTA STREET, COVENT GARDEN, LONDON:
   AND 20. SOUTH FREDERICK STREET. EDINBURGH.
   1891.




   LONDON:
   G. NORMAN AND SON, PRINTERS, HART STREET,
   COVENT GARDEN.




PREFACE


Excepting those which have appeared as articles in periodicals during
the last eight years, the essays here gathered together were originally
re-published in separate volumes at long intervals. The first volume
appeared in December 1857; the second in November 1863; and the third in
February 1874. By the time the original editions of the first two had
been sold, American reprints, differently entitled and having the essays
differently arranged, had been produced; and, for economy's sake, I have
since contented myself with importing successive supplies printed from
the American stereotype plates. Of the third volume, however, supplies
have, as they were required, been printed over here, from plates partly
American and partly English. The completion of this final edition of
course puts an end to this make-shift arrangement.

The essays above referred to as having been written since 1882, are now
incorporated with those previously re-published. There are seven of
them; namely--"Morals and Moral Sentiments," "The Factors of Organic
Evolution," "Professor Green's Explanations," "The Ethics of Kant,"
"Absolute Political Ethics," "From Freedom to Bondage," and "The
Americans." As well as these large additions there are small additions,
in the shape of postscripts to various essays--one to "The Constitution
of the Sun," one to "The Philosophy of Style," one to "Railway Morals,"
one to "Prison Ethics," and one to "The Origin and Function of Music:"
which last is about equal in length to the original essay. Changes have
been made in many of the essays: in some cases by omitting passages and
in other cases by including new ones. Especially the essay on "The
Nebular Hypothesis" may be named as one which, though unchanged in
essentials, has been much altered by additions and subtractions, and by
bringing its statements up to date; so that it has been in large measure
re-cast. Beyond these respects in which this final edition differs from
preceding editions, it differs in having undergone a verification of its
references and quotations, as well as a second verbal revision.

Naturally the fusion of three separate series of essays into one series,
has made needful a general re-arrangement. Whether to follow the order
of time or the order of subjects was a question which presented itself;
and, as neither alternative promised satisfactory results, I eventually
decided to compromise--to follow partly the one order and partly the
other. The first volume is made up of essays in which the idea of
evolution, general or special, is dominant. In the second volume essays
dealing with philosophical questions, with abstract and concrete
science, and with aesthetics, are brought together; but though all of
them are tacitly evolutionary, their evolutionism is an incidental
rather than a necessary trait. The ethical, political, and social essays
composing the third volume, though mostly written from the evolution
point of view, have for their more immediate purposes the enunciation of
doctrines which are directly practical in their bearings. Meanwhile,
within each volume the essays are arranged in order of time: not indeed
strictly, but so far as consists with the requirements of sub-classing.

Beyond the essays included in these three volumes, there remain several
which I have not thought it well to include--in some cases because of
their personal character, in other cases because of their relative
unimportance, and in yet other cases because they would scarcely be
understood in the absence of the arguments to which they are replies.
But for the convenience of any who may wish to find them, I append their
titles and places of publication. These are as follows:--"Retrogressive
Religion," in _The Nineteenth Century_ for July 1884; "Last Words about
Agnosticism and the Religion of Humanity," in _The Nineteenth Century_
for November 1884; a note to Prof. Cairns' Critique on the _Study of
Sociology_, in _The Fortnightly Review_, for February 1875; "A Short
Rejoinder" [to Mr. J. F. McLennan], _Fortnightly Review_, June 1877;
"Prof. Goldwin Smith as a Critic," _Contemporary Review_, March 1882; "A
Rejoinder to M. de Laveleye," _Contemporary Review_, April 1885.

LONDON, _December, 1890_.




CONTENTS OF VOL. I.


                                                                    PAGE

   THE DEVELOPMENT HYPOTHESIS                                          1

   PROGRESS: ITS LAW AND CAUSE                                         8

   TRANSCENDENTAL PHYSIOLOGY                                          63

   THE NEBULAR HYPOTHESIS                                            108

   ILLOGICAL GEOLOGY                                                 192

   BAIN ON THE EMOTIONS AND THE WILL                                 241

   THE SOCIAL ORGANISM                                               265

   THE ORIGIN OF ANIMAL WORSHIP                                      308

   MORALS AND MORAL SENTIMENTS                                       331

   THE COMPARATIVE PSYCHOLOGY OF MAN                                 351

   MR. MARTINEAU ON EVOLUTION                                        371

   THE FACTORS OF ORGANIC EVOLUTION                                  389


   (_For Index, see Volume III._)




THE DEVELOPMENT HYPOTHESIS.

    [_Originally published in _The Leader, _for March 20,_ 1852. _Brief
    though it is, I place this essay before the rest, partly because
    with the exception of a similarly-brief essay on "Use and Beauty",
    it came first in order of time, but chiefly because it came first in
    order of thought, and struck the keynote of all that was to
    follow._]


In a debate upon the development hypothesis, lately narrated to me by a
friend, one of the disputants was described as arguing that as, in all
our experience, we know no such phenomenon as transmutation of species,
it is unphilosophical to assume that transmutation of species ever takes
place. Had I been present I think that, passing over his assertion,
which is open to criticism, I should have replied that, as in all our
experience we have never known a species _created_, it was, by his own
showing, unphilosophical to assume that any species ever had been
created.

Those who cavalierly reject the Theory of Evolution as not being
adequately supported by facts, seem to forget that their own theory is
supported by no facts at all. Like the majority of men who are born to a
given belief, they demand the most rigorous proof of any adverse belief,
but assume that their own needs none. Here we find, scattered over the
globe, vegetable and animal organisms numbering, of the one kind
(according to Humboldt), some 320,000 species, and of the other, some
2,000,000 species (see Carpenter); and if to these we add the numbers of
animal and vegetable species which have become extinct, we may safely
estimate the number of species that have existed, and are existing, on
the Earth, at not less than _ten millions_. Well, which is the most
rational theory about these ten millions of species? Is it most likely
that there have been ten millions of special creations? or is it most
likely that, by continual modifications due to change of circumstances,
ten millions of varieties have been produced, as varieties are being
produced still?

Doubtless many will reply that they can more easily conceive ten
millions of special creations to have taken place, than they can
conceive that ten millions of varieties have arisen by successive
modifications. All such, however, will find, on inquiry, that they are
under an illusion. This is one of the many cases in which men do not
really believe, but rather _believe they believe_. It is not that they
can truly conceive ten millions of special creations to have taken
place, but that they _think they can do so_. Careful introspection will
show them that they have never yet realized to themselves the creation
of even _one_ species. If they have formed a definite conception of the
process, let them tell us how a new species is constructed, and how it
makes its appearance. Is it thrown down from the clouds? or must we hold
to the notion that it struggles up out of the ground? Do its limbs and
viscera rush together from all the points of the compass? or must we
receive the old Hebrew idea, that God takes clay and moulds a new
creature? If they say that a new creature is produced in none of these
modes, which are too absurd to be believed, then they are required to
describe the mode in which a new creature _may_ be produced--a mode
which does _not_ seem absurd; and such a mode they will find that they
neither have conceived nor can conceive.

Should the believers in special creations consider it unfair thus to
call upon them to describe how special creations take place, I reply
that this is far less than they demand from the supporters of the
Development Hypothesis. They are merely asked to point out a
_conceivable_ mode. On the other hand, they ask, not simply for a
_conceivable_ mode, but for the _actual_ mode. They do not say--Show us
how this _may_ take place; but they say--Show us how this _does_ take
place. So far from its being unreasonable to put the above question, it
would be reasonable to ask not only for a _possible_ mode of special
creation, but for an _ascertained_ mode; seeing that this is no greater
a demand than they make upon their opponents.

And here we may perceive how much more defensible the new doctrine is
than the old one. Even could the supporters of the Development
Hypothesis merely show that the origination of species by the process of
modification is conceivable, they would be in a better position than
their opponents. But they can do much more than this. They can show that
the process of modification has effected, and is effecting, decided
changes in all organisms subject to modifying influences. Though, from
the impossibility of getting at a sufficiency of facts, they are unable
to trace the many phases through which any existing species has passed
in arriving at its present form, or to identify the influences which
caused the successive modifications; yet, they can show that any
existing species--animal or vegetable--when placed under conditions
different from its previous ones, _immediately begins to undergo certain
changes fitting it for the new conditions_. They can show that in
successive generations these changes continue; until, ultimately, the
new conditions become the natural ones. They can show that in cultivated
plants, in domesticated animals, and in the several races of men, such
alterations have taken place. They can show that the degrees of
difference so produced are often, as in dogs, greater than those on
which distinctions of species are in other cases founded. They can show
that it is a matter of dispute whether some of these modified forms are
varieties or separate species. They can show, too, that the changes
daily taking place in ourselves--the facility that attends long
practice, and the loss of aptitude that begins when practice ceases--the
strengthening of passions habitually gratified, and the weakening of
those habitually curbed--the development of every faculty, bodily,
moral, or intellectual, according to the use made of it--are all
explicable on this same principle. And thus they can show that
throughout all organic nature there _is_ at work a modifying influence
of the kind they assign as the cause of these specific differences: an
influence which, though slow in its action, does, in time, if the
circumstances demand it, produce marked changes--an influence which, to
all appearance, would produce in the millions of years, and under the
great varieties of condition which geological records imply, any amount
of change.

Which, then, is the most rational hypothesis?--that of special creations
which has neither a fact to support it nor is even definitely
conceivable; or that of modification, which is not only definitely
conceivable, but is countenanced by the habitudes of every existing
organism?

That by any series of changes a protozoon should ever become a mammal,
seems to those who are not familiar with zoology, and who have not seen
how clear becomes the relationship between the simplest and the most
complex forms when intermediate forms are examined, a very grotesque
notion. Habitually looking at things rather in their statical aspect
than in their dynamical aspect, they never realize the fact that, by
small increments of modification, any amount of modification may in time
be generated. That surprise which they feel on finding one whom they
last saw as a boy, grown into a man, becomes incredulity when the degree
of change is greater. Nevertheless, abundant instances are at hand of
the mode in which we may pass to the most diverse forms by insensible
gradations. Arguing the matter some time since with a learned professor,
I illustrated my position thus:--You admit that there is no apparent
relationship between a circle and an hyperbola. The one is a finite
curve; the other is an infinite one. All parts of the one are alike; of
the other no parts are alike [save parts on its opposite sides]. The one
incloses a space; the other will not inclose a space though produced for
ever. Yet opposite as are these curves in all their properties, they may
be connected together by a series of intermediate curves, no one of
which differs from the adjacent ones in any appreciable degree. Thus, if
a cone be cut by a plane at right angles to its axis we get a circle.
If, instead of being perfectly at right angles, the plane subtends with
the axis an angle of 89° 59´, we have an ellipse which no human eye,
even when aided by an accurate pair of compasses, can distinguish from a
circle. Decreasing the angle minute by minute, the ellipse becomes first
perceptibly eccentric, then manifestly so, and by and by acquires so
immensely elongated a form, as to bear no recognizable resemblance to a
circle. By continuing this process, the ellipse passes insensibly into a
parabola; and, ultimately, by still further diminishing the angle, into
an hyperbola. Now here we have four different species of curve--circle,
ellipse, parabola, and hyperbola--each having its peculiar properties
and its separate equation, and the first and last of which are quite
opposite in nature, connected together as members of one series, all
producible by a single process of insensible modification.

But the blindness of those who think it absurd to suppose that complex
organic forms may have arisen by successive modifications out of simple
ones, becomes astonishing when we remember that complex organic forms
are daily being thus produced. A tree differs from a seed immeasurably
in every respect--in bulk, in structure, in colour, in form, in chemical
composition: differs so greatly that no visible resemblance of any kind
can be pointed out between them. Yet is the one changed in the course of
a few years into the other: changed so gradually, that at no moment can
it be said--Now the seed ceases to be, and the tree exists. What can be
more widely contrasted than a newly-born child and the small,
semi-transparent spherule constituting the human ovum? The infant is so
complex in structure that a cyclopædia is needed to describe its
constituent parts. The germinal vesicle is so simple that it may be
defined in a line. Nevertheless a few months suffice to develop the one
out of the other; and that, too, by a series of modifications so small,
that were the embryo examined at successive minutes, even a microscope
would with difficulty disclose any sensible changes. That the uneducated
and the ill-educated should think the hypothesis that all races of
beings, man inclusive, may in process of time have been evolved from the
simplest monad, a ludicrous one, is not to be wondered at. But for the
physiologist, who knows that every individual being _is_ so evolved--who
knows, further, that in their earliest condition the germs of all plants
and animals whatever are so similar, "that there is no appreciable
distinction amongst them, which would enable it to be determined whether
a particular molecule is the germ of a Conferva or of an Oak, of a
Zoophyte or of a Man;"[1]--for him to make a difficulty of the matter is
inexcusable. Surely if a single cell may, when subjected to certain
influences, become a man in the space of twenty years; there is nothing
absurd in the hypothesis that under certain other influences, a cell
may, in the course of millions of years, give origin to the human race.

We have, indeed, in the part taken by many scientific men in this
controversy of "Law _versus_ Miracle," a good illustration of the
tenacious vitality of superstitions. Ask one of our leading geologists
or physiologists whether he believes in the Mosaic account of the
creation, and he will take the question as next to an insult. Either he
rejects the narrative entirely, or understands it in some vague
nonnatural sense. Yet one part of it he unconsciously adopts; and that,
too, literally. For whence has he got this notion of "special
creations," which he thinks so reasonable, and fights for so vigorously?
Evidently he can trace it back to no other source than this myth which
he repudiates. He has not a single fact in nature to cite in proof of
it; nor is he prepared with any chain of reasoning by which it may be
established. Catechize him, and he will be forced to confess that the
notion was put into his mind in childhood as part of a story which he
now thinks absurd. And why, after rejecting all the rest of the story,
he should strenuously defend this last remnant of it, as though he had
received it on valid authority, he would be puzzled to say.

FOOTNOTE:

[Footnote 1: Carpenter, _Principles of Comparative Physiology_, p. 474.]




PROGRESS: ITS LAW AND CAUSE.

    [_First published in_ The Westminster Review _for April,_ 1857.
    _Though the ideas and illustrations contained in this essay were
    eventually incorporated in_ First Principles, _yet I think it well
    here to reproduce it as exhibiting the form under which the General
    Doctrine of Evolution made its first appearance._]


The current conception of progress is shifting and indefinite. Sometimes
it comprehends little more than simple growth--as of a nation in the
number of its members and the extent of territory over which it spreads.
Sometimes it has reference to quantity of material products--as when the
advance of agriculture and manufactures is the topic. Sometimes the
superior quality of these products is contemplated; and sometimes the
new or improved appliances by which they are produced. When, again, we
speak of moral or intellectual progress, we refer to states of the
individual or people exhibiting it; while, when the progress of Science,
or Art, is commented upon, we have in view certain abstract results of
human thought and action. Not only, however, is the current conception
of progress more or less vague, but it is in great measure erroneous. It
takes in not so much the reality of progress as its accompaniments--not
so much the substance as the shadow. That progress in intelligence seen
during the growth of the child into the man, or the savage into the
philosopher, is commonly regarded as consisting in the greater number
of facts known and laws understood; whereas the actual progress consists
in those internal modifications of which this larger knowledge is the
expression. Social progress is supposed to consist in the making of a
greater quantity and variety of the articles required for satisfying
men's wants; in the increasing security of person and property; in
widening freedom of action; whereas, rightly understood, social progress
consists in those changes of structure in the social organism which have
entailed these consequences. The current conception is a teleological
one. The phenomena are contemplated solely as bearing on human
happiness. Only those changes are held to constitute progress which
directly or indirectly tend to heighten human happiness; and they are
thought to constitute progress simply _because_ they tend to heighten
human happiness. But rightly to understand progress, we must learn the
nature of these changes, considered apart from our interests. Ceasing,
for example, to regard the successive geological modifications that have
taken place in the Earth, as modifications that have gradually fitted it
for the habitation of Man, and as _therefore_ constituting geological
progress, we must ascertain the character common to these
modifications--the law to which they all conform. And similarly in every
other case. Leaving out of sight concomitants and beneficial
consequences, let us ask what progress is in itself.

In respect to that progress which individual organisms display in the
course of their evolution, this question has been answered by the
Germans. The investigations of Wolff, Goethe, and von Baer, have
established the truth that the series of changes gone through during the
development of a seed into a tree, or an ovum into an animal, constitute
an advance from homogeneity of structure to heterogeneity of structure.
In its primary stage, every germ consists of a substance that is uniform
throughout, both in texture and chemical composition. The first step is
the appearance of a difference between two parts of this substance; or,
as the phenomenon is called in physiological language, a
differentiation. Each of these differentiated divisions presently begins
itself to exhibit some contrast of parts: and by and by these secondary
differentiations become as definite as the original one. This process is
continuously repeated--is simultaneously going on in all parts of the
growing embryo; and by endless such differentiations there is finally
produced that complex combination of tissues and organs constituting the
adult animal or plant. This is the history of all organisms whatever. It
is settled beyond dispute that organic progress consists in a change
from the homogeneous to the heterogeneous.

Now, we propose in the first place to show, that this law of organic
progress is the law of all progress. Whether it be in the development of
the Earth, in the development of Life upon its surface, in the
development of Society, of Government, of Manufactures, of Commerce, of
Language, Literature, Science, Art, this same evolution of the simple
into the complex, through successive differentiations, holds throughout.
From the earliest traceable cosmical changes down to the latest results
of civilization, we shall find that the transformation of the
homogeneous into the heterogeneous, is that in which progress
essentially consists.

With the view of showing that _if_ the Nebular Hypothesis be true, the
genesis of the solar system supplies one illustration of this law, let
us assume that the matter of which the sun and planets consist was once
in a diffused form; and that from the gravitation of its atoms there
resulted a gradual concentration. By the hypothesis, the solar system in
its nascent state existed as an indefinitely extended and nearly
homogeneous medium--a medium almost homogeneous in density, in
temperature, and in other physical attributes. The first change in the
direction of increased aggregation, brought a contrast in density and a
contrast in temperature, between the interior and the exterior of this
mass. Simultaneously the drawing in of outer parts caused motions ending
in rotation round a centre with various angular velocities. These
differentiations increased in number and degree until there was evolved
the organized group of sun, planets, and satellites, which we now
know--a group which presents numerous contrasts of structure and action
among its members. There are the immense contrasts between the sun and
the planets, in bulk and in weight; as well as the subordinate contrasts
between one planet and another, and between the planets and their
satellites. There is the similarly-marked contrast between the sun as
almost stationary (relatively to the other members of the Solar System),
and the planets as moving round him with great velocity: while there are
the secondary contrasts between the velocities and periods of the
several planets, and between their simple revolutions and the double
ones of their satellites, which have to move round their primaries while
moving round the sun. There is the yet further strong contrast between
the sun and the planets in respect of temperature; and there is good
reason to suppose that the planets and satellites differ from each other
in their proper heats, as well as in the amounts of heat they receive
from the sun. When we bear in mind that, in addition to these various
contrasts, the planets and satellites also differ in respect to their
distances from each other and their primary; in respect to the
inclinations of their orbits, the inclinations of their axes, their
times of rotation on their axes, their specific gravities, and their
physical constitutions; we see what a high degree of heterogeneity the
solar system exhibits, when compared with the almost complete
homogeneity of the nebulous mass out of which it is supposed to have
originated.

Passing from this hypothetical illustration, which must be taken for
what it is worth, without prejudice to the general argument, let us
descend to a more certain order of evidence. It is now generally agreed
among geologists and physicists that the Earth was at one time a mass
of molten matter. If so, it was at that time relatively homogeneous in
consistence, and, in virtue of the circulation which takes place in
heated fluids, must have been comparatively homogeneous in temperature;
and it must have been surrounded by an atmosphere consisting partly of
the elements of air and water, and partly of those various other
elements which are among the more ready to assume gaseous forms at high
temperatures. That slow cooling by radiation which is still going on at
an inappreciable rate, and which, though originally far more rapid than
now, necessarily required an immense time to produce any decided change,
must ultimately have resulted in the solidification of the portion most
able to part with its heat--namely, the surface. In the thin crust thus
formed we have the first marked differentiation. A still further
cooling, a consequent thickening of this crust, and an accompanying
deposition of all solidifiable elements contained in the atmosphere,
must finally have been followed by the condensation of the water
previously existing as vapour. A second marked differentiation must thus
have arisen; and as the condensation must have taken place on the
coolest parts of the surface--namely, about the poles--there must thus
have resulted the first geographical distinction of parts. To these
illustrations of growing heterogeneity, which, though deduced from known
physical laws, may be regarded as more or less hypothetical, Geology
adds an extensive series that have been inductively established.
Investigations show that the Earth has been continually becoming more
heterogeneous in virtue of the multiplication of sedimentary strata
which form its crust; also, that it has been becoming more heterogeneous
in respect of the composition of these strata, the later of which, being
made from the detritus of the earlier, are many of them rendered highly
complex by the mixture of materials they contain; and further, that this
heterogeneity has been vastly increased by the actions of the Earth's
still molten nucleus upon its envelope, whence have resulted not only
many kinds of igneous rocks, but the tilting up of sedimentary strata at
all angles, the formation of faults and metallic veins, the production
of endless dislocations and irregularities. Yet again, geologists teach
us that the Earth's surface has been growing more varied in
elevation--that the most ancient mountain systems are the smallest, and
the Andes and Himalayas the most modern; while in all probability there
have been corresponding changes in the bed of the ocean. As a
consequence of these ceaseless differentiations, we now find that no
considerable portion of the Earth's exposed surface is like any other
portion, either in contour, in geologic structure, or in chemical
composition; and that in most parts it changes from mile to mile in all
these characters. Moreover, there has been simultaneously going on a
differentiation of climates. As fast as the Earth cooled and its crust
solidified, there arose appreciable differences in temperature between
those parts of its surface more exposed to the sun and those less
exposed. As the cooling progressed, these differences became more
pronounced; until there finally resulted those marked contrasts between
regions of perpetual ice and snow, regions where winter and summer
alternately reign for periods varying according to the latitude, and
regions where summer follows summer with scarcely an appreciable
variation. At the same time the many and varied elevations and
subsidences of portions of the Earth's crust, bringing about the present
irregular distribution of land and sea, have entailed modifications of
climate beyond those dependent on latitude; while a yet further series
of such modifications have been produced by increasing differences of
elevation in the land, which have in sundry places brought arctic,
temperate, and tropical climates to within a few miles of one another.
And the general outcome of these changes is, that not only has every
extensive region its own meteorologic conditions, but that every
locality in each region differs more or less from others in those
conditions; as in its structure, its contour, its soil. Thus, between
our existing Earth, the phenomena of whose crust neither geographers,
geologists, mineralogists, nor meteorologists have yet enumerated, and
the molten globe out of which it was evolved, the contrast in
heterogeneity is extreme.

When from the Earth itself we turn to the plants and animals which have
lived, or still live, upon its surface, we find ourselves in some
difficulty from lack of facts. That every existing organism has been
developed out of the simple into the complex, is indeed the first
established truth of all; and that every organism which existed in past
times was similarly developed, is an inference no physiologist will
hesitate to draw. But when we pass from individual forms of life to Life
in general, and inquire whether the same law is seen in the _ensemble_
of its manifestations,--whether modern plants and animals are of more
heterogeneous structure than ancient ones, and whether the Earth's
present Flora and Fauna are more heterogeneous than the Flora and Fauna
of the past,--we find the evidence so fragmentary, that every conclusion
is open to dispute. Three-fifths of the Earth's surface being covered by
water; a great part of the exposed land being inaccessible to, or
untravelled by, the geologist; the greater part of the remainder having
been scarcely more than glanced at; and even the most familiar portions,
as England, having been so imperfectly explored that a new series of
strata has been added within these four years,--it is impossible for us
to say with certainty what creatures have, and what have not, existed at
any particular period. Considering the perishable nature of many of the
lower organic forms, the metamorphosis of numerous sedimentary strata,
and the great gaps occurring among the rest, we shall see further reason
for distrusting our deductions. On the one hand, the repeated discovery
of vertebrate remains in strata previously supposed to contain none,--of
reptiles where only fish were thought to exist,--of mammals where it was
believed there were no creatures higher than reptiles,--renders it daily
more manifest how small is the value of negative evidence. On the other
hand, the worthlessness of the assumption that we have discovered the
earliest, or anything like the earliest, organic remains, is becoming
equally clear. That the oldest known sedimentary rocks have been greatly
changed by igneous action, and that still older ones have been totally
transformed by it, is becoming undeniable. And the fact that sedimentary
strata earlier than any we know, have been melted up, being admitted, it
must also be admitted that we cannot say how far back in time this
destruction of sedimentary strata has been going on. Thus the title
_Palæozoic_, as applied to the earliest known fossiliferous strata,
involves a _petitio principii_; and, for aught we know to the contrary,
only the last few chapters of the Earth's biological history may have
come down to us. On neither side, therefore, is the evidence conclusive.
Nevertheless we cannot but think that, scanty as they are, the facts,
taken altogether, tend to show both that the more heterogeneous
organisms have been evolved in the later geologic periods, and that Life
in general has been more heterogeneously manifested as time has
advanced. Let us cite, in illustration, the one case of the
_Vertebrata_. The earliest known vertebrate remains are those of Fishes;
and Fishes are the most homogeneous of the vertebrata. Later and more
heterogeneous are Reptiles. Later still, and more heterogeneous still,
are Birds and Mammals. If it be said that the Palæozoic deposits, not
being estuary deposits, are not likely to contain the remains of
terrestrial vertebrata, which may nevertheless have existed at that era,
we reply that we are merely pointing to the leading facts, _such as they
are_. But to avoid any such criticism, let us take the mammalian
subdivision only. The earliest known remains of mammals are those of
small marsupials, which are the lowest of the mammalian type; while,
conversely, the highest of the mammalian type--Man--is the most recent.
The evidence that the vertebrate fauna, as a whole, has become more
heterogeneous, is considerably stronger. To the argument that the
vertebrate fauna of the Palæozoic period, consisting, so far as we know,
entirely of Fishes, was less heterogeneous than the modern vertebrate
fauna, which includes Reptiles, Birds, and Mammals, of multitudinous
genera, it may be replied, as before, that estuary deposits of the
Palæozoic period, could we find them, might contain other orders of
vertebrata. But no such reply can be made to the argument that whereas
the marine vertebrata of the Palæozoic period consisted entirely of
cartilaginous fishes, the marine vertebrata of later periods include
numerous genera of osseous fishes; and that, therefore, the later marine
vertebrate faunas are more heterogeneous than the oldest known one. Nor,
again, can any such reply be made to the fact that there are far more
numerous orders and genera of mammalian remains in the tertiary
formations than in the secondary formations. Did we wish merely to make
out the best case, we might dwell upon the opinion of Dr. Carpenter, who
says that "the general facts of Palæontology appear to sanction the
belief, that _the same plan_ may be traced out in what may be called
_the general life of the globe_, as in _the individual life_ of every
one of the forms of organized being which now people it." Or we might
quote, as decisive, the judgment of Professor Owen, who holds that the
earlier examples of each group of creatures severally departed less
widely from archetypal generality than the later examples--were
severally less unlike the fundamental form common to the group as a
whole; and thus constituted a less heterogeneous group of creatures. But
in deference to an authority for whom we have the highest respect, who
considers that the evidence at present obtained does not justify a
verdict either way, we are content to leave the question open.[2]

Whether an advance from the homogeneous to the heterogeneous is or is
not displayed in the biological history of the globe, it is clearly
enough displayed in the progress of the latest and most heterogeneous
creature--Man. It is true alike that, during the period in which the
Earth has been peopled, the human organism has grown more heterogeneous
among the civilized divisions of the species; and that the species, as a
whole, has been growing more heterogeneous in virtue of the
multiplication of races and the differentiation of these races from each
other. In proof of the first of these positions, we may cite the fact
that, in the relative development of the limbs, the civilized man
departs more widely from the general type of the placental mammalia than
do the lower human races. While often possessing well-developed body and
arms, the Australian has very small legs: thus reminding us of the
chimpanzee and the gorilla, which present no great contrasts in size
between the hind and fore limbs. But in the European, the greater length
and massiveness of the legs have become marked--the fore and hind limbs
are more heterogeneous. Again, the greater ratio which the cranial bones
bear to the facial bones illustrates the same truth. Among the
vertebrata in general, progress is marked by an increasing heterogeneity
in the vertebral column, and more especially in the segments
constituting the skull: the higher forms being distinguished by the
relatively larger size of the bones which cover the brain, and the
relatively  smaller size of those which form the jaws, &c. Now this
characteristic, which is stronger in Man than in any other creature, is
stronger in the European than in the savage. Moreover, judging from the
greater extent and variety of faculty he exhibits, we may infer that the
civilized man has also a more complex or heterogeneous nervous system
than the uncivilized man: and, indeed, the fact is in part visible in
the increased ratio which his cerebrum bears to the subjacent ganglia,
as well as in the wider departure from symmetry in its convolutions. If
further elucidation be needed, we may find it in every nursery. The
infant European has sundry marked points of resemblance to the lower
human races; as in the flatness of the alæ of the nose, the depression
of its bridge, the divergence and forward opening of the nostrils, the
form of the lips, the absence of a frontal sinus, the width between the
eyes, the smallness of the legs. Now, as the developmental process by
which these traits are turned into those of the adult European, is a
continuation of that change from the homogeneous to the heterogeneous
displayed during the previous evolution of the embryo, which every
anatomist will admit; it follows that the parallel developmental process
by which the like traits of the barbarous races have been turned into
those of the civilized races, has also been a continuation of the change
from the homogeneous to the heterogeneous. The truth of the second
position--that Mankind, as a whole, have become more heterogeneous--is
so obvious as scarcely to need illustration. Every work on Ethnology, by
its divisions and subdivisions of races, bears testimony to it. Even
were we to admit the hypothesis that Mankind originated from several
separate stocks, it would still remain true, that as, from each of these
stocks, there have sprung many now widely-different tribes, which are
proved by philological evidence to have had a common origin, the race as
a whole is far less homogeneous than it once was. Add to which, that we
have, in the Anglo-Americans, an example of a new variety arising
within these few generations; and that, if we may trust to the
descriptions of observers, we are likely soon to have another such
example in Australia.

On passing from Humanity under its individual form, to Humanity as
socially embodied, we find the general law still more variously
exemplified. The change from the homogeneous to the heterogeneous is
displayed in the progress of civilization as a whole, as well as in the
progress of every nation; and is still going on with increasing
rapidity. As we see in existing barbarous tribes, society in its first
and lowest form is a homogeneous aggregation of individuals having like
powers and like functions: the only marked difference of function being
that which accompanies difference of sex. Every man is warrior, hunter,
fisherman, tool-maker, builder; every woman performs the same
drudgeries. Very early, however, in the course of social evolution,
there arises an incipient differentiation between the governing and the
governed. Some kind of chieftainship seems coeval with the first advance
from the state of separate wandering families to that of a nomadic
tribe. The authority of the strongest or the most cunning makes itself
felt among a body of savages as in a herd of animals, or a posse of
schoolboys. At first, however, it is indefinite, uncertain; is shared by
others of scarcely inferior power; and is unaccompanied by any
difference in occupation or style of living: the first ruler kills his
own game, makes his own weapons, builds his own hut, and, economically
considered, does not differ from others of his tribe. Gradually, as the
tribe progresses, the contrast between the governing and the governed
grows more decided. Supreme power becomes hereditary in one family; the
head of that family, ceasing to provide for his own wants, is served by
others; and he begins to assume the sole office of ruling. At the same
time there has been arising a co-ordinate species of government--that
of Religion. As all ancient records and traditions prove, the earliest
rulers are regarded as divine personages. The maxims and commands they
uttered during their lives are held sacred after their deaths, and are
enforced by their divinely-descended successors; who in their turns are
promoted to the pantheon of the race, here to be worshipped and
propitiated along with their predecessors: the most ancient of whom is
the supreme god, and the rest subordinate gods. For a long time these
connate forms of government--civil and religious--remain closely
associated. For many generations the king continues to be the chief
priest, and the priesthood to be members of the royal race. For many
ages religious law continues to include more or less of civil
regulation, and civil law to possess more or less of religious sanction;
and even among the most advanced nations these two controlling agencies
are by no means completely separated from each other. Having a common
root with these, and gradually diverging from them, we find yet another
controlling agency--that of Ceremonial usages. All titles of honour are
originally the names of the god-king; afterwards of the god and the
king; still later of persons of high rank; and finally come, some of
them, to be used between man and man. All forms of complimentary address
were at first the expressions of submission from prisoners to their
conqueror, or from subjects to their ruler, either human or
divine--expressions which were afterwards used to propitiate subordinate
authorities, and slowly descended into ordinary intercourse. All modes
of salutation were once obeisances made before the monarch and used in
worship of him after his death. Presently others of the god-descended
race were similarly saluted; and by degrees some of the salutations
have become the due of all.[3] Thus, no sooner does the
originally-homogeneous social mass differentiate  into the governed and
the governing parts, than this last exhibits an incipient
differentiation into religious and secular--Church and State; while at
the same time there begins to be differentiated from both, that less
definite species of government which rules our daily intercourse--a
species of government which, as we may see in heralds' colleges, in
books of the peerage, in masters of ceremonies, is not without a certain
embodiment of its own. Each of these is itself subject to successive
differentiations. In the course of ages, there arises, as among
ourselves, a highly complex political organization of monarch,
ministers, lords and commons, with their subordinate administrative
departments, courts of justice, revenue offices, &c., supplemented in
the provinces by municipal governments, county governments, parish or
union governments--all of them more or less elaborated. By its side
there grows up a highly complex religious organization, with its various
grades of officials, from archbishops down to sextons, its colleges,
convocations, ecclesiastical courts, &c.; to all which must be added the
ever-multiplying independent sects, each with its general and local
authorities. And at the same time there is developed a highly complex
aggregation of customs, manners, and temporary fashions, enforced by
society at large, and serving to control those minor transactions
between man and man which are not regulated by civil and religious law.
Moreover, it is to be observed that this increasing heterogeneity in the
governmental appliances of each nation, has been accompanied by an
increasing heterogeneity in the assemblage of governmental appliances of
different nations: all nations being more or less unlike in their
political systems and legislation, in their creeds and religious
institutions, in their customs and ceremonial usages.

Simultaneously there has been going on a second differentiation of a
more familiar kind; that, namely, by which the mass of the community has
been segregated into distinct classes and orders of workers. While the
governing part has undergone the complex development above detailed, the
governed part has undergone an equally complex development, which has
resulted in that minute division of labour characterizing advanced
nations. It is needless to trace out this progress from its first
stages, up through the caste-divisions of the East and the incorporated
guilds of Europe, to the elaborate producing and distributing
organization existing among ourselves. It has been an evolution which,
beginning with a tribe whose members severally perform the same actions
each for himself, ends with a civilized community whose members
severally perform different actions for each other; and an evolution
which has transformed the solitary producer of any one commodity into a
combination of producers who, united under a master, take separate parts
in the manufacture of such commodity. But there are yet other and higher
phases of this advance from the homogeneous to the heterogeneous in the
industrial organization of society. Long after considerable progress has
been made in the division of labour among different classes of workers,
there is still little or no division of labour among the widely
separated parts of the community: the nation continues comparatively
homogeneous in the respect that in each district the same occupations
are pursued. But when roads and other means of transit become numerous
and good, the different districts begin to assume different functions,
and to become mutually dependent. The calico manufacture locates itself
in this county, the woollen-cloth manufacture in that; silks are
produced here, lace there; stockings in one place, shoes in another;
pottery, hardware, cutlery, come to have their special towns; and
ultimately every locality becomes more or less distinguished from the
rest by the leading occupation carried on in it. This subdivision of
functions shows itself not only among the different parts of the same
nation, but among different nations. That exchange of commodities which
free-trade is increasing so largely, will ultimately have the effect of
specializing, in a greater or less degree, the industry of each people.
So that, beginning with a barbarous tribe, almost if not quite
homogeneous in the functions of its members, the progress has been, and
still is, towards an economic aggregation of the whole human race;
growing ever more heterogeneous in respect of the separate functions
assumed by separate nations, the separate functions assumed by the local
sections of each nation, the separate functions assumed by the many
kinds of makers and traders in each town, and the separate functions
assumed by the workers united in producing each commodity.

The law thus clearly exemplified in the evolution of the social
organism, is exemplified with equal clearness in the evolution of all
products of human thought and action; whether concrete or abstract, real
or ideal. Let us take Language as our first illustration.

The lowest form of language is the exclamation, by which an entire idea
is vaguely conveyed through a single sound, as among the lower animals.
That human language ever consisted solely of exclamations, and so was
strictly homogeneous in respect of its parts of speech, we have no
evidence. But that language can be traced down to a form in which nouns
and verbs are its only elements, is an established fact. In the gradual
multiplication of parts of speech out of these primary ones--in the
differentiation of verbs into active and passive, of nouns into abstract
and concrete--in the rise of distinctions of mood, tense, person, of
number and case--in the formation of auxiliary verbs, of adjectives,
adverbs, pronouns, prepositions, articles--in the divergence of those
orders, genera, species, and varieties of parts of speech by which
civilized races express minute modifications of meaning--we see a change
from the homogeneous to the heterogeneous. Another aspect under which we
may trace the development of language is the divergence of words having
common origins. Philology early disclosed the truth that in all
languages words may be grouped into families, the members of each of
which are allied by their derivation. Names springing from a primitive
root, themselves become the parents of other names still further
modified. And by the aid of those systematic modes which presently
arise, of making derivatives and forming compound terms, there is
finally developed a tribe of words so heterogeneous in sound and
meaning, that to the uninitiated it seems incredible they should be
nearly related. Meanwhile from other roots there are being evolved other
such tribes, until there results a language of some sixty thousand or
more unlike words, signifying as many unlike objects, qualities, acts.
Yet another way in which language in general advances from the
homogeneous to the heterogeneous, is in the multiplication of languages.
Whether all languages have grown from one stock, or whether, as some
philologists think, they have grown from two or more stocks, it is clear
that since large groups of languages, as the Indo-European, are of one
parentage, they have become distinct through a process of continuous
divergence. The same diffusion over the Earth's surface which has led to
differentiations of race, has simultaneously led to differentiations of
speech: a truth which we see further illustrated in each nation by the
distinct dialects found in separate districts. Thus the progress of
Language conforms to the general law, alike in the evolution of
languages, in the evolution of families of words, and in the evolution
of parts of speech.

On passing from spoken to written language, we come upon several classes
of facts, having similar implications. Written language is connate with
Painting and Sculpture; and at first all three are appendages of
Architecture, and have a direct connection with the primary form of all
Government--the theocratic. Merely noting by the way the fact that
sundry wild races, as for example the Australians and the tribes of
South Africa, are given to depicting personages and events upon the
walls of caves, which are probably regarded as sacred places, let us
pass to the case of the Egyptians. Among them, as also among the
Assyrians, we find mural paintings used to decorate the temple of the
god and the palace of the king (which were, indeed, originally
identical); and as such they were governmental appliances in the same
sense as state-pageants and religious feasts were. They were
governmental appliances in another way: representing as they did the
worship of the god, the triumphs of the god-king, the submission of his
subjects, and the punishment of the rebellious. Further, they were
governmental, as being the products of an art reverenced by the people
as a sacred mystery. From the habitual use of this pictorial
representation there grew up the but-slightly-modified practice of
picture-writing--a practice which was found still extant among North
American peoples at the time they were discovered. By abbreviations
analogous to those still going on in our own written language, the most
frequently-recurring of these pictured figures were successively
simplified; and ultimately there grew up a system of symbols, most of
which had but distant resemblances to the things for which they stood.
The inference that the hieroglyphics of the Egyptians were thus
produced, is confirmed by the fact that the picture-writing of the
Mexicans was found to have given birth to a like family of ideographic
forms; and among them, as among the Egyptians, these had been partially
differentiated into the _kuriological_ or imitative, and the _tropical_
or symbolic; which were, however, used together in the same record. In
Egypt, written language underwent a further differentiation, whence
resulted the _hieratic_ and the _epistolographic_ or _enchorial_; both
of which are derived from the original hieroglyphic. At the same time we
find that for the expression of proper names, which could not be
otherwise conveyed, signs having phonetic values were employed; and
though it is alleged that the Egyptians never achieved complete
alphabetic writing, yet it can scarcely be doubted that these phonetic
symbols, occasionally used in aid of their ideographic ones, were the
germs of an alphabetic system. Once having become separate from
hieroglyphics, alphabetic writing itself underwent numerous
differentiations--multiplied alphabets were produced; between most of
which, however, more or less connection can still be traced. And in each
civilized nation there has now grown up, for the representation of one
set of sounds, several sets of written signs used for distinct purposes.
Finally, from writing diverged printing; which, uniform in kind as it
was at first, has since become multiform.

While written language was passing through its first stages of
development, the mural decoration which contained its root was being
differentiated into Painting and Sculpture. The gods, kings, men, and
animals represented, were originally marked by indented outlines and
coloured. In most cases these outlines were of such depth, and the
object they circumscribed so far rounded and marked out in its leading
parts, as to form a species of work intermediate between intaglio and
bas-relief. In other cases we see an advance upon this: the raised
spaces between the figures being chiselled off, and the figures
themselves appropriately tinted, a painted bas-relief was produced. The
restored Assyrian architecture at Sydenham exhibits this style of art
carried to greater perfection--the persons and things represented,
though still barbarously coloured, are carved out with more truth and in
greater detail: and in the winged lions and bulls used for the angles of
gateways, we may see a considerable advance towards a completely
sculptured figure; which, nevertheless, is still coloured, and still
forms part of the building. But while in Assyria the production of a
statue proper seems to have been little, if at all, attempted, we may
trace in Egyptian art the gradual separation of the sculptured figure
from the wall. A walk through the collection in the British Museum
shows this; while at the same time it affords an opportunity of
observing the traces which the independent statues bear of their
derivation from bas-relief: seeing that nearly all of them not only
display that fusion of the legs with one another and of the arms with
the body which is characteristic of bas-relief, but have the back united
from head to foot with a block which stands in place of the original
wall. Greece repeated the leading stages of this progress. On the
friezes of Greek Temples, were coloured bas-reliefs representing
sacrifices, battles, processions, games--all in some sort religious. The
pediments contained painted sculptures more or less united with the
tympanum, and having for subjects the triumphs of gods or heroes. Even
statues definitely separated from buildings were coloured; and only in
the later periods of Greek civilization does the differentiation of
Sculpture from Painting appear to have become complete. In Christian art
we may trace a parallel re-genesis. All early works of art throughout
Europe were religious in subject--represented Christs, crucifixions,
virgins, holy families, apostles, saints. They formed integral parts of
church architecture, and were among the means of exciting worship; as in
Roman Catholic countries they still are. Moreover, the sculptured
figures of Christ on the cross, of virgins, of saints, were coloured;
and it needs but to call to mind the painted madonnas still abundant in
continental churches and highways, to perceive the significant fact that
Painting and Sculpture continue in closest connection with each other
where they continue in closest connection with their parent. Even when
Christian sculpture became differentiated from painting, it was still
religious and governmental in its subjects--was used for tombs in
churches and statues of kings; while, at the same time, painting, where
not purely ecclesiastical, was applied to the decoration of palaces, and
besides representing royal personages, was mostly devoted to sacred
legends. Only in recent times have painting and sculpture become quite
separate and mainly secular. Only within these few centuries has
Painting been divided into historical, landscape, marine, architectural,
genre, animal, still-life, &c.; and Sculpture grown heterogeneous in
respect of the variety of real and ideal subjects with which it occupies
itself.

Strange as it seems then, we find that all forms of written language, of
Painting, and of Sculpture, have a common root in the politico-religious
decorations of ancient temples and palaces. Little resemblance as they
now have, the landscape that hangs against the wall, and the copy of the
_Times_ lying on the table, are remotely akin. The brazen face of the
knocker which the postman has just lifted, is related not only to the
woodcuts of the _Illustrated London News_ which he is delivering, but to
the characters of the _billet-doux_ which accompanies it. Between the
painted window, the prayer-book on which its light falls, and the
adjacent monument, there is consanguinity. The effigies on our coins,
the signs over shops, the coat of arms outside the carriage panel, and
the placards inside the omnibus, are, in common with dolls and
paper-hangings, lineally descended from the rude sculpture-paintings in
which ancient peoples represented the triumphs and worship of their
god-kings. Perhaps no example can be given which more vividly
illustrates the multiplicity and heterogeneity of the products that in
course of time may arise by successive differentiations from a common
stock.

Before passing to other classes of facts, it should be observed that the
evolution of the homogeneous into the heterogeneous is displayed not
only in the separation of Painting and Sculpture from Architecture and
from each other, and in the greater variety of subjects they embody, but
it is further shown in the structure of each work. A modern picture or
statue is of far more heterogeneous nature than an ancient one. An
Egyptian sculpture-fresco usually represents all its figures as at the
same distance from the eye; and so is less heterogeneous than a
painting that represents them as at various distances from the eye. It
exhibits all objects as exposed to the same degree of light; and so is
less heterogeneous than a painting which exhibits its different objects
and different parts of each object as in different degrees of light. It
uses chiefly the primary colours, and these in their full intensities;
and so is less heterogeneous than a painting which, introducing the
primary colours but sparingly, employs numerous intermediate tints, each
of heterogeneous composition, and differing from the rest not only in
quality but in strength. Moreover, we see in these early works great
uniformity of conception. The same arrangement of figures is perpetually
reproduced--the same actions, attitudes, faces, dresses. In Egypt the
modes of representation were so fixed that it was sacrilege to introduce
a novelty. The Assyrian bas-reliefs display parallel characters.
Deities, kings, attendants, winged-figures and animals, are time after
time depicted in like positions, holding like implements, doing like
things, and with like expression or non-expression of face. If a
palm-grove is introduced, all the trees are of the same height, have the
same number of leaves, and are equidistant. When water is imitated, each
wave is a counterpart of the rest; and the fish, almost always of one
kind, are evenly distributed over the surface. The beards of the kings,
the gods, and the winged-figures, are everywhere similar; as are the
manes of the lions, and equally so those of the horses. Hair is
represented throughout by one form of curl. The king's beard is quite
architecturally built up of compound tiers of uniform curls, alternating
with twisted tiers placed in a transverse direction, and arranged with
perfect regularity; and the terminal tufts of the bulls' tails are
represented in exactly the same manner. Without tracing out analogous
facts in early Christian art, in which, though less striking, they are
still visible, the advance in heterogeneity will be sufficiently
manifest on remembering that in the pictures of our own day the
composition is endlessly varied; the attitudes, faces, expressions,
unlike; the subordinate objects different in sizes, forms, textures; and
more or less of contrast even in the smallest details. Or, if we compare
an Egyptian statue, seated bolt upright on a block, with hands on knees,
fingers parallel, eyes looking straight forward, and the two sides
perfectly symmetrical in every particular, with a statue of the advanced
Greek school or the modern school, which is asymmetrical in respect of
the attitude of the head, the body, the limbs, the arrangement of the
hair, dress, appendages, and in its relations to neighbouring objects,
we shall see the change from the homogeneous to the heterogeneous
clearly manifested.

In the co-ordinate origin and gradual differentiation of Poetry, Music,
and Dancing, we have another series of illustrations. Rhythm in words,
rhythm in sounds, and rhythm in motions, were in the beginning parts of
the same thing, and have only in process of time become separate things.
Among existing barbarous tribes we find them still united. The dances of
savages are accompanied by some kind of monotonous chant, the clapping
of hands, the striking of rude instruments: there are measured
movements, measured words, and measured tones. The early records of
historic races similarly show these three forms of metrical action
united in religious festivals. In the Hebrew writings we read that the
triumphal ode composed by Moses on the defeat of the Egyptians, was sung
to an accompaniment of dancing and timbrels. The Israelites danced and
sung "at the inauguration of the golden calf. And as it is generally
agreed that this representation of the Deity was borrowed from the
mysteries of Apis, it is probable that the dancing was copied from that
of the Egyptians on those occasions." Again, in Greece the like relation
is everywhere seen: the original type being there, as probably in other
cases, a simultaneous chanting and mimetic representation of the life
and adventures of the hero or the god. The Spartan dances were
accompanied by hymns and songs; and in general the Greeks had "no
festivals or religious assemblies but what were accompanied with songs
and dances"--both of them being forms of worship used before altars.
Among the Romans, too, there were sacred dances: the Salian and
Lupercalian being named as of that kind. And even in Christian
countries, as at Limoges, in comparatively recent times, the people have
danced in the choir in honour of a saint. The incipient separation of
these once-united arts from each other and from religion, was early
visible in Greece. Probably diverging from dances partly religious,
partly warlike, as the Corybantian, came the war-dances proper, of which
there were various kinds. Meanwhile Music and Poetry, though still
united, came to have an existence separate from Dancing. The primitive
Greek poems, religious in subject, were not recited but chanted; and
though at first the chant of the poet was accompanied by the dance of
the chorus, it ultimately grew into independence. Later still, when the
poem had been differentiated into epic and lyric--when it became the
custom to sing the lyric and recite the epic--poetry proper was born. As
during the same period musical instruments were being multiplied, we may
presume that music came to have an existence apart from words. And both
of them were beginning to assume other forms besides the religious.
Facts having like implications might be cited from the histories of
later times and peoples; as the practices of our own early minstrels,
who sang to the harp heroic narratives versified by themselves to music
of their own composition: thus uniting the now separate offices of poet,
composer, vocalist, and instrumentalist. But, without further
illustration, the common origin and gradual differentiation of Dancing,
Poetry, and Music will be sufficiently manifest.

The advance from the homogeneous to the heterogeneous is displayed not
only in the separation of these arts from each other and from religion,
but also in the multiplied differentiations which each of them
afterwards undergoes. Not to dwell upon the numberless kinds of dancing
that have, in course of time, come into use: and not to occupy space in
detailing the progress of poetry, as seen in the development of the
various forms of metre, of rhyme, and of general organization; let us
confine our attention to music as a type of the group. As implied by the
customs of still extant barbarous races, the first musical instruments
were, without doubt, percussive--sticks, calabashes, tom-toms--and were
used simply to mark the time of the dance; and in this constant
repetition of the same sound, we see music in its most homogeneous form.
The Egyptians had a lyre with three strings. The early lyre of the
Greeks had four, constituting their tetrachord. In course of some
centuries lyres of seven and eight strings were employed; and, by the
expiration of a thousand years, they had advanced to their "great
system" of the double octave. Through all which changes there of course
arose a greater heterogeneity of melody. Simultaneously there came into
use the different modes--Dorian, Ionian, Phrygian, Æolian, and
Lydian--answering to our keys; and of these there were ultimately
fifteen. As yet, however, there was but little heterogeneity in the time
of their music. Instrumental music being at first merely the
accompaniment of vocal music, and vocal music being subordinated to
words,--the singer being also the poet, chanting his own compositions
and making the lengths of his notes agree with the feet of his
verses,--there resulted a tiresome uniformity of measure, which, as Dr.
Burney says, "no resources of melody could disguise." Lacking the
complex rhythm obtained by our equal bars and unequal notes, the only
rhythm was that produced by the quantity of the syllables, and was of
necessity comparatively monotonous. And further, it maybe observed that
the chant thus resulting, being like recitative, was much less clearly
differentiated from ordinary speech than is our modern song.
Nevertheless, in virtue of the extended range of notes in use, the
variety of modes, the occasional variations of time consequent on
changes of metre, and the multiplication of instruments, music had,
towards the close of Greek civilization, attained to considerable
heterogeneity--not indeed as compared with our music, but as compared
with that which preceded it. Still, there existed nothing but melody:
harmony was unknown. It was not until Christian church-music had reached
some development, that music in parts was evolved; and then it came into
existence through a very unobtrusive differentiation. Difficult as it
may be to conceive _a priori_ how the advance from melody to harmony
could take place without a sudden leap, it is none the less true that it
did so. The circumstance which prepared the way for it was the
employment of two choirs singing alternately the same air. Afterwards it
became the practice--very possibly first suggested by a mistake--for the
second choir to commence before the first had ceased; thus producing a
fugue. With the simple airs then in use, a partially-harmonious fugue
might not improbably thus result: and a very partially-harmonious fugue
satisfied the ears of that age, as we know from still preserved
examples. The idea having once been given, the composing of airs
productive of fugal harmony would naturally grow up, as in some way it
_did_ grow up, out of this alternate choir-singing. And from the fugue
to concerted music of two, three, four, and more parts, the transition
was easy. Without pointing out in detail the increasing complexity that
resulted from introducing notes of various lengths, from the
multiplication of keys, from the use of accidentals, from varieties of
time, and so forth, it needs but to contrast music as it is, with music
as it was, to see how immense is the increase of heterogeneity. We see
this if, looking at music in its _ensemble_, we enumerate its many
different genera and species--if we consider the divisions into vocal,
instrumental, and mixed; and their subdivisions into music for
different voices and different instruments--if we observe the many forms
of sacred music, from the simple hymn, the chant, the canon, motet,
anthem, &c., up to the oratorio; and the still more numerous forms of
secular music, from the ballad up to the serenata, from the instrumental
solo up to the symphony. Again, the same truth is seen on comparing any
one sample of aboriginal music with a sample of modern music--even an
ordinary song for the piano; which we find to be relatively very
heterogeneous, not only in respect of the variety in the pitches and in
the lengths of the notes, the number of different notes sounding at the
same instant in company with the voice, and the variations of strength
with which they are sounded and sung, but in respect of the changes of
key, the changes of time, the changes of _timbre_ of the voice, and the
many other modifications of expression. While between the old monotonous
dance-chant and a grand opera of our own day, with its endless
orchestral complexities and vocal combinations, the contrast in
heterogeneity is so extreme that it seems scarcely credible that the one
should have been the ancestor of the other.

Were they needed, many further illustrations might be cited. Going back
to the early time when the deeds of the god-king were recorded in
picture-writings on the walls of temples and palaces, and so constituted
a rude literature, we might trace the development of Literature through
phases in which, as in the Hebrew Scriptures, it presents in one work
theology, cosmogony, history, biography, law, ethics, poetry; down to
its present heterogeneous development, in which its separated divisions
and subdivisions are so numerous and varied as to defy complete
classification. Or we might trace out the evolution of Science;
beginning with the era in which it was not yet differentiated from Art,
and was, in union with Art, the handmaid of Religion; passing through
the era in which the sciences were so few and rudimentary, as to be
simultaneously cultivated by the same men; and ending with the era in
which the genera and species are so numerous that few can enumerate
them, and no one can adequately grasp even one genus. Or we might do the
like with Architecture, with the Drama, with Dress. But doubtless the
reader is already weary of illustrations; and our promise has been amply
fulfilled. Abundant proof has been given that the law of organic
development formulated by von Baer, is the law of all development. The
advance from the simple to the complex, through a process of successive
differentiations, is seen alike in the earliest changes of the Universe
to which we can reason our way back, and in the earliest changes which
we can inductively establish; it is seen in the geologic and climatic
evolution of the Earth; it is seen in the unfolding of every single
organism on its surface, and in the multiplication of kinds of
organisms; it is seen in the evolution of Humanity, whether contemplated
in the civilized individual, or in the aggregate of races; it is seen in
the evolution of Society in respect alike of its political, its
religious, and its economical organization; and it is seen in the
evolution of all those endless concrete and abstract products of human
activity which constitute the environment of our daily life. From the
remotest past which Science can fathom, up to the novelties of
yesterday, that in which progress essentially consists, is the
transformation of the homogeneous into the heterogeneous.

       *       *       *       *       *

And now, must not this uniformity of procedure be a consequence of some
fundamental necessity? May we not rationally seek for some all-pervading
principle which determines this all-pervading process of things? Does
not the universality of the _law_ imply a universal _cause_?

That we can comprehend such cause, noumenally considered, is not to be
supposed. To do this would be to solve that ultimate mystery which must
ever transcend human intelligence. But it still may be possible for us
to reduce the law of all progress, above set forth, from the condition
of an empirical generalization, to the condition of a rational
generalization. Just as it was possible to interpret Kepler's laws as
necessary consequences of the law of gravitation; so it may be possible
to interpret this law of progress, in its multiform manifestations, as
the necessary consequence of some similarly universal principle. As
gravitation was assignable as the _cause_ of each of the groups of
phenomena which Kepler generalized; so may some equally simple attribute
of things be assignable as the cause of each of the groups of phenomena
generalized in the foregoing pages. We may be able to affiliate all
these varied evolutions of the homogeneous into the heterogeneous, upon
certain facts of immediate experience, which, in virtue of endless
repetition, we regard as necessary.

The probability of a common cause, and the possibility of formulating
it, being granted, it will be well, first, to ask what must be the
general characteristics of such cause, and in what direction we ought to
look for it. We can with certainty predict that it has a high degree of
abstractness; seeing that it is common to such infinitely-varied
phenomena. We need not expect to see in it an obvious solution of this
or that form of progress; because it is equally concerned with forms of
progress bearing little apparent resemblance to them: its association
with multiform orders of facts, involves its dissociation from any
particular order of facts. Being that which determines progress of every
kind--astronomic, geologic, organic, ethnologic, social, economic,
artistic, &c.--it must be involved with some fundamental trait displayed
in common by these; and must be expressible in terms of this fundamental
trait. The only obvious respect in which all kinds of progress are
alike, is, that they are modes of _change_; and hence, in some
characteristic of changes in general, the desired solution will probably
be found. We may suspect _a priori_ that in some universal law of change
lies the explanation of this universal transformation of the
homogeneous into the heterogeneous.

Thus much premised, we pass at once to the statement of the law, which
is this:--_Every active force produces more than one change--every cause
produces more than one effect._

To make this proposition comprehensible, a few examples must be given.
When one body strikes another, that which we usually regard as the
effect, is a change of position or motion in one or both bodies. But a
moment's thought shows us that this is a very incomplete view of the
matter. Besides the visible mechanical result, sound is produced; or, to
speak accurately, a vibration in one or both bodies, which is
communicated to the surrounding air; and under some circumstances we
call this the effect. Moreover, the air has not only been made to
undulate, but has had currents caused in it by the transit of the
bodies. Further, there is a disarrangement of the particles of the two
bodies in the neighbourhood of their point of collision; amounting, in
some cases, to a visible condensation. Yet more, this condensation is
accompanied by the disengagement of heat. In some cases a spark--that
is, light--results, from the incandescence of a portion struck off; and
sometimes this incandescence is associated with chemical combination.
Thus, by the mechanical force expended in the collision, at least five,
and often more, different kinds of changes have been produced. Take,
again, the lighting of a candle. Primarily this is a chemical change
consequent on a rise of temperature. The process of combination having
once been started by extraneous heat, there is a continued formation of
carbonic acid, water, &c.--in itself a result more complex than the
extraneous heat that first caused it. But accompanying this process of
combination there is a production of heat; there is a production of
light; there is an ascending column of hot gases generated; there are
inflowing currents set going in the surrounding air. Moreover, the
complicating of effects does not end here: each of the several changes
produced becomes the parent of further changes. The carbonic acid given
off will by and by combine with some base; or under the influence of
sunshine give up its carbon to the leaf of a plant. The water will
modify the hygrometric state of the air around; or, if the current of
hot gases containing it comes against a cold body, will be condensed:
altering the temperature of the surface it covers. The heat given out
melts the subjacent tallow, and expands whatever it warms. The light,
falling on various substances, calls forth from them reactions by which
its composition is modified; and so divers colours are produced.
Similarly even with these secondary actions, which may be traced out
into ever-multiplying ramifications, until they become too minute to be
appreciated. And thus it is with all changes whatever. No case can be
named in which an active force does not evolve forces of several kinds,
and each of these, other groups of forces. Universally the effect is
more complex than the cause.

Doubtless the reader already foresees the course of our argument. This
multiplication of effects, which is displayed in every event of to-day,
has been going on from the beginning; and is true of the grandest
phenomena of the universe as of the most insignificant. From the law
that every active force produces more than one change, it is an
inevitable corollary that during the past there has been an ever-growing
complication of things. Throughout creation there must have gone on, and
must still go on, a never-ceasing transformation of the homogeneous into
the heterogeneous. Let us trace this truth in detail.

Without committing ourselves to it as more than a speculation, though a
highly probable one, let us again commence with the evolution of the
Solar System out of a nebulous medium. The hypothesis is that from the
mutual attraction of the molecules of a diffused mass whose form is
unsymmetrical, there results not only condensation but rotation. While
the condensation and the rate of rotation go on increasing, the
approach of the molecules is necessarily accompanied by an increasing
temperature. As the temperature rises, light begins to be evolved; and
ultimately there results a revolving sphere of fluid matter radiating
intense heat and light--a sun. There are reasons for believing that, in
consequence of the higher tangential velocity originally possessed by
the outer parts of the condensing nebulous mass, there will be
occasional detachments of rotating rings; and that, from the breaking up
of these nebulous rings, there will arise masses which in the course of
their condensation repeat the actions of the parent mass, and so produce
planets and their satellites--an inference strongly supported by the
still extant rings of Saturn. Should it hereafter be satisfactorily
shown that planets and satellites were thus generated, a striking
illustration will be afforded of the highly heterogeneous effects
produced by the primary homogeneous cause; but it will serve our present
purpose to point to the fact that from the mutual attraction of the
particles of an irregular nebulous mass there result condensation,
rotation, heat, and light.

It follows as a corollary from the Nebular Hypothesis, that the Earth
must once have been incandescent; and whether the Nebular Hypothesis be
true or not, this original incandescence of the Earth is now inductively
established--or, if not established, at least rendered so highly
probable that it is an accepted geological doctrine. Let us look first
at the astronomical attributes of this once molten globe. From its
rotation there result the oblateness of its form, the alternations of
day and night, and (under the influence of the moon and in a smaller
degree the sun) the tides, aqueous and atmospheric. From the inclination
of its axis, there result the many differences of the seasons, both
simultaneous and successive, that pervade its surface, and from the same
cause joined with the action of the moon on the equatorial protuberance
there results the precession of the equinoxes. Thus the multiplication
of effects is obvious. Several of the differentiations due to the
gradual cooling of the Earth have been already noticed--as the formation
of a crust, the solidification of sublimed elements, the precipitation
of water, &c.,--and we here again refer to them merely to point out that
they are simultaneous effects of the one cause, diminishing heat. Let us
now, however, observe the multiplied changes afterwards arising from the
continuance of this one cause. The cooling of the Earth involves its
contraction. Hence the solid crust first formed is presently too large
for the shrinking nucleus; and as it cannot support itself, inevitably
follows the nucleus. But a spheroidal envelope cannot sink down into
contact with a smaller internal spheroid, without disruption: it must
run into wrinkles as the rind of an apple does when the bulk of its
interior decreases from evaporation. As the cooling progresses and the
envelope thickens, the ridges consequent on these contractions will
become greater, rising ultimately into hills and mountains; and the
later systems of mountains thus produced will not only be higher, as we
find them to be, but will be longer, as we also find them to be. Thus,
leaving out of view other modifying forces, we see what immense
heterogeneity of surface has arisen from the one cause, loss of heat--a
heterogeneity which the telescope shows us to be paralleled on the face
of Mars, and which in the moon too, where aqueous and atmospheric
agencies have been absent, it reveals under a somewhat different form.
But we have yet to notice another kind of heterogeneity of surface
similarly and simultaneously caused. While the Earth's crust was still
thin, the ridges produced by its contraction must not only have been
small, but the spaces between these ridges must have rested with great
evenness upon the subjacent liquid spheroid; and the water in those
arctic and antarctic regions in which it first condensed, must have been
evenly distributed. But as fast as the crust thickened and gained
corresponding strength, the lines of fracture from time to time caused
in it, must have occurred at greater distances apart; the intermediate
surfaces must have followed the contracting nucleus with less
uniformity; and there must have resulted larger areas of land and water.
If any one, after wrapping up an orange in tissue paper, and observing
not only how small are the wrinkles, but how evenly the intervening
spaces lie upon the surface of the orange, will then wrap it up in thick
cartridge-paper, and note both the greater height of the ridges and the
larger spaces throughout which the paper does not touch the orange, he
will realize the fact that, as the Earth's solid envelope grew thicker,
the areas of elevation and depression increased. In place of islands
homogeneously dispersed amid an all-embracing sea, there must have
gradually arisen heterogeneous arrangements of continent and ocean. Once
more, this double change in the extent and in the elevation of the
lands, involved yet another species of heterogeneity--that of
coast-line. A tolerably even surface raised out of the ocean must have a
simple, regular sea-margin; but a surface varied by table-lands and
intersected by mountain-chains must, when raised out of the ocean, have
an outline extremely irregular both in its leading features and in its
details. Thus, multitudinous geological and geographical results are
slowly brought about by this one cause--the contraction of the Earth.

When we pass from the agency termed igneous, to aqueous and atmospheric
agencies, we see the like ever-growing complications of effects. The
denuding actions of air and water, joined with those of changing
temperature, have, from the beginning, been modifying every exposed
surface. Oxidation, heat, wind, frost, rain, glaciers, rivers, tides,
waves, have been unceasingly producing disintegration; varying in kind
and amount according to local circumstances. Acting upon a tract of
granite, they here work scarcely an appreciable effect; there cause
exfoliations of the surface, and a resulting heap of _débris_ and
boulders; and elsewhere, after decomposing the feldspar into a white
clay, carry away this and the accompanying quartz and mica, and deposit
them in separate beds, fluviatile and marine. When the exposed land
consists of several unlike kinds of sedimentary strata, or igneous
rocks, or both, denudation produces changes proportionably more
heterogeneous. The formations being disintegrable in different degrees,
there follows an increased irregularity of surface. The areas drained by
different rivers being differently constituted, these rivers carry down
to the sea different combinations of ingredients; and so sundry new
strata of unlike compositions are formed. And here we may see very
simply illustrated, the truth, which we shall presently have to trace
out in more involved cases, that in proportion to the heterogeneity of
the object or objects on which any force expends itself, is the
heterogeneity of the effects. A continent of complex structure, exposing
many strata irregularly distributed, raised to various levels, tilted up
at all angles, will, under the same denuding agencies, give origin to
innumerable and involved results: each district must be differently
modified; each river must carry down a different kind of detritus; each
deposit must be differently distributed by the entangled currents, tidal
and other, which wash the contorted shores; and this multiplication of
results must manifestly be greatest where the complexity of surface is
greatest.

Here we might show how the general truth, that every active force
produces more than one change, is again exemplified in the
highly-involved flow of the tides, in the ocean currents, in the winds,
in the distribution of rain, in the distribution of heat, and so forth.
But not to dwell upon these, let us, for the fuller elucidation of this
truth in relation to the inorganic world, consider what would be the
consequences of some extensive cosmical catastrophe--say the subsidence
of Central America. The immediate results of the disturbance would
themselves be sufficiently complex. Besides the numberless dislocations
of strata, the ejections of igneous matter, the propagation of
earthquake vibrations thousands of miles around, the loud explosions,
and the escape of gases; there would be the rush of the Atlantic and
Pacific Oceans to fill the vacant space, the subsequent recoil of
enormous waves, which would traverse both these oceans and produce
myriads of changes along their shores, the corresponding atmospheric
waves complicated by the currents surrounding each volcanic vent, and
the electrical discharges with which such disturbances are accompanied.
But these temporary effects would be insignificant compared with the
permanent ones. The currents of the Atlantic and Pacific would be
altered in their directions and amounts. The distribution of heat
achieved by those ocean currents would be different from what it is. The
arrangement of the isothermal lines, not only on neighbouring
continents, but even throughout Europe, would be changed. The tides
would flow differently from what they do now. There would be more or
less modification of the winds in their periods, strengths, directions,
qualities. Rain would fall scarcely anywhere at the same times and in
the same quantities as at present. In short, the meteorological
conditions thousands of miles off, on all sides, would be more or less
revolutionized. Thus, without taking into account the infinitude of
modifications which these changes would produce upon the flora and
fauna, both of land and sea, the reader will perceive the immense
heterogeneity of the results wrought out by one force, when that force
expends itself upon a previously complicated area; and he will draw the
corollary that from the beginning the complication has advanced at an
increasing rate.

Before going on to show how organic progress also depends on the law
that every force produces more than one change, we have to notice the
manifestation of this law in yet another species of inorganic
progress--namely, chemical. The same general causes that have wrought
out the heterogeneity of the Earth, physically considered, have
simultaneously wrought out its chemical heterogeneity. There is every
reason to believe that at an extreme heat the elements cannot combine.
Even under such heat as can be artificially produced, some very strong
affinities yield, as, for instance, that of oxygen for hydrogen; and the
great majority of chemical compounds are decomposed at much lower
temperatures. But without insisting on the highly probable inference,
that when the Earth was in its first state of incandescence there were
no chemical combinations at all, it will suffice for our purpose to
point to the unquestionable fact that the compounds which can exist at
the highest temperatures, and which must, therefore, have been the first
that were formed as the Earth cooled, are those of the simplest
constitutions. The protoxides--including under that head the alkalies,
earths, &c.--are, as a class, the most stable compounds we know: most of
them resisting decomposition by any heat we can generate. These are
combinations of the simplest order--are but one degree less homogeneous
than the elements themselves. More heterogeneous, less stable, and
therefore later in the Earth's history, are the deutoxides, tritoxides,
peroxides, &c.; in which two, three, four, or more atoms of oxygen are
united with one atom of metal or other element. Higher than these in
heterogeneity are the hydrates; in which an oxide of hydrogen, united
with an oxide of some other element, forms a substance whose atoms
severally contain at least four ultimate atoms of three different kinds.
Yet more heterogeneous and less stable still are the salts; which
present us with molecules each made up of five, six, seven, eight, ten,
twelve, or more atoms, of three, if not more, kinds. Then there are the
hydrated salts, of a yet greater heterogeneity, which undergo partial
decomposition at much lower temperatures. After them come the further
complicated supersalts and double salts, having a stability again
decreased; and so throughout. Without entering into qualifications for
which space fails, we believe no chemist will deny it to be a general
law of these inorganic combinations that, _other things equal_, the
stability decreases as the complexity increases. When we pass to the
compounds of organic chemistry, we find this general law still further
exemplified: we find much greater complexity and much less stability. A
molecule of albumen, for instance, consists of 482 ultimate atoms of
five different kinds. Fibrine, still more intricate in constitution,
contains in each molecule, 298 atoms of carbon, 49 of nitrogen, 2 of
sulphur, 228 of hydrogen, and 92 of oxygen--in all, 669 atoms; or, more
strictly speaking, equivalents. And these two substances are so unstable
as to decompose at quite ordinary temperatures; as that to which the
outside of a joint of roast meat is exposed. Thus it is manifest that
the present chemical heterogeneity of the Earth's surface has arisen by
degrees, as the decrease of heat has permitted; and that it has shown
itself in three forms--first, in the multiplication of chemical
compounds; second, in the greater number of different elements contained
in the more modern of these compounds; and third, in the higher and more
varied multiples in which these more numerous elements combine.

To say that this advance in chemical heterogeneity is due to the one
cause, diminution of the Earth's temperature, would be to say too much;
for it is clear that aqueous and atmospheric agencies have been
concerned; and further, that the affinities of the elements themselves
are implied. The cause has all along been a composite one: the cooling
of the Earth having been simply the most general of the concurrent
causes, or assemblage of conditions. And here, indeed, it may be
remarked that in the several classes of facts already dealt with
(excepting, perhaps, the first), and still more in those with which we
shall presently deal, the causes are more or less compound; as indeed
are nearly all causes with which we are acquainted. Scarcely any
change can rightly be ascribed to one agency alone, to the neglect of
the permanent or temporary conditions under which only this agency
produces the change. But as it does not materially affect our argument,
we prefer, for simplicity's sake, to use throughout the popular mode of
expression. Perhaps it will be further objected, that to assign loss of
heat as the cause of any changes, is to attribute these changes not to a
force, but to the absence of a force. And this is true. Strictly
speaking, the changes should be attributed to those forces which come
into action when the antagonist force is withdrawn. But though there is
inaccuracy in saying that the freezing of water is due to the loss of
its heat, no practical error arises from it; nor will a parallel laxity
of expression vitiate our statements respecting the multiplication of
effects. Indeed, the objection serves but to draw attention to the fact,
that not only does the exertion of a force produce more than one change,
but the withdrawal of a force produces more than one change.

Returning to the thread of our exposition, we have next to trace,
throughout organic progress, this same all-pervading principle. And
here, where the evolution of the homogeneous into the heterogeneous was
first observed, the production of many effects by one cause is least
easy to demonstrate. The development of a seed into a plant, or an ovum
into an animal, is so gradual, while the forces which determine it are
so involved, and at the same time so unobtrusive, that it is difficult
to detect the multiplication of effects which is elsewhere so obvious.
But, guided by indirect evidence, we may safely conclude that here too
the law holds. Note, first, how numerous are the changes which any
marked action works upon an adult organism--a human being, for instance.
An alarming sound or sight, besides the impressions on the organs of
sense and the nerves, may produce a start, a scream, a distortion of
the face, a trembling consequent on general muscular relaxation, a burst
of perspiration, a rush of blood to the brain, followed possibly by
arrest of the heart's action and by syncope; and if the subject be
feeble, an indisposition with its long train of complicated symptoms may
set in. Similarly in cases of disease. A minute portion of the small-pox
virus introduced into the system, will, in a severe case, cause, during
the first stage, rigors, heat of skin, accelerated pulse, furred tongue,
loss of appetite, thirst, epigastric uneasiness, vomiting, headache,
pains in the back and limbs, muscular weakness, convulsions, delirium,
&c.; in the second stage, cutaneous eruption, itching, tingling, sore
throat, swelled fauces, salivation, cough, hoarseness, dyspnoea, &c.;
and in the third stage, oedematous inflammations, pneumonia, pleurisy,
diarrhoea, inflammation of the brain, ophthalmia, erysipelas, &c.:
each of which enumerated symptoms is itself more or less complex.
Medicines, special foods, better air, might in like manner be instanced
as producing multipled results. Now it needs only to consider that the
many changes thus wrought by one force upon an adult organism, will be
in part paralleled in an embryo organism, to understand how here also,
the evolution of the homogeneous into the heterogeneous may be due to
the production of many effects by one cause. The external heat, which,
falling on a matter having special proclivities, determines the first
complications of the germ, may, by acting on these, superinduce further
complications; upon these still higher and more numerous ones; and so on
continually: each organ as it is developed serving, by its actions and
reactions on the rest, to initiate new complexities. The first
pulsations of the foetal heart must simultaneously aid the unfolding
of every part. The growth of each tissue, by taking from the blood
special proportions of elements, must modify the constitution of the
blood; and so must modify the nutrition of all the other tissues. The
heart's action, implying as it does a certain waste, necessitates an
addition to the blood of effete matters, which must influence the rest
of the system, and perhaps, as some think, cause the formation of
excretory organs. The nervous connexions established among the viscera
must further multiply their mutual influences; and so continually. Still
stronger becomes the probability of this view when we call to mind the
fact, that the same germ may be evolved into different forms according
to circumstances. Thus, during its earlier stages, every embryo is
sexless--becomes either male or female as the balance of forces acting
on it determines. Again, it is a well-established fact that the larva of
a working-bee will develop into a queen-bee, if before it is too late,
its food be changed to that on which the larvæ of queen-bees are fed.
All which instances suggest that the proximate cause of each advance in
embryonic complication is the action of incident forces upon the
complication previously existing. Indeed, we may find _a priori_ reason
to think that the evolution proceeds after this manner. For since no
germ, animal or vegetal, contains the slightest rudiment or indication
of the future organism--since the microscope has shown us that the first
process set up in every fertilized germ, is a process of repeated
spontaneous fissions ending in the production of a mass of cells, not
one of which exhibits any special character; there seems no alternative
but to suppose that the partial organization at any moment existing in a
growing embryo, is transformed by the agencies acting upon it into the
succeeding phase of organization, and this into the next, until, through
ever-increasing complexities, the ultimate form is reached. Not indeed
that we can thus really explain the production of any plant or animal.
We are still in the dark respecting those mysterious properties in
virtue of which the germ, when subject to fit influences, undergoes the
special changes that begin the series of transformations. All we aim to
show, is, that given a germ possessing those particular proclivities
distinguishing the species to which it belongs, and the evolution of an
organism from it, probably depends on that multiplication of effects
which we have seen to be the cause of progress in general, so far as we
have yet traced it.

When, leaving the development of single plants and animals, we pass to
that of the Earth's flora and fauna, the course of our argument again
becomes clear and simple. Though, as was admitted in the first part of
this article, the fragmentary facts Paleontology has accumulated, do not
clearly warrant us in saying that, in the lapse of geologic time, there
have been evolved more heterogeneous organisms, and more heterogeneous
assemblages of organisms, yet we shall now see that there _must_ ever
have been a tendency towards these results. We shall find that the
production of many effects by one cause, which as already shown, has
been all along increasing the physical heterogeneity of the Earth, has
further involved an increasing heterogeneity in its flora and fauna,
individually and collectively. An illustration will make this clear.
Suppose that by a series of upheavals, occurring, as they are now known
to do, at long intervals, the East Indian Archipelago were to be, step
by step, raised into a continent, and a chain of mountains formed along
the axis of elevation. By the first of these upheavals, the plants and
animals inhabiting Borneo, Sumatra, New Guinea, and the rest, would be
subjected to slightly modified sets of conditions. The climate in
general would be altered in temperature, in humidity, and in its
periodical variations; while the local differences would be multiplied.
These modifications would affect, perhaps inappreciably, the entire
flora and fauna of the region. The change of level would produce
additional modifications: varying in different species, and also in
different members of the same species, according to their distance from
the axis of elevation. Plants, growing only on the sea-shore in special
localities, might become extinct. Others, living only in swamps of a
certain humidity, would, if they survived at all, probably undergo
visible changes of appearance. While still greater alterations would
occur in the plants gradually spreading over the lands newly raised
above the sea. The animals and insects living on these modified plants,
would themselves be in some degree modified by change of food, as well
as by change of climate; and the modification would be more marked
where, from the dwindling or disappearance of one kind of plant, an
allied kind was eaten. In the lapse of the many generations arising
before the next upheaval, the sensible or insensible alterations thus
produced in each species would become organized--there would be a more
or less complete adaptation to the new conditions. The next upheaval
would superinduce further organic changes, implying wider divergences
from the primary forms; and so repeatedly. But now let it be observed
that the revolution thus resulting would not be a substitution of a
thousand more or less modified species for the thousand original
species; but in place of the thousand original species there would arise
several thousand species, or varieties, or changed forms. Each species
being distributed over an area of some extent, and tending continually
to colonize the new area exposed, its different members would be subject
to different sets of changes. Plants and animals spreading towards the
equator would not be affected in the same way as others spreading from
it. Those spreading towards the new shores would undergo changes unlike
the changes undergone by those spreading into the mountains. Thus, each
original race of organisms, would become the root from which diverged
several races differing more or less from it and from each other; and
while some of these might subsequently disappear, probably more than one
would survive in the next geologic period: the very dispersion itself
increasing the chances of survival. Not only would there be certain
modifications thus caused by change of physical conditions and food, but
also in some cases other modifications caused by change of habit. The
fauna of each island, peopling, step by step, the newly-raised tracts,
would eventually come in contact with the faunas of other islands; and
some members of these other faunas would be unlike any creatures before
seen. Herbivores meeting with new beasts of prey, would, in some cases,
be led into modes of defence or escape differing from those previously
used; and simultaneously the beasts of prey would modify their modes of
pursuit and attack. We know that when circumstances demand it, such
changes of habit _do_ take place in animals; and we know that if the new
habits become the dominant ones, they must eventually in some degree
alter the organization. Observe now, however, a further consequence.
There must arise not simply a tendency towards the differentiation of
each race of organisms into several races; but also a tendency to the
occasional production of a somewhat higher organism. Taken in the mass
these divergent varieties which have been caused by fresh physical
conditions and habits of life, will exhibit changes quite indefinite in
kind and degree; and changes that do not necessarily constitute an
advance. Probably in most cases the modified type will be neither more
nor less heterogeneous than the original one. In some cases the habits
of life adopted being simpler than before, a less heterogeneous
structure will result: there will be a retrogradation. But it _must_ now
and then occur, that some division of a species, falling into
circumstances which give it rather more complex experiences, and demand
actions somewhat more involved, will have certain of its organs further
differentiated in proportionately small degrees,--will become slightly
more heterogeneous. Thus, in the natural course of things, there will
from time to time arise an increased heterogeneity both of the Earth's
flora and fauna, and of individual races included in them. Omitting
detailed explanations, and allowing for the qualifications which cannot
here be specified, we think it is clear that geological mutations have
all along tended to complicate the forms of life, whether regarded
separately or collectively. The same causes which have led to the
evolution of the Earth's crust from the simple into the complex, have
simultaneously led to a parallel evolution of the Life upon its surface.
In this case, as in previous ones, we see that the transformation of the
homogeneous into the heterogeneous is consequent upon the universal
principle, that every active force produces more than one change.

The deduction here drawn from the established truths of geology and the
general laws of life, gains immensely in weight on finding it to be in
harmony with an induction drawn from direct experience. Just that
divergence of many races from one race, which we inferred must have been
continually occurring during geologic time, we know to have occurred
during the pre-historic and historic periods, in man and domestic
animals. And just that multiplication of effects which we concluded must
have produced the first, we see has produced the last. Single causes, as
famine, pressure of population, war, have periodically led to further
dispersions of mankind and of dependent creatures: each such dispersion
initiating new modifications, new varieties of type. Whether all the
human races be or be not derived from one stock, philology makes it
clear that whole groups of races now easily distinguishable from each
other, were originally one race,--that the diffusion of one race into
different climates and conditions of existence, has produced many
modified forms of it. Similarly with domestic animals. Though in some
cases--as that of dogs--community of origin will perhaps be disputed,
yet in other cases--as that of the sheep or the cattle of our own
country--it will not be questioned that local differences of climate,
food, and treatment, have transformed one original breed into numerous
breeds now become so far distinct as to produce unstable hybrids.
Moreover, through the complication of effects flowing from single
causes, we here find, what we before inferred, not only an increase of
general heterogeneity, but also of special heterogeneity. While of the
divergent divisions and subdivisions of the human race many have
undergone changes not constituting an advance; while in some the type
may have degraded; in others it has become decidedly more heterogeneous.
The civilized European departs more widely from the vertebrate archetype
than does the savage. Thus, both the law and the cause of progress,
which, from lack of evidence, can be but hypothetically substantiated in
respect of the earlier forms of life on our globe, can be actually
substantiated in respect of the latest forms.[4]

If the advance of Man towards greater heterogeneity is traceable to the
production of many effects by one cause, still more clearly may the
advance of Society towards greater heterogeneity be so explained.
Consider the growth of an industrial organization. When, as must
occasionally happen, some member of a tribe displays unusual aptitude
for making an article of general use--a weapon, for instance--which was
before made by each man for himself, there arises a tendency towards the
differentiation of that member into a maker of such weapon. His
companions--warriors and hunters all of them,--severally feel the
importance of having the best weapons that can be made; and are
therefore certain to offer strong inducements to this skilled individual
to make weapons for them. He, on the other hand, having not only an
unusual faculty, but an unusual liking, for making such weapons (the
talent and the desire for any occupation being commonly associated), is
predisposed to fulfil each commission on the offer of an adequate
reward: especially as his love of distinction is also gratified and his
living facilitated. This first specialization of function, once
commenced, tends ever to become more decided. On the side of the
weapon-maker practice gives increased skill--increased superiority to
his products. On the side of his clients, cessation of practice entails
decreased skill. Thus the influences which determine this division of
labour grow stronger in both ways; and the incipient heterogeneity is,
on the average of cases, likely to become permanent for that generation
if no longer. This process not only differentiates the social mass into
two parts, the one monopolizing, or almost monopolizing, the performance
of a certain function, and the other losing the habit, and in some
measure the power, of performing that function; but it tends to initiate
other differentiations. The advance described implies the introduction
of barter,--the maker of weapons has, on each occasion, to be paid in
such other articles as he agrees to take in exchange. He will not
habitually take in exchange one kind of article, but many kinds. He does
not want mats only, or skins, or fishing-gear, but he wants all these,
and on each occasion will bargain for the particular things he most
needs. What follows? If among his fellows there exist any slight
differences of skill in the manufacture of these various things, as
there are almost sure to do, the weapon-maker will take from each one
the thing which that one excels in making: he will exchange for mats
with him whose mats are superior, and will bargain for the
fishing-gear of him who has the best. But he who has bartered away his
mats or his fishing-gear, must make other mats or fishing-gear for
himself; and in so doing must, in some degree, further develop his
aptitude. Thus it results that the small specialities of faculty
possessed by various members of the tribe, will tend to grow more
decided. And whether or not there ensue distinct differentiations of
other individuals into makers of particular articles, it is clear that
incipient differentiations take place throughout the tribe: the one
original cause produces not only the first dual effect, but a number of
secondary dual effects, like in kind, but minor in degree. This process,
of which traces may be seen among schoolboys, cannot well produce
lasting effects in an unsettled tribe; but where there grows up a fixed
and multiplying community, such differentiations become permanent, and
increase with each generation. The enhanced demand for every commodity,
intensifies the functional activity of each specialized person or class;
and this renders the specialization more definite where it already
exists, and establishes it where it is but nascent. By increasing the
pressure on the means of subsistence, a larger population again augments
these results; seeing that each person is forced more and more to
confine himself to that which he can do best, and by which he can gain
most. Presently, under these same stimuli, new occupations arise.
Competing workers, ever aiming to produce improved articles,
occasionally discover better processes or raw materials. The
substitution of bronze for stone entails on him who first makes it a
great increase of demand; so that he or his successor eventually finds
all his time occupied in making the bronze for the articles he sells,
and is obliged to depute the fashioning of these articles to others;
and, eventually, the making of bronze, thus differentiated from a
pre-existing occupation, becomes an occupation by itself. But now mark
the ramified changes which follow this change. Bronze presently
replaces stone, not only in the articles it was first used for, but in
many others--in arms, tools, and utensils of various kinds: and so
affects the manufacture of them. Further, it affects the processes which
these utensils subserve, and the resulting products,--modifies
buildings, carvings, personal decorations. Yet again, it sets going
manufactures which were before impossible, from lack of a material fit
for the requisite implements. And all these changes react on the
people--increase their manipulative skill, their intelligence, their
comfort,--refine their habits and tastes. Thus the evolution of a
homogeneous society into a heterogeneous one, is clearly consequent on
the general principle, that many effects are produced by one cause.

Space permitting, we might show how the localization o£ special
industries in special parts of a kingdom, as well as the minute
subdivision of labour in the making of each commodity, are similarly
determined. Or, turning to a somewhat different order of illustrations,
we might dwell on the multitudinous changes--material, intellectual,
moral,--caused by printing; or the further extensive series of changes
wrought by gunpowder. But leaving the intermediate phases of social
development, let us take a few illustrations from its most recent and
its passing phases. To trace the effects of steam-power, in its manifold
applications to mining, navigation, and manufactures of all kinds, would
carry us into unmanageable detail. Let us confine ourselves to the
latest embodiment of steam power--the locomotive engine. This, as the
proximate cause of our railway system, has changed the face of the
country, the course of trade, and the habits of the people. Consider,
first, the complicated sets of changes that precede the making of every
railway--the provisional arrangements, the meetings, the registration,
the trial section, the parliamentary survey, the lithographed plans, the
books of reference, the local deposits and notices, the application to
Parliament, the passing Standing Orders Committee, the first, second,
and third readings: each of which brief heads indicates a multiplicity
of transactions, and the extra development of sundry occupations--as
those of engineers, surveyors, lithographers, parliamentary agents,
share-brokers; and the creation of sundry others--as those of
traffic-takers, reference-takers. Consider, next, the yet more marked
changes implied in railway construction--the cuttings, embankings,
tunnellings, diversions of roads; the building of bridges and stations,
the laying down of ballast, sleepers, and rails; the making of engines,
tenders, carriages, and waggons: which processes, acting on numerous
trades, increase the importation of timber, the quarrying of stone, the
manufacture of iron, the mining of coal, the burning of bricks;
institute a variety of special manufactures weekly advertised in the
_Railway Times_; and, finally, open the way to sundry new occupations,
as those of drivers, stokers, cleaners, plate-layers, &c., &c. And then
consider the changes, still more numerous and involved, which railways
in action produce on the community at large. Business agencies are
established where previously they would not have paid; goods are
obtained from remote wholesale houses instead of near retail ones; and
commodities are used which distance once rendered inaccessible. Again,
the diminished cost of carriage tends to specialize more than ever the
industries of different districts--to confine each manufacture to the
parts in which, from local advantages, it can be best carried on.
Further, the fall in freights, facilitating distribution, equalizes
prices, and also, on the average, lowers prices: thus bringing divers
articles within the means of those before unable to buy them, and so
increasing their comforts and improving their habits. At the same time
the practice of travelling is immensely extended. People who never
before dreamed of it, take trips to the sea; visit their distant
relations; make tours; and so we are benefited in body, feelings, and
ideas. The more prompt transmission of letters and of news produces
other marked changes--makes the pulse of the nation faster. Once more,
there arises a wide dissemination of cheap literature through railway
book-stalls, and of advertisements in railway carriages: both of them
aiding ulterior progress. And the countless changes here briefly
indicated are consequent on the invention of the locomotive engine. The
social organism has been rendered more heterogeneous in virtue of the
many new occupations introduced, and the many old ones further
specialized; prices of nearly all things in every place have been
altered; each trader has modified his way of doing business; and every
person has been affected in his actions, thoughts, emotions.

Illustrations to the same effect might be indefinitely accumulated, but
they are needless. The only further fact demanding notice, is, that we
here see still more clearly the truth before pointed out, that in
proportion as the area on which any force expends itself becomes
heterogeneous, the results are in a yet higher degree multiplied in
number and kind. While among the simple tribes to whom it was first
known, caoutchouc caused but few changes, among ourselves the changes
have been so many and varied that the history of them occupies a
volume.[5] Upon the small, homogeneous community inhabiting one of the
Hebrides, the electric telegraph would produce, were it used, scarcely
any results; but in England the results it produces are multitudinous.
The comparatively simple organization under which our ancestors lived
five centuries ago, could have undergone but few modifications from an
event like the recent one at Canton; but now, the legislative decision
respecting it sets up many hundreds of complex modifications, each of
which will be the parent of numerous future ones.

Space permitting, we could willingly have pursued the argument in
relation to all the subtler results of civilization. As before we showed
that the law of progress to which the organic and inorganic worlds
conform, is also conformed to by Language, the plastic arts, Music, &c.;
so might we here show that the cause which we have hitherto found to
determine progress holds in these cases also. Instances might be given
proving how, in Science, an advance of one division presently advances
other divisions--how Astronomy has been immensely forwarded by
discoveries in Optics, while other optical discoveries have initiated
Microscopic Anatomy, and greatly aided the growth of Physiology--how
Chemistry has indirectly increased our knowledge of Electricity,
Magnetism, Biology, Geology--how Electricity has reacted on Chemistry
and Magnetism, and has developed our views of Light and Heat. In
Literature the same truth might be exhibited in the manifold effects of
the primitive mystery-play, as originating the modern drama, which has
variously branched; or in the still multiplying forms of periodical
literature which have descended from the first newspaper, and which have
severally acted and reacted on other forms of literature and on each
other. The influence which a new school of Painting--as that of the
pre-Raphaelites--exercises upon other schools; the hints which all kinds
of pictorial art are deriving from Photography; the complex results of
new critical doctrines, as those of Mr. Ruskin, might severally be dwelt
upon as displaying the like multiplication of effects.

But we venture to think our case is already made out. The imperfections
of statement which brevity has necessitated, do not, we believe,
invalidate the propositions laid down. The qualifications here and there
demanded would not, if made, affect the inferences. Though, in tracing
the genesis of progress, we have frequently spoken of complex causes as
if they were simple ones; it still remains true that such causes are far
less complex than their results. Detailed criticisms do not affect our
main position. Endless facts go to show that every kind of progress is
from the homogeneous to the heterogeneous; and that it is so because
each change is followed by many changes. And it is significant that
where the facts are most accessible and abundant, there these truths are
most manifest.

However, to avoid committing ourselves to more than is yet proved, we
must be content with saying that such are the law and the cause of all
progress that is known to us. Should the Nebular Hypothesis ever be
established, then it will become manifest that the Universe at large,
like every organism, was once homogeneous; that as a whole, and in every
detail, it has unceasingly advanced towards greater heterogeneity. It
will be seen that as in each event of to-day, so from the beginning, the
decomposition of every expended force into several forces has been
perpetually producing a higher complication; that the increase of
heterogeneity so brought about is still going on and must continue to go
on; and that thus progress is not an accident, not a thing within human
control, but a beneficent necessity.

       *       *       *       *       *

A few words must be added on the ontological bearings of our argument.
Probably not a few will conclude that here is an attempted solution of
the great questions with which Philosophy in all ages has perplexed
itself. Let none thus deceive themselves. After all that has been said,
the ultimate mystery remains just as it was. The explanation of that
which is explicable, does but bring out into greater clearness the
inexplicableness of that which remains behind. Little as it seems to do
so, fearless inquiry tends continually to give a firmer basis to all
true Religion. The timid sectarian, obliged to abandon one by one the
superstitions bequeathed to him, and daily finding his cherished beliefs
more and more shaken, secretly fears that all things may some day be
explained; and has a corresponding dread of Science: thus evincing the
profoundest of all infidelity--the fear lest the truth be bad. On the
other hand, the sincere man of science, content to follow wherever the
evidence leads him, becomes by each new inquiry more profoundly
convinced that the Universe is an insoluble problem. Alike in the
external and the internal worlds, he sees himself in the midst of
ceaseless changes, of which he can discover neither beginning nor end.
If, tracing back the evolution of things, he allows himself to entertain
the hypothesis that all matter once existed in a diffused form, he finds
it impossible to conceive how this came to be so; and equally, if he
speculates on the future, he can assign no limit to the grand succession
of phenomena ever unfolding themselves before him. Similarly, if he
looks inward, he perceives that both terminations of the thread of
consciousness are beyond his grasp: he cannot remember when or how
consciousness commenced, and he cannot examine the consciousness at any
moment existing; for only a state of consciousness which is already past
can become the object of thought, and never one which is passing. When,
again, he turns from the succession of phenomena, external or internal,
to their essential nature, he is equally at fault. Though he may succeed
in resolving all properties of objects into manifestations of force, he
is not thereby enabled to conceive what force is; but finds, on the
contrary, that the more he thinks about it, the more he is baffled.
Similarly, though analysis of mental actions may finally bring him down
to sensations as the original materials out of which all thought is
woven, he is none the forwarder; for he cannot in the least comprehend
sensation. Inward and outward things he thus discovers to be alike
inscrutable in their ultimate genesis and nature. He sees that the
Materialist and Spiritualist controversy is a mere war of words; the
disputants being equally absurd--each believing he understands that
which it is impossible for any man to understand. In all directions his
investigations eventually bring him face to face with the unknowable;
and he ever more clearly perceives it to be the unknowable. He learns at
once the greatness and the littleness of human intellect--its power in
dealing with all that comes within the range of experience; its
impotence in dealing with all that transcends experience. He feels more
vividly than any others can feel, the utter incomprehensibleness of the
simplest fact, considered in itself. He alone truly _sees_ that absolute
knowledge is impossible. He alone _knows_ that under all things there
lies an impenetrable mystery.

FOOTNOTES:

[Footnote 2: Since this was written (in 1857) the advance of
paleontological discovery, especially in America, has shown
conclusively, in respect of certain groups of vertebrates, that higher
types have arisen by modifications of lower; so that, in common with
others, Prof. Huxley, to whom the above allusion is made, now admits, or
rather asserts, biological progression, and, by implication, that there
have arisen more heterogeneous organic forms and a more heterogeneous
assemblage of organic forms.]

[Footnote 3: For detailed proof of these assertions see essay on
"Manners and Fashion."]

[Footnote 4: The argument concerning organic evolution contained in this
paragraph and the one preceding it, stands verbatim as it did when first
published in the _Westminster Review_ for April, 1857. I have thus left
it without the alteration of a word that it may show the view I then
held concerning the origin of species. The sole cause recognized is that
of direct adaptation of constitution to conditions consequent on
inheritance of the modifications of structure resulting from use and
disuse. There is no recognition of that further cause disclosed in Mr.
Darwin's work, published two and a half years later--the indirect
adaptation resulting from the natural selection of favourable
variations. The multiplication of effects is, however, equally
illustrated in whatever way the adaptation to changing conditions is
effected, or if it is effected in both ways, as I hold. I may add that
there is indicated the view that the succession of organic forms is not
serial but proceeds by perpetual divergence and re-divergence--that
there has been a continual "divergence of many races from one race":
each species being a "root" from which several other species branch out;
and the growth of a tree being thus the implied symbol.]

[Footnote 5: "Personal Narrative of the Origin of the Caoutchouc, or
India-Rubber Manufacture in England." By Thomas Hancock.]




TRANSCENDENTAL PHYSIOLOGY.

    [_First published in_ The National Review _for October,_ 1857_,
    under the title of "The Ultimate Laws of Physiology". The title
    "Transcendental Physiology", which the editor did not approve, was
    restored when the essay was re-published with others in_ 1857.]


The title Transcendental Anatomy is used to distinguish that division of
biological science which treats, not of the structures of individual
organisms considered separately, but of the general principles of
structure common to vast and varied groups of organisms,--the unity of
plan discernible throughout multitudinous species, genera, and orders,
which differ widely in appearance. And here, under the head of
Transcendental Physiology, we purpose putting together sundry laws of
development and function which hold not of particular kinds or classes
of organisms, but of all organisms: laws, some of which have not, we
believe, been hitherto enunciated.

By way of unobtrusively introducing the general reader to biological
truths of this class, let us begin by noticing one or two with which he
is familiar. Take first, the relation between the activity of an organ
and its growth. This is a universal relation. It holds, not only of a
bone, a muscle, a nerve, an organ of sense, a mental faculty; but of
every gland, every viscus, every element of the body. It is seen, not in
man only, but in each animal which affords us adequate opportunity of
tracing it. Always providing that the performance of function is not so
excessive as to produce disorder, or to exceed the repairing powers
either of the system at large or of the particular agencies by which
nutriment is brought to the organ,--always providing this, it is a law
of organized bodies that, other things equal, development varies as
function. On this law are based all maxims and methods of right
education, intellectual, moral, and physical; and when statesmen are
wise enough to see it, this law will be found to underlie all right
legislation.

Another truth co-extensive with the organic world, is that of hereditary
transmission. It is not, as commonly supposed, that hereditary
transmission is exemplified merely in re-appearance of the family
peculiarities displayed by immediate or remote progenitors. Nor does the
law of hereditary transmission comprehend only such more general facts
as that modified plants or animals become the parents of permanent
varieties; and that new kinds of potatoes, new breeds of sheep, new
races of men, have been thus originated. These are but minor
exemplifications of the law. Understood in its entirety, the law is that
each plant or animal produces others of like kind with itself: the
likeness of kind consisting not so much in the repetition of individual
traits as in the assumption of the same general structure. This truth
has been made by daily illustration so familiar as nearly to have lost
its significance. That wheat produces wheat,--that existing oxen are
descended from ancestral oxen,--that every unfolding organism ultimately
takes the form of the class, order, genus, and species from which it
sprang; is a fact which, by force of repetition, has assumed in our
minds the character of a necessity. It is in this, however, that the law
of hereditary transmission is principally displayed; the phenomena
commonly named as exemplifying it being quite subordinate
manifestations. And the law, as thus understood, is universal. Not
forgetting the apparent, but only apparent, exceptions presented by the
strange class of phenomena known as "alternate generation," the truth
that like produces like is common to all types of organisms.

Let us take next a universal physiological law of a less conspicuous
kind. To the ordinary observer, it seems that the multiplication of
organisms proceeds in various ways. He sees that the young of the higher
animals when born resemble their parents; that birds lay eggs, which
they foster and hatch; that fish deposit spawn and leave it. Among
plants, he finds that while in some cases new individuals grow from
seeds only, in other cases they also grow from tubers; that by certain
plants layers are sent out, take root, and develop new individuals; and
that many plants can be reproduced from cuttings. Further, in the mould
that quickly covers stale food, and the infusoria that soon swarm in
water exposed to air and light, he sees a mode of generation which,
seeming inexplicable, he is apt to consider "spontaneous." The reader of
popular science thinks the modes of reproduction still more various. He
learns that whole tribes of creatures multiply by gemmation--by a
development from the body of the parent of buds which, after unfolding
into the parental form, separate and lead independent lives. Concerning
microscopic forms of both animal and vegetal life, he reads that the
ordinary mode of multiplication is by spontaneous fission--a splitting
up of the original individual into two or more individuals, which by and
by severally repeat the process. Still more remarkable are the cases in
which, as in the _Aphis_, an egg gives rise to an imperfect female, from
which other imperfect females are born viviparously, grow, and in their
turns bear other imperfect females; and so on for eight, ten, or more
generations, until finally, perfect males and females are viviparously
produced. But now under all these, and many more, modified modes of
multiplication, the physiologist finds complete uniformity. The
starting-point, not only of every higher animal or plant, but of every
clan of organisms which by fission or gemmation have sprung from a
single organism, is always a spore, seed, or ovum. The millions of
infusoria or of aphides which, by sub-division or gemmation, have
proceeded from one individual; the countless plants which have been
successively propagated from one original plant by cuttings or tubers;
are, in common with the highest creature, primarily descended from a
fertilized germ. And in all cases--in the humblest alga as in the oak,
in the protozoon as in the mammal--this fertilized germ results from the
union of the contents of two cells. Whether, as among the lowest forms
of life, these two cells are seemingly identical in nature; or whether,
as among higher forms, they are distinguishable into sperm-cell and
germ-cell; it remains throughout true that from their combination
results the mass out of which is evolved a new organism or new series of
organisms. That this law is without exception we are not prepared to
say; for in the case of the _Aphis_ certain experiments are thought to
imply that under special conditions the descendants of an original
individual may continue multiplying for ever, without further
fecundation. But we know of no case where it _actually is_ so; for
although there are certain plants of which the seeds have never been
seen, it is more probable that our observations are in fault than that
these plants are exceptions. And until we find undoubted exceptions, the
above-stated induction must stand. Here, then, we have another of the
truths of Transcendental Physiology: a truth which, so far as we know,
_transcends_ all distinctions of genus, order, class, kingdom, and
applies to every living thing.

Yet another generalization of like universality expresses the process of
organic development. To the ordinary observer there seems no unity in
this. No obvious parallelism exists between the unfolding of a plant and
the unfolding of an animal. There is no manifest similarity between the
development of a mammal, which proceeds without break from its first to
its last stage, and that of an insect, which is divided into
strongly-marked stages--egg, larva, pupa, imago. Nevertheless it is now
an established fact, that all organisms are evolved after one general
method. At the outset the germ of every plant or animal is relatively
homogeneous; and advance towards maturity is advance towards greater
heterogeneity. Each organized thing commences as an almost structureless
mass, and reaches its ultimate complexity by the establishment of
distinctions upon distinctions,--by the divergence of tissues from
tissues and organs from organs. Here, then, we have yet another
biological law of transcendent generality.

Having thus recognized the scope of Transcendental Physiology as
presented in its leading truths, we are prepared for the considerations
that are to follow.

       *       *       *       *       *

And first, returning to the last of the great generalizations above
given, let us inquire more nearly how this change from the homogeneous
to the heterogeneous is carried on. Usually it is said to result from
successive differentiations. This, however, cannot be considered a
complete account of the process. During the evolution of an organism
there occur, not only separations of parts, but coalescences of parts.
There is not only segregation, but aggregation. The heart, at first a
simple pulsating blood-vessel, by and by twists upon itself and becomes
integrated. The bile-cells constituting the rudimentary liver, do not
merely diverge from the surface of the intestine in which they at first
form a simple layer; but they simultaneously consolidate into a definite
organ. And the gradual concentration seen in these and other cases is a
part of the developmental process--a part which, though more or less
recognized by Milne-Edwards and others, does not seem to have been
included as an essential element in it.

This progressive integration, manifest alike when tracing up the several
stages passed through by every embryo, and when ascending from the lower
organic forms to the higher, may be most conveniently studied under
several heads. Let us consider first what may be called _longitudinal
integration_.

The lower _Annulosa_--worms, myriapods, &c.--are characterized by the
great numbers of segments of which they respectively consist, reaching
in some cases to several hundreds; but as we advance to the higher
_Annulosa_--centipedes, crustaceans, insects, spiders,--we find these
numbers greatly reduced, down to twenty-two, thirteen, and even fewer;
and accompanying this there is a shortening or integration of the whole
body, reaching its extreme in crabs and spiders. Similarly with the
development of an individual crustacean or insect. The thorax of a
lobster, which, in the adult, forms, with the head, one compact box
containing the viscera, is made up by the union of a number of segments
which in the embryo were separable. The thirteen distinct divisions seen
in the body of a caterpillar, become further integrated in the
butterfly: several segments are consolidated to form the thorax, and the
abdominal segments are more aggregated than they originally were. The
like truth is seen when we pass to the internal organs. In the lower
annulose forms, and in the larvæ of the higher ones, the alimentary
canal consists either of a tube that is uniform from end to end, or else
bulges into a succession of stomachs, one to each segment; but in the
developed forms there is a single well-defined stomach. In the nervous,
vascular, and respiratory systems a parallel concentration may be
traced. Again, in the development of the _Vertebrata_ we have sundry
examples of longitudinal integration. The coalescence of several
segmental groups of bones to form the skull is one instance of it. It is
further illustrated in the _os coccygis_, which results from the fusion
of a number of caudal vertebræ. And in the consolidation of the sacral
vertebræ of a bird it is also well exemplified.

That which we may distinguish as _transverse integration_, is well
illustrated among the _Annulosa_ in the development of the nervous
system. Leaving out those simple forms which do not present distinct
ganglia, it is to be observed that the lower annulose animals, in common
with the larvæ of the higher, are severally characterized by a double
chain of ganglia running from end to end of the body; while in the more
advanced annulose animals this double chain becomes a single chain. Mr.
Newport has described the course of this concentration in insects; and
by Rathke it has been traced in crustaceans. In the early stages of the
_Astacus fluviatilis_, or common cray-fish, there is a pair of separate
ganglia to each ring. Of the fourteen pairs belonging to the head and
thorax, the three pairs in advance of the mouth consolidate into one
mass to form the brain, or cephalic ganglion. Meanwhile out of the
remainder, the first six pairs severally unite in the median line, while
the rest remain more or less separate. Of these six double ganglia thus
formed, the anterior four coalesce into one mass; the remaining two
coalesce into another mass; and then these two masses coalesce into one.
Here we see longitudinal and transverse integration going on
simultaneously; and in the highest crustaceans they are both carried
still further. The _Vertebrata_ exhibit this transverse integration in
the development of the generative system. The lowest of the
mammalia--the _Monotremata_--in common with birds, have oviducts which
towards their lower extremities are dilated into cavities severally
performing in an imperfect way the function of a uterus. "In the
_Marsupialia_, there is a closer approximation of the two lateral sets
of organs on the median line; for the oviducts converge towards one
another and meet (without coalescing) on the median line; so that their
uterine dilatations are in contact with each other, forming a true
'double uterus.' ... As we ascend the series of 'placental' mammals, we
find the lateral coalescence becoming gradually more and more
complete.... In many of the _Rodentia_, the uterus still remains
completely divided into two lateral halves; whilst in others, these
coalesce at their lower portion, forming a rudiment of the true 'body'
of the uterus in the Human subject. This part increases at the expense
of the lateral 'cornua' in the higher Herbivora and Carnivora; but even
in the lower Quadrumana, the uterus is somewhat cleft at its
summit."[6] And this process of transverse integration, which is still
more striking when observed in its details, is accompanied by parallel
though less important changes in the opposite sex. Once more; in the
increasing commissural connexion of the cerebral hemispheres, which,
though separate in the lower vertebrata, become gradually more united in
the higher, we have another instance. And further ones of a different
order, but of like general implication, are supplied by the vascular
system.

Now it seems to us that the various kinds of integration here
exemplified, which are commonly set down as so many independent
phenomena, ought to be generalized, and included in the formula
describing the process of development. The fact that in an adult crab,
many pairs of ganglia originally separate have become fused into a
single mass, is a fact only second in significance to the
differentiation of its alimentary canal into stomach and intestine. That
in the higher _Annulosa_, a single heart replaces the string of
rudimentary hearts constituting the dorsal blood-vessel in the lower
_Annulosa_, (reaching in one species to the number of one hundred and
sixty), is a truth as much needing to be comprised in the history of
evolution, as is the formation of a respiratory surface by a branched
expansion of the skin. A right conception of the genesis of a vertebral
column, includes not only the differentiations from which result the
_chorda dorsalis_ and the vertebral segments imbedded in it; but quite
as much it includes the coalescence of numerous vertebral processes with
their respective vertebral bodies. The changes in virtue of which
several things become one, demand recognition equally with those in
virtue of which one thing becomes several. Evidently, then, the current
statement which ascribes the developmental progress to differentiations
alone, is incomplete. Adequately to express the facts, we must say
that the transition from the homogeneous to the heterogeneous is carried
on by differentiations and accompanying integrations.

It may not be amiss here to ask--What is the meaning of these
integrations? The evidence seems to show that they are in some way
dependent on community of function. The eight segments which coalesce to
make the head of a centipede, jointly protect the cephalic ganglion, and
afford a solid fulcrum for the jaws, &c. The many bones which unite to
form a vertebral skull have like uses. In the consolidation of the
several pieces which constitute a mammalian pelvis, and in the
anchylosis of from ten to nineteen vertebræ in the sacrum of a bird, we
have kindred instances of the integration of parts which transfer the
weight of the body to the legs. The more or less extensive fusion of the
tibia with the fibula and the radius with the ulna in the ungulated
mammals, whose habits require only partial rotations of the limbs, is a
fact of like meaning. And all the instances lately given--the
concentration of ganglia, the replacement of many pulsating blood-sacs
by fewer and finally by one, the fusion of two uteri into a single
uterus--have the same implication. Whether, as in some cases, the
integration is merely a consequence of the growth which eventually
brings into contact adjacent parts performing similar duties; or
whether, as in other cases, there is an actual approximation of these
parts before their union; or whether, as in yet other cases, the
integration is of that indirect kind which arises when, out of a number
of like organs, one, or a group, discharges an ever-increasing share of
the common function, and so grows while the rest dwindle and
disappear;--the general fact remains the same, that there is a tendency
to the unification of parts having similar duties.

The tendency, however, acts under limiting conditions; and recognition
of them will explain some apparent exceptions. In the human foetus, as
in the lower vertebrata, the eyes are placed one on each side of the
head. During evolution they become relatively nearer, and at birth are
in front; though they are still, in the European infant as in the adult
Mongol, proportionately further apart than they afterwards become. But
this approximation shows no signs of further increase. Two reasons
suggest themselves. One is that the two eyes have not quite the same
function, since they are directed to slightly-different aspects of each
object looked at; and, since the resulting binocular vision has an
advantage over monocular vision, there results a check upon further
approach towards identity of function and unity of structure. The other
reason is that the interposed structures do not admit of any nearer
approach. For the orbits of the eyes to be brought closer together,
would imply a decrease in the olfactory chambers; and as these are
probably not larger than is demanded by their present functional
activity, no decrease can take place. Again, if we trace up the external
organs of smell through fishes,[7] reptiles, ungulate mammals and
unguiculate mammals, to man, we perceive a general tendency to
coalescence in the median line; and on comparing the savage with the
civilized, or the infant with the adult, we see this approach of the
nostrils carried furthest in the most perfect of the species. But since
the septum which divides them has the function both of an evaporating
surface for the lachrymal secretion, and of a ramifying surface for a
nerve ancillary to that of smell, it does not disappear entirely: the
integration remains incomplete. These and other like instances do not
however militate against the hypothesis. They merely show that the
tendency is sometimes antagonized by other tendencies. Bearing in mind
which qualification, we may say, that as differentiation of parts is
connected with difference of function, so there appears to be a
connexion between integration of parts and sameness of function.

       *       *       *       *       *

Closely related to the general truth that the evolution of all organisms
is carried on by combined differentiations and integrations, is another
general truth, which physiologists appear not to have recognized. When
we look at the organic world as a whole, we may observe that, on passing
from lower to higher forms, we pass to forms which are not only
characterized by a greater differentiation of parts, but are at the same
time more completely differentiated from the surrounding medium. This
truth may be contemplated under various aspects.

In the first place it is illustrated in _structure_. The advance from
the homogeneous to the heterogeneous itself involves an increasing
distinction from the inorganic world. In the lowest _Protozoa_, as some
of the Rhizopods, we have a homogeneity approaching to that of air,
water, or earth; and the ascent to organisms of greater and greater
complexity of structure, is an ascent to organisms which are in that
respect more strongly contrasted with the relatively structureless
masses in the environment.

In _form_ again we see the same truth. A general characteristic of
inorganic matter is its indefiniteness of form, and this is also a
characteristic of the lower organisms, as compared with the higher.
Speaking generally, plants are less definite than animals, both in shape
and size--admit of greater modifications from variations of position and
nutrition. Among animals, the _Amoeba_ and its allies are not only
almost structureless, but are amorphous; and the irregular form is
constantly changing. Of the organisms resulting from the aggregation of
amoeba-like creatures, we find that while some assume a certain
definiteness of form, in their compound shells at least, others, as the
Sponges, are irregular. In the Zoophytes and in the _Polyzoa_, we see
compound organisms, most of which have modes of growth not more
determinate than those of plants. But among the higher animals, we find
not only that the mature shape of each species is quite definite, but
that the individuals of each species differ very little in size.

A parallel increase of contrast is seen in _chemical composition_. With
but few exceptions, and those only partial ones, the lowest animal and
vegetal forms are inhabitants of the water; and water is almost their
sole constituent. Dessicated _Protophyta_ and _Protozoa_ shrink into
mere dust; and among the acalephes we find but a few grains of solid
matter to a pound of water. The higher aquatic plants, in common with
the higher aquatic animals, possessing as they do much greater tenacity
of substance, also contain a greater proportion of the organic elements;
and so are chemically more unlike their medium. And when we pass to the
superior classes of organisms--land plants and land animals--we find
that, chemically considered, they have little in common either with the
earth on which they stand or the air which surrounds them.

In _specific gravity_, too, we may note the like. The very simplest
forms, in common with the spores and gemmules of the higher ones, are as
nearly as may be of the same specific gravity as the water in which they
float; and though it cannot be said that among aquatic creatures
superior specific gravity is a standard of general superiority, yet we
may fairly say that the superior orders of them, when divested of the
appliances by which their specific gravity is regulated, differ more
from water in their relative weights than do the lower. In terrestrial
organisms, the contrast becomes extremely marked. Trees and plants, in
common with insects, reptiles, mammals, birds, are all of a specific
gravity considerably less than the earth and immensely greater than the
air.

We see the law similarly fulfilled in respect of _temperature_. Plants
generate but an extremely small quantity of heat, which is to be
detected only by delicate experiments; and practically they may be
considered as being in this respect like their environment. Aquatic
animals rise very little above the surrounding water in temperature:
that of the invertebrata being mostly less than a degree above it, and
that of fishes not exceeding it by more than two or three degrees, save
in the case of some large red-blooded fishes, as the tunny, which exceed
it by nearly ten degrees. Among insects, the range is from two to ten
degrees above that of the air: the excess varying according to their
activity. The heat of reptiles is from four to fifteen degrees more than
that of their medium. While mammals and birds maintain a heat which
continues almost unaffected by external variations, and is often greater
than that of the air by seventy, eighty, ninety, and even a hundred
degrees.

Once more, in greater _self-mobility_ a progressive differentiation is
traceable. Dead matter is inert: some form of independent motion is our
most general test of life. Passing over the indefinite border-land
between the animal and vegetable kingdoms, we may roughly class plants
as organisms which, while they exhibit the kind of motion implied in
growth, are not only without locomotive power, but in nearly all cases
are without the power of moving their parts in relation to one another;
and thus are less differentiated from the inorganic world than animals.
Though in those microscopic _Protophyta_ and _Protozoa_ inhabiting the
water--the spores of algæ, the gemmules of sponges, and the infusoria
generally--we see locomotion produced by ciliary action; yet this
locomotion, while rapid relatively to their sizes, is absolutely slow.
Of the _Coelenterata_, a great part are either permanently rooted or
habitually stationary, and so have scarcely any self-mobility but that
implied in the relative movements of parts; while the rest, of which the
common jelly-fish serves as a sample, have mostly but little ability to
move themselves through the water. Among the higher aquatic
_Invertebrata_,--cuttle-fishes and lobsters, for instance,--there is a
very considerable power of locomotion; and the aquatic _Vertebrata_ are,
considered as a class, much more active in their movements than the
other inhabitants of the water. But it is only when we come to
air-breathing creatures that we find the vital characteristic of
self-mobility manifested in the highest degree. Flying insects, mammals,
birds, travel with velocities far exceeding those attained by any of the
lower classes of animals; and so are more strongly contrasted with their
inert environments.

Thus, on contemplating the various grades of organisms in their
ascending order, we find them more and more distinguished from their
inanimate media in _structure_, in _form_, in _chemical composition_, in
_specific gravity_, in _temperature_, in _self-mobility_. It is true
that this generalization does not hold with regularity. Organisms which
are in some respects the most strongly contrasted with the inorganic
world, are in other respects less contrasted than inferior organisms. As
a class, mammals are higher than birds; and yet they are of lower
temperature, and have smaller powers of locomotion. The stationary
oyster is of higher organization than the free-swimming medusa; and the
cold-blooded and less heterogeneous fish is quicker in its movements
than the warm-blooded and more heterogeneous sloth. But the admission
that the several aspects under which this increasing contrast shows
itself bear variable ratios to one another, does not negative the
general truth enunciated. Looking at the facts in the mass, it cannot be
denied that the successively higher groups of organisms are severally
characterized, not only by greater differentiation of parts, but also by
greater differentiation from the surrounding medium in sundry other
physical attributes. It would seem that this peculiarity has some
necessary connexion with superior vital manifestations. One of those
lowly gelatinous forms which are some of them so transparent and
colourless as to be with difficulty distinguished from the water they
float in, is not more like its medium in chemical, mechanical, optical,
thermal, and other properties, than it is in the passivity with which it
submits to all the actions brought to bear on it; while the mammal does
not more widely differ from inanimate things in these properties than it
does in the activity with which it meets surrounding changes by
compensating changes in itself. Between these two extremes, we see a
tolerably constant ratio between these two kinds of contrast. In
proportion as an organism is physically like its environment it remains
a passive partaker of the changes going on in its environment; while in
proportion as it is endowed with powers of counteracting such changes,
it exhibits greater unlikeness to its environment.

       *       *       *       *       *

Thus far we have proceeded inductively, in conformity with established
usage; but it seems to us that much may be done in this and other
departments of biologic inquiry by pursuing the deductive method. The
generalizations at present constituting the science of physiology, both
general and special, have been reached _a posteriori_; but certain
fundamental data have now been discovered, starting from which we may
reason our way _a priori_, not only to some of the truths that have been
ascertained by observation and experiment, but also to some others. The
possibility of such _a priori_ conclusions will be at once recognized on
considering some familiar cases.

Chemists have shown that a necessary condition to vital activity in
animals is oxidation of certain matters contained in the body either as
components or as waste products. The oxygen requisite for this oxidation
is contained in the surrounding medium--air or water, as the case may
be. If the organism be minute, mere contact of its external surface with
the oxygenated medium achieves the requisite oxidation; but if the
organism is bulky, and so exposes a surface which is small in
proportion to its mass, any considerable oxidation cannot be thus
achieved. One of two things is therefore implied. Either this bulky
organism, receiving no oxygen but that absorbed through its integument,
must possess but little vital activity; or else, if it possesses much
vital activity, there must be some extensive ramified surface, internal
or external, through which adequate aeration may take place--a
respiratory apparatus. That is to say, lungs, or gills, or branchiæ, or
their equivalents, are predicable _a priori_ as possessed by all active
creatures of any size.

Similarly with respect to nutriment. There are _entozoa_ which, living
in the insides of other animals, and being constantly bathed by
nutritive fluids, absorb a sufficiency through their outer surfaces; and
so have no need of stomachs, and do not possess them. But all other
animals, inhabiting media that are not in themselves nutritive, but only
contain masses of food here and there, must have appliances by which
these masses of food may be utilized. Evidently mere external contact of
a solid organism with a solid portion of nutriment, could not result in
the absorption of it in any moderate time, if at all. To effect
absorption, there must be both a solvent or macerating action, and an
extended surface fit for containing and imbibing the dissolved products:
there must be a digestive cavity. Thus, given the ordinary conditions of
animal life, and the possession of stomachs by all creatures living
under these conditions may be deductively known.

Carrying out the train of reasoning still further, we may infer the
existence of a vascular system or something equivalent to it, in all
creatures of any size and activity. In a comparatively small inert
animal, such as the hydra, which consists of little more than a sac
having a double wall--an outer layer of cells forming the skin, and an
inner layer forming the digestive and absorbent surface--there is no
need for a special apparatus to diffuse through the body the aliment
taken up; for the body is little more than a wrapper to the food it
encloses. But where the bulk is considerable, or where the activity is
such as to involve much waste and repair, or where both these
characteristics exist, there is a necessity for a system of
blood-vessels. It is not enough that there be adequately extensive
surfaces for absorption and aeration; for in the absence of any means of
conveyance, the absorbed elements can be of little or no use to the
organism at large. Evidently there must be channels of communication.
When, as in the _Medusæ_, we find these channels of communication
consisting simply of branched canals opening out of the stomach and
spreading through the disk, we may know, _a priori_, that such creatures
are comparatively inactive; seeing that the nutritive liquid thus
partially distributed throughout their bodies is crude and dilute, and
that there is no efficient appliance for keeping it in motion.
Conversely, when we meet with a creature of considerable size which
displays much vivacity, we may know, _a priori_, that it must have an
apparatus for the unceasing supply of concentrated nutriment, and of
oxygen, to every organ--a pulsating vascular system.

It is manifest, then, that setting out from certain known fundamental
conditions to vital activity, we may deduce from them sundry of the
chief characteristics of organized bodies. Doubtless these known
fundamental conditions have been inductively established. But what we
wish to show is that, given these inductively-established primary facts
in physiology, we may with safety draw certain general deductions from
them. And, indeed, the legitimacy of such deductions, though not
formally acknowledged, is practically recognized in the convictions of
every physiologist, as may be readily proved. Thus, were a physiologist
to find a creature exhibiting complex and variously co-ordinated
movements, and yet having no nervous system; he would be less astonished
at the breach of his empirical generalization that all such creatures
have nervous systems, than at the disproof of his unconscious deduction
that all creatures exhibiting complex and variously co-ordinated
movements must have an "internuncial" apparatus by which the
co-ordination may be effected. Or were he to find a creature having
blood rapidly circulated and rapidly aerated, but yet showing a low
temperature, the proof so afforded that active change of matter is not,
as he had inferred from chemical data, the cause of animal heat, would
stagger him more than would the exception to a constantly-observed
relation. Clearly, then, the _a priori_ method already plays a part in
physiological reasoning. If not ostensibly employed as a means of
reaching new truths, it is at least privately appealed to for
confirmation of truths reached _a posteriori_.

But the illustrations above given go far to show, that it may to a
considerable extent be safely used as an independent instrument of
research. The necessities for a nutritive system, a respiratory system,
and a vascular system, in all animals of size and vivacity, seem to us
legitimately inferable from the conditions to continued vital activity.
Given the physical and chemical data, and these structural peculiarities
may be deduced with as much certainty as may the hollowness of an iron
ball from its power of floating in water.

It is not, of course, asserted that the more _special_ physiological
truths can be deductively reached. The argument by no means implies
this. Legitimate deduction presupposes adequate data; and in respect to
the _special_ phenomena of organic growth, structure, and function,
adequate data are unattainable, and will probably ever remain so. It is
only in the case of the more _general_ physiological truths, such as
those above instanced, where we have something like adequate data, that
deductive reasoning becomes possible.

And here is reached the stage to which the foregoing considerations are
introductory. We propose now to show that there are certain still more
general attributes of organized bodies, which are deducible from certain
still more general attributes of things.

       *       *       *       *       *

In an essay on "Progress: its Law and Cause," elsewhere published,[8] we
have endeavoured to show that the transformation of the homogeneous into
the heterogeneous, in which all progress, organic or other, essentially
consists, is consequent on the production of many effects by one
cause--many changes by one force. Having pointed out that this is a law
of all things, we proceeded to show deductively that the multiform
evolutions of the homogeneous into the heterogeneous--astronomic,
geologic, ethnologic, social, &c.,--were explicable as consequences. And
though in the case of organic evolution, lack of data disabled us from
specifically tracing out the progressive complication as due to the
multiplication of effects; yet, we found sundry indirect evidences that
it was so. Now in so far as this conclusion, that organic evolution
results from the decomposition of each expended force into several
forces, was inferred from the general law previously pointed out, it was
an example of deductive physiology. The particular was concluded from
the universal.

We here propose in the first place to show, that there is another
general truth closely connected with the above; and in common with it
underlying explanations of all progress, and therefore the progress of
organisms--a truth which may indeed be considered as taking precedence
of it in respect of time, if not in respect of generality. This truth
is, that _the condition of homogeneity is a condition of unstable
equilibrium_.

The phrase _unstable equilibrium_ is one used in mechanics to express
a balance of forces of such kind, that the interference of any further
force, however minute, will destroy the arrangement previously existing,
and bring about a different arrangement. Thus, a stick poised on its
lower end is in unstable equilibrium: however exactly it may be placed
in a perpendicular position, as soon as it is left to itself it begins,
at first imperceptibly and then visibly, to lean on one side, and with
increasing rapidity falls into another position. Conversely, a stick
suspended from its upper end is in stable equilibrium: however much
disturbed, it will return to the same position. Our meaning is, then,
that the state of homogeneity, like the state of the stick poised on its
lower end, is one that cannot be maintained; and that hence results the
first step in its gravitation towards the heterogeneous. Let us take a
few illustrations.

Of mechanical ones the most familiar is that of the scales. If
accurately made and not clogged by dirt or rust, a pair of scales cannot
be perfectly balanced: eventually one scale will descend and the other
ascend--they will assume a heterogeneous relation. Again, if we sprinkle
over the surface of a liquid a number of equal-sized particles, having
an attraction for one another, they will, no matter how uniformly
distributed, by and by concentrate irregularly into groups. Were it
possible to bring a mass of water into a state of perfect homogeneity--a
state of complete quiescence, and exactly equal density throughout--yet
the radiation of heat from neighbouring bodies, by affecting differently
its different parts, would soon produce inequalities of density and
consequent currents; and would so render it to that extent
heterogeneous. Take a piece of red-hot matter, and however evenly heated
it may at first be, it will quickly cease to be so: the exterior,
cooling faster than the interior, will become different in temperature
from it. And the lapse into heterogeneity of temperature, so obvious in
this extreme case, is ever taking place more or less in all cases. The
actions of chemical forces supply other illustrations. Expose a
fragment of metal to air or water, and in course of time it will be
coated with a film of oxide, carbonate, or other compound: its outer
parts will become unlike its inner parts. Thus, every homogeneous
aggregate of matter tends to lose its balance in some way or
other--either mechanically, chemically, thermally or electrically; and
the rapidity with which it lapses into a non-homogeneous state is simply
a question of time and circumstances. Social bodies illustrate the law
with like constancy. Endow the members of a community with equal
properties, positions, powers, and they will forthwith begin to slide
into inequalities. Be it in a representative assembly, a railway board,
or a private partnership, the homogeneity, though it may continue in
name, inevitably disappears in reality.

The instability thus variously illustrated becomes still more manifest
if we consider its rationale. It is consequent on the fact that the
several parts of any homogeneous mass are necessarily exposed to
different forces--forces which differ either in their kinds or amounts;
and being exposed to different forces they are of necessity differently
modified. The relations of outside and inside, and of comparative
nearness to neighbouring sources of influence, imply the reception of
influences which are unlike in quantity or quality or both; and it
follows that unlike changes will be wrought in the parts dissimilarly
acted upon. The unstable equilibrium of any homogeneous aggregate can
thus be shown both inductively and deductively.

And now let us consider the bearing of this general truth on the
evolution of organisms. The germ of a plant or animal is one of these
homogeneous aggregates--relatively homogeneous if not absolutely
so--whose equilibrium is unstable. But it has not simply the ordinary
instability of homogeneous aggregates: it has something more. For it
consists of units which are themselves specially characterized by
instability. The constituent molecules of organic matter are
distinguished by the feebleness of the affinities which hold their
component elements together. They are extremely sensitive to heat,
light, electricity, and the chemical actions of foreign elements; that
is, they are peculiarly liable to be modified by disturbing forces.
Hence then it follows, _a priori_, that a homogeneous aggregate of these
unstable molecules will have an excessive tendency to lose its
equilibrium. It will have a quite special liability to lapse into a
non-homogeneous state. It will rapidly gravitate towards heretogeneity.

Moreover, the process must repeat itself in each of the subordinate
groups of organic units which are differentiated by the modifying
forces. Each of these subordinate groups, like the original group, must
gradually, in obedience to the influences acting on it, lose its balance
of parts--must pass from a uniform into a multiform state. And so on
continuously.

Thus, starting from the general laws of things, and the known chemical
attributes of organic matter, we may conclude deductively that the
homogeneous germs of organisms have a peculiar proclivity towards a
non-homogeneous state; which may be either the state we call
decomposition, or the state we call organization.

       *       *       *       *       *

At present we have reached a conclusion only of the most general nature.
We merely learn that _some_ kind of heterogeneity is inevitable; but as
yet there is nothing to tell us _what_ kind. Besides that _orderly_
heterogeneity which distinguishes organisms, there is the _disorderly_
or _chaotic_ heterogeneity, into which a loose mass of inorganic matter
lapses; and at present no reason has been given why the homogeneous germ
of a plant or animal should not lapse into the disorderly instead of the
orderly heterogeneity. But by pursuing still further the line of
argument hitherto followed we shall find a reason.

We have seen that the instability of homogeneous aggregates in general,
and of organic ones in particular, is consequent on the various ways and
degrees in which their constituent parts are exposed to the disturbing
forces brought to bear on them: their parts are differently acted upon,
and therefore become different. Manifestly, then, a rationale of the
special changes which a germ undergoes, must be sought in the particular
relations which its several parts bear to each other and to their
environment. However it may be masked, we may suspect the fundamental
principle of organization to be, that the many like units forming a germ
acquire those kinds and degrees of unlikeness which their respective
positions entail.

Take a mass of unorganized but organizable matter--either the body of
one of the lowest living forms, or the germ of one of the higher.
Consider its circumstances. It is immersed in water or air; or it is
contained within a parent organism. Wherever placed, however, its outer
and inner parts stand differently related to surrounding
existences--nutriment, oxygen, and the various stimuli. But this is not
all. Whether it lies quiescent at the bottom of the water, whether it
moves through the water preserving some definite attitude, or whether it
is in the inside of an adult; it equally results that certain parts of
its surface are more directly exposed to surrounding agencies than other
parts--in some cases more exposed to light, heat, or oxygen, and in
others to the maternal tissues and their contents. The destruction of
its original equilibrium is therefore certain. It may take place in one
of two ways. Either the disturbing forces may be such as to overbalance
the affinities of the organic elements, in which case there results that
chaotic heterogeneity known as decomposition; or, as is ordinarily the
case, such changes are induced as do not destroy the organic compounds,
but only modify them: the parts most exposed to the modifying forces
being most modified. Hence result those first differentiations which
constitute incipient organization. From the point of view thus reached,
suppose we look at a few cases: neglecting for the present all
consideration of the tendency to assume the inherited type.

Note first what appear to be exceptions, as the _Amoeba_. In this
creature and its allies, the substance of the jelly-like body remains
throughout life unorganized--undergoes no permanent differentiations.
But this fact, which seems directly opposed to our inference, is really
one of the most significant evidences of its truth. For what is the
peculiarity of the Rhizopods, exemplified by the _Amoeba_? They
undergo perpetual and irregular changes of shape--they show no
persistent relations of parts. What lately formed a portion of the
interior is now protruded, and, as a temporary limb, is attached to some
object it happens to touch. What is now a part of the surface will
presently be drawn, along with the atom of nutriment sticking to it,
into the centre of the mass. Thus there is an unceasing interchange of
places; and the relations of inner and outer have no settled existence.
But by the hypothesis, it is only in virtue of their unlike positions
with respect to modifying forces, that the originally-like units of a
living mass become unlike. We must not therefore expect any established
differentiation of parts in creatures which exhibit no established
differences of position in their parts.

This negative evidence is borne out by abundant positive evidence. When
we turn from these ever-changing specks of living jelly to organisms
having unchanging distributions of substance, we find differences of
tissue corresponding to differences of relative position. In all the
higher _Protozoa_, as also in the _Protophyta_, we meet with a
fundamental differentiation into cell-membrane and cell-contents,
answering to that fundamental contrast of conditions implied by the
words outside and inside. And on passing from what are roughly classed
as unicellular organisms to the lowest of those which consist of
aggregated cells, we equally observe the connexion between structural
differences and differences of circumstance. In the sponge, permeated
throughout by currents of sea-water, the absence of definite
organization corresponds with the absence of definite unlikeness of
conditions. In the _Thalassicolla_ of Professor Huxley--a transparent,
colourless body, found floating passively at the surface of the sea, and
consisting essentially of "a mass of cells united by jelly"--there is
displayed a rude structure obviously subordinated to the primary
relations of centre and surface: in all of its many and important
varieties, the parts exhibit a more or less concentric arrangement.

After this primary modification, by which the outer tissues are
differentiated from the inner, the next in order of constancy and
importance is that by which some part of the outer tissues is
differentiated from the rest; and this corresponds with the almost
universal fact that some part of the outer tissues is more directly
exposed to certain environing influences than the rest. Here, as before,
the apparent exceptions are extremely significant. Some of the lowest
vegetable organisms, as the _Hematococci_ and _Protococci_, evenly
imbedded in a mass of mucus, or dispersed through the Arctic snow,
display no differentiations of surface: the several parts of the surface
being subjected to no definite contrasts of conditions. The
_Thalassicolla_ above mentioned, unfixed, and rolled about by the waves,
presents all its sides successively to the same agencies; and all its
sides are alike. A ciliated sphere like the _Volvox_ has no parts of its
periphery unlike other parts; and it is not to be expected that it
should have; seeing that as it revolves in all directions, it does not,
in traversing the water, permanently expose any part to special
conditions. But when we come to creatures that are either fixed, or
while moving, severally preserve a definite attitude, we no longer find
uniformity of surface. The gemmule of a Zoophyte, which during its
locomotive stage is distinguishable only into outer and inner tissues,
no sooner takes root than its upper end begins to assume a different
structure from its lower. The free-swimming embryo of an aquatic
annelid, being ovate and not ciliated all over, moves with one end
foremost; and its differentiations proceed in conformity with this
contrast of circumstances.

The principle thus displayed in the humbler forms of life, is traceable
during the development of the higher; though being here soon masked by
the assumption of the hereditary type, it cannot be traced far. Thus the
"mulberry-mass" into which a fertilized ovum of a vertebrate animal
first resolves itself, soon begins to exhibit a difference between the
outer and inner parts answering to the difference of circumstances. The
peripheral cells, after reaching a more complete development than the
central ones, coalesce into a membrane enclosing the rest; and then the
cells lying next to these outer ones become aggregated with them, and
increase the thickness of the germinal membrane, while the central cells
liquefy. Again, one part of the germinal membrane presently becomes
distinguishable as the germinal spot; and without asserting that the
cause of this is to be found in the unlike relations which the
respective parts of the germinal membrane bear to environing influences,
it is clear that we have in these unlike relations an element of
disturbance tending to destroy the original homogeneity of the germinal
membrane. Further, the germinal membrane by and by divides into two
layers, internal and external; the one in contact with the liquefied
interior part or yelk, the other exposed to the surrounding fluids: this
contrast of circumstances being in obvious correspondence with the
contrast of structures which follows it. Once more, the subsequent
appearance of the vascular layer between these mucous and serous layers,
as they have been named, admits of a like interpretation. And in this
and the various complications which now begin to show themselves, we may
see coming into play that general law of the multiplication of effects
flowing from one cause, to which the increase of heterogeneity was
elsewhere ascribed.[9]

Confining our remarks, as we do, to the most general facts of
development, we think that some light is thus thrown on them. That the
unstable equilibrium of a homogeneous germ must be destroyed by the
unlike exposure of its several units to surrounding influences, is an _a
priori_ conclusion. And it seems also to be an _a priori_ conclusion,
that the several units thus differently acted upon, must either be
decomposed, or must undergo such modifications of nature as may enable
them to live in the respective circumstances they are thrown into: in
other words--_they must either die or become adapted to their
conditions_. Indeed, we might infer as much without going through the
foregoing train of reasoning. The superficial organic units (be they the
outer cells of a "mulberry-mass," or be they the outer molecules of an
individual cell) must assume the function which their position
necessitates; and assuming this function, must acquire such character as
performance of it involves. The layer of organic units lying in contact
with the yelk must be those through which the yelk is absorbed; and so
must be adapted to the absorbent office. On this condition only does the
process of organization appear possible. We might almost say that just
as some race of animals, which multiplies and spreads into divers
regions of the earth, becomes differentiated into several races through
the adaptation of each to its conditions of life; so, the originally
homogeneous population of cells arising in a fertilized germ-cell,
becomes divided into several populations of cells that grow unlike in
virtue of the unlikeness of their circumstances.

Moreover, it is to be remarked in further proof of our position, that it
finds its clearest and most abundant illustrations where the conditions
of the case are the simplest and most general--where the phenomena are
the least involved: we mean in the production of individual cells. The
structures which presently arise round nuclei in a blastema, and which
have in some way been determined by those nuclei as centres of
influence, evidently conform to the law; for the parts of the blastema
in contact with the nuclei are differently conditioned from the parts
not in contact with them. Again, the formation of a membrane round each
of the masses of granules into which the endochrome of an alga-cell
breaks up, is an instance of analogous kind. And should the
recently-asserted fact that cells may arise round vacuoles in a mass of
organizable substance, be confirmed, another good example will be
furnished; for such portions of substance as bound these vacant spaces
are subject to influences unlike those to which other portions of the
substance are subject. If then we can most clearly trace this law of
modification in these primordial processes, as well as in those more
complex but analogous ones exhibited in the early changes of an ovum, we
have strong reason for thinking that the law is fundamental.

But, as already more than once hinted, this principle, understood in the
simple form here presented, supplies no key to the detailed phenomena of
organic development. It fails entirely to explain generic and specific
peculiarities; and leaves us equally in the dark respecting those more
important distinctions by which families and orders are marked out. Why
two ova, similarly exposed in the same pool, should become the one a
fish, and the other a reptile, it cannot tell us. That from two
different eggs placed under the same hen, should respectively come forth
a duckling and a chicken, is a fact not to be accounted for on the
hypothesis above developed. Here we are obliged to fall back upon the
unexplained principle of hereditary transmission. The capacity possessed
by an unorganized germ of unfolding into a complex adult which repeats
ancestral traits in minute details, and that even when it has been
placed in conditions unlike those of its ancestors, is a capacity
impossible for us to understand. That a microscopic portion of seemingly
structureless matter should embody an influence of such kind, that the
resulting man will in fifty years after become gouty or insane, is a
truth which would be incredible were it not daily illustrated. But
though the _manner_ in which hereditary likeness, in all its
complications, is conveyed, is a mystery passing comprehension, it is
quite conceivable that it is conveyed in subordination to the law of
adaptation above explained; and we are not without reasons for thinking
that it is so. Various facts show that acquired peculiarities resulting
from the adaptation of constitution to conditions, are transmissible to
offspring. Such acquired peculiarities consist of differences of
structure or composition in one or more of the tissues. That is to say,
of the aggregate of similar organic units composing a germ, the group
going to the formation of a particular tissue, will take on the special
character which the adaptation of that tissue to new circumstances had
produced in the parents. We know this to be a general law of organic
modifications. Further, it is the _only_ law of organic modifications of
which we have any evidence.[10] It is not impossible then that it is the
universal law; comprehending not simply those minor modifications which
offspring inherit from recent ancestry, but comprehending also those
larger modifications distinctive of species, genus, order, class, which
they inherit from antecedent races of organisms. And thus it _may be_
that the law of adaptation is the sole law; presiding not only over the
differentiation of any race of organisms into several races, but also
over the differentiation of the race of organic units composing a germ,
into the many races of organic units composing an adult. So understood,
the process gone through by every unfolding organism will consist,
partly in the direct adaptation of its elements to their several
circumstances, and partly in the assumption of characters resulting from
analogous adaptations of the elements of all ancestral organisms.

But our argument does not commit us to any such far-reaching speculation
as this; which we introduce simply as suggested by it, not involved. All
we are here concerned to show, is, that the deductive method aids us in
interpreting some of the more general phenomena of development. That all
homogeneous aggregates are in unstable equilibrium is a universal truth,
from which is deducible the instability of every organic germ. From the
known sensitiveness of organic compounds to chemical, thermal, and other
disturbing forces, we further infer the _unusual_ instability of every
organic germ--a proneness far beyond that of other homogeneous
aggregates to lapse into a heterogeneous state. By the same line of
reasoning we are led to the additional inference, that the first
divisions into which a germ resolves itself, being severally in a state
of unstable equilibrium, are similarly prone to undergo further changes;
and so on continuously. Moreover, we have found it to be equally an _a
priori_ conclusion, that as, in all other cases, the loss of homogeneity
is due to the different degrees and kinds of force brought to bear on
the different parts; so, in this case too, difference of circumstances
is the primary cause of differentiation. Add to which, that as the
several changes undergone by the respective parts thus diversely acted
upon, are changes which do not destroy their vital activity, they must
be changes which bring that vital activity into subordination to the
incident forces--they must be adaptations; and the like must be in some
sense true of all the subsequent changes. Thus by deductive reasoning we
get some insight into the method of organization. However unable we are,
and probably ever shall be, to comprehend the way in which a germ is
made to take on the special form of its race, we may yet comprehend the
general principles which regulate its first modifications; and,
remembering the unity of plan so conspicuous throughout nature, we may
_suspect_ that these principles are in some way concerned in succeeding
modifications.

       *       *       *       *       *

A controversy now going on among zoologists, opens yet another field for
the application of the deductive method. We believe that the question
whether there does or does not exist a _necessary correlation_ among the
several parts of an organism is determinable _a priori_.

Cuvier, who first asserted this necessary correlation, professed to base
his restorations of extinct animals upon it. Geoffroy St. Hilaire and
De Blainville, from different points of view, contested Cuvier's
hypothesis; and the discussion, which has much interest as bearing on
paleontology, has been recently revived under a somewhat modified form:
Professors Huxley and Owen being respectively the assailant and defender
of the hypothesis.

Cuvier says--"Comparative anatomy possesses a principle whose just
development is sufficient to dissipate all difficulties; it is that of
the correlation of forms in organized beings, by means of which every
kind of organized being might, strictly speaking, be recognized by a
fragment of any of its parts. Every organized being constitutes a whole,
a single and complete system, whose parts mutually correspond and concur
by their reciprocal reaction to the same definite end. None of these
parts can be changed without affecting the others; and consequently each
taken separately, indicates and gives all the rest." He then gives
illustrations: arguing that the carnivorous form of tooth necessitating
a certain action of the jaw, implies a particular form in its condyles;
implies also limbs fit for seizing and holding prey; therefore implies
claws, a certain structure of the leg-bones, a certain form of
shoulder-blade. Summing up he says, that "the claw, the scapula, the
condyle, the femur, and all the other bones, taken separately, will give
the tooth or one another; and by commencing with any one, he who had a
rational conception of the laws of the organic economy, could
reconstruct the whole animal."

It will be seen that the method of restoration here contended for, is
based on the alleged physiological necessity of the connexion between
these several peculiarities. The argument used is, not that a scapula of
a certain shape may be recognized as having belonged to a carnivorous
mammal because we always find that carnivorous mammals _do_ possess such
scapulas; but the argument is that they _must_ possess them, because
carnivorous habits would be impossible without them. And in the above
quotation Cuvier asserts that the necessary correlation which he
considers so obvious in these cases, exists throughout the system:
admitting, however, that in consequence of our limited knowledge of
physiology we are unable in many cases to trace this necessary
correlation, and are obliged to base our conclusions upon observed
coexistences, of which we do not understand the reason, but which we
find invariable.

Now Professor Huxley has recently shown that, in the first place, this
empirical method, which Cuvier introduces as quite subordinate, and to
be used only in aid of the rational method, is really the method which
Cuvier habitually employed--the so-called rational method remaining
practically a dead letter; and, in the second place, he has shown that
Cuvier himself has in several places so far admitted the inapplicability
of the rational method, as virtually to surrender it as a method. But
more than this, Professor Huxley contends that the alleged necessary
correlation is not true. Quite admitting the physiological dependence of
parts on each other, he denies that it is a dependence of a kind which
could not be otherwise. "Thus the teeth of a lion and the stomach of
the animal are in such relation that the one is fitted to digest the
food which the other can tear, they are physiologically correlated; but
we have no reason for affirming this to be a necessary physiological
correlation, in the sense that no other could equally fit its possessor
for living on recent flesh. The number and form of the teeth might have
been quite different from that which we know them to be, and the
construction of the stomach might have been greatly altered; and yet the
functions of these organs might have been equally well performed."

Thus much is needful to give an idea of the controversy. It is not here
our purpose to go more at length into the evidence cited on either side.
We simply wish to show that the question may be settled deductively.
Before going on to do this, however, let us briefly notice two
collateral points.

In his defence of the Cuvierian doctrine, Professor Owen avails himself
of the _odium theologicum_. He attributes to his opponents "the
insinuation and masked advocacy of the doctrine subversive of a
recognition of the Higher Mind." Now, saying nothing about the
questionable propriety of thus prejudging an issue in science, we think
this is an unfortunate accusation. What is there in the hypothesis of
_necessary_, as distinguished from _actual_, correlation of parts, which
is particularly in harmony with Theism? Maintenance of the _necessity_,
whether of sequences or of coexistences, is commonly thought rather a
derogation from divine power than otherwise. Cuvier says--"None of these
parts can be changed without affecting the others; and consequently,
each taken separately, indicates and gives all the rest." That is to
say, in the nature of things the correlation _could not_ have been
otherwise. On the other hand, Professor Huxley says we have no warrant
for asserting that the correlation _could not_ have been otherwise; but
have not a little reason for thinking that the same physiological ends
might have been differently achieved. The one doctrine limits the
possibilities of creation; the other denies the implied limit. Which,
then, is most open to the charge of covert Atheism?

On the other point we lean to the opinion of Professor Owen. We agree
with him in thinking that where a rational correlation (in the highest
sense of the term) can be made out, it affords a better basis for
deduction than an empirical correlation ascertained only by accumulated
observations. Premising that by rational correlation is not meant one in
which we can trace, or think we can trace, a design, but one of which
the negation is inconceivable (and this is the species of correlation
which Cuvier's principle implies); then we hold that our knowledge of
the correlation is of a more certain kind than where it is simply
inductive. We think that Professor Huxley, in his anxiety to avoid the
error of making Thought the measure of Things, does not sufficiently
bear in mind the fact, that as our notion of necessity is determined by
some absolute uniformity pervading all orders of our experiences, it
follows that an organic correlation which cannot be conceived otherwise,
is guaranteed by a much wider induction than one ascertained only by the
observation of organisms. But the truth is, that there are relatively
few organic correlations of which the negation is inconceivable. If we
find the skull, vertebræ, ribs, and phalanges of some quadruped as large
as an elephant; we may indeed be certain that the legs of this quadruped
were of considerable size--much larger than those of a rat; and our
reason for conceiving this correlation as necessary, is, that it is
based, not only upon our experiences of moving organisms, but upon all
our mechanical experiences relative to masses and their supports. But
even were there many physiological correlations really of this order,
which there are not, there would be danger in pursuing this line of
reasoning, in consequence of the liability to include within the class
of truly necessary correlations, those which are not such. For instance,
there would seem to be a necessary correlation between the eye and the
surface of the body: light being needful for vision, it might be
supposed that every eye must be external. Nevertheless it is a fact that
there are creatures, as the _Cirrhipedia_, having eyes (not very
efficient ones, it may be) deeply imbedded within the body. Again, a
necessary correlation might be assumed between the dimensions of the
mammalian uterus and those of the pelvis. It would appear impossible
that in any species there should exist a well-developed uterus
containing a full-sized foetus, and yet that the arch of the pelvis
should be too small to allow the foetus to pass. And were the only
mammal having a very small pelvic arch, a fossil one, it would have been
inferred, on the Cuvierian method, that the foetus must have been born
in a rudimentary state; and that the uterus must have been
proportionally small. But there happens to be an extant mammal having an
undeveloped pelvis--the mole--which presents us with a fact that saves
us from this erroneous inference. The young of the mole are not born
through the pelvic arch at all; but in front of it! Thus, granting that
some quite _direct_ physiological correlations may be necessary, we see
that there is great risk of including among them some which are not.

With regard to the great mass of the correlations, however, including
all the _indirect_ ones, Professor Huxley seems to us warranted in
denying that they are necessary; and we now propose to show deductively
the truth of his thesis. Let us begin with an analogy.

Whoever has been through an extensive iron-works, has seen a gigantic
pair of shears worked by machinery, and used for cutting in two, bars of
iron that are from time to time thrust between its blades. Supposing
these blades to be the only visible parts of the apparatus, anyone
observing their movements (or rather the movement of one, for the other
is commonly fixed), will see from the manner in which the angle
increases and decreases, and from the curve described by the moving
extremity, that there must be some centre of motion--either a pivot or
an external box equivalent to it. This may be regarded as a necessary
correlation. Moreover, he might infer that beyond the centre of motion
the moving blade was produced into a lever, to which the power was
applied; but as another arrangement is just possible, this could not be
called anything more than a highly probable correlation. If now he went
a step further, and asked how the reciprocal movement was given to the
lever, he would perhaps conclude that it was given by a crank. But if he
knew anything of mechanics, he would know that it might possibly be
given by an eccentric. Or again, he would know that the effect could be
achieved by a cam. That is to say, he would see that there was no
necessary correlation between the shears and the remoter parts of the
apparatus. Take another case. The plate of a printing-press is required
to move up and down to the extent of an inch or so; and it must exert
its greatest pressure when it reaches the extreme of its downward
movement. If now anyone will look over the stock of a printing-press
maker, he will see half a dozen different mechanical arrangements by
which these ends are achieved; and a machinist would tell him that as
many more might readily be invented. If, then, there is no necessary
correlation between the special parts of a machine, still less is there
between those of an organism.

From a converse point of view the same truth is manifest. Bearing in
mind the above analogy, it will be foreseen that an alteration in one
part of an organism will not necessarily entail _some one specific set
of alterations in the other parts_. Cuvier says, "None of these parts
can be changed without affecting the others; and consequently, each
taken separately, indicates and gives all the rest." The first of these
propositions may pass, but the second, which it is alleged follows from
it, is not true; for it implies that "all the rest" can be severally
affected in only one way and degree, whereas they can be affected in
many ways and degrees. To show this, we must again have recourse to a
mechanical analogy.

If you set a brick on end and thrust it over, you can predict with
certainty in what direction it will fall, and what attitude it will
assume. If, again setting it up, you put another on the top of it, you
can no longer foresee with accuracy the results of an overthrow; and on
repeating the experiment, no matter how much care is taken to place the
bricks in the same positions, and to apply the same degree of force in
the same direction, the effects will on no two occasions be exactly
alike. And in proportion as the aggregation is complicated by the
addition of new and unlike parts, will the results of any disturbance
become more varied and incalculable. The like truth is curiously
illustrated by locomotive engines. It is a fact familiar to mechanical
engineers and engine-drivers, that out of a number of engines built as
accurately as possible to the same pattern, no two will act in just the
same manner. Each will have its peculiarities. The play of actions and
reactions will so far differ, that under like conditions each will
behave in a somewhat different way; and every driver has to learn the
idiosyncrasies of his own engine before he can work it to the greatest
advantage. In organisms themselves this indefiniteness of mechanical
reaction is clearly traceable. Two boys throwing stones will always
differ more or less in their attitudes, as will two billiard-players.
The familiar fact that each individual has a characteristic gait,
illustrates the point still better. The rhythmical motion of the leg is
simple, and on the Cuvierian hypothesis, should react on the body in
some uniform way. But in consequence of those slight differences of
structure which consist with identity of species, no two individuals
make exactly similar movements either of the trunk or the arms. There
is always a peculiarity recognizable by their friends.

When we pass to disturbing forces of a non-mechanical kind, the same
truth becomes still more conspicuous. Expose several persons to a
drenching storm; and while one will subsequently feel no appreciable
inconvenience, another will have a cough, another a catarrh, another an
attack of diarrhoea, another a fit of rheumatism. Vaccinate several
children of the same age with the same quantity of virus, applied to the
same part, and the symptoms will not be quite alike in any of them,
either in kind or intensity; and in some cases the differences will be
extreme. The quantity of alcohol which will send one man to sleep, will
render another unusually brilliant--will make this maudlin, and that
irritable. Opium will produce either drowsiness or wakefulness: so will
tobacco.

Now in all these cases--mechanical and other--some force is brought to
bear primarily on one part of an organism, and secondarily on the rest;
and, according to the doctrine of Cuvier, the rest ought to be affected
in a specific way. We find this to be by no means the case. The original
change produced in one part does not stand in any necessary correlation
with every one of the changes produced in the other parts; nor do these
stand in any necessary correlation with one another. The functional
alteration which the disturbing force causes in the organ directly acted
upon, does not involve some _particular set_ of functional alterations
in the other organs; but will be followed by some one out of various
sets. And it is a manifest corollary, that any _structural alteration_
which may eventually be produced in the one organ, will not be
accompanied by _some particular set of structural alterations_ in the
other organs. There will be no necessary correlation of forms.

Thus Paleontology must depend upon the empirical method. A fossil
species that was obliged to change its food or habits of life, did not
of necessity undergo the particular set of modifications exhibited; but,
under some slight change of predisposing causes--as of season or
latitude--might have undergone some other set of modifications: the
determining circumstance being one which, in the human sense, we call
fortuitous.

May we not say then, that the deductive method elucidates this vexed
question in physiology; while at the same time our argument collaterally
exhibits the limits within which the deductive method is applicable. For
while we see that this extremely _general_ question may be
satisfactorily dealt with deductively; the conclusion arrived at itself
implies that the more _special_ phenomena of organization cannot be so
dealt with.

       *       *       *       *       *

There is yet another method of investigating the general truths of
physiology--a method to which physiology already owes one luminous idea,
but which is not at present formally recognized as a method. We refer to
the comparison of physiological phenomena with social phenomena.

The analogy between individual organisms and the social organism, is one
that has from early days occasionally forced itself on the attention of
the observant. And though modern science does not countenance those
crude ideas of this analogy which have been from time to time expressed
since the Greeks flourished; yet it tends to show that there _is_ an
analogy, and a remarkable one. While it is becoming clear that there are
not those special parallelisms between the constituent parts of a man
and those of a nation, which have been thought to exist; it is also
becoming clear that the general principles of development and structure
displayed in organized bodies are displayed in societies also. The
fundamental characteristic both of societies and of living creatures,
is, that they consist of mutually-dependent parts; and it would seem
that this involves a community of various other characteristics. Those
who are acquainted with the broad facts of both physiology and
sociology, are beginning to recognize this correspondence not as a
plausible fancy, but as a scientific truth. And we are strongly of
opinion that it will by and by be seen to hold to an extent which few at
present suspect.

Meanwhile, if any such correspondence exists, it is clear that
physiology and sociology will more or less interpret each other. Each
affords its special facilities for inquiry. Relations of cause and
effect clearly traceable in the social organism, may lead to the search
for analogous ones in the individual organism; and may so elucidate what
might else be inexplicable. Laws of growth and function disclosed by the
pure physiologist, may occasionally give us the clue to certain social
modifications otherwise difficult to understand. If they can do no more,
the two sciences can at least exchange suggestions and confirmations;
and this will be no small aid. The conception of "the physiological
division of labour," which political economy has already supplied to
physiology, is one of no small value. And probably it has others to
give.

In support of this opinion, we will now cite cases in which such aid is
furnished. And in the first place, let us see whether the facts of
social organization do not afford additional support to some of the
doctrines set forth in the foregoing parts of this article.

One of the propositions supported by evidence was that in animals the
process of development is carried on, not by differentiations only, but
by subordinate integrations. Now in the social organism we may see the
same duality of process; and further, it is to be observed that the
integrations are of the same three kinds. Thus we have integrations
which arise from the simple growth of adjacent parts that perform like
functions: as, for instance, the coalescence of Manchester with its
calico-weaving suburbs. We have other integrations which arise when, out
of several places producing a particular commodity, one monopolizes
more and more of the business, and leaves the rest to dwindle: witness
the growth of the Yorkshire cloth-districts at the expense of those in
the west of England; or the absorption by Staffordshire of the
pottery-manufacture, and the consequent decay of the establishments that
once flourished at Worcester, Derby, and elsewhere. And we have those
yet other integrations which result from the actual approximation of the
similarly-occupied parts: whence result such facts as the concentration
of publishers in Paternoster Row, of lawyers in the Temple and
neighbourhood, of corn-merchants about Mark Lane, of civil engineers in
Great George Street, of bankers in the centre of the city. Finding thus
that in the evolution of the social organism, as in the evolution of
individual organisms, there are integrations as well as
differentiations, and moreover that these integrations are of the same
three orders; we have additional reason for considering these
integrations as essential parts of the developmental process, needed to
be included in its formula. And further, the circumstance that in the
social organism these integrations are determined by community of
function, confirms the hypothesis that they are thus determined in the
individual organism.

Again, we endeavoured to show deductively, that the contrasts of parts
first seen in all unfolding embryos, are consequent upon the contrasted
circumstances to which such parts are exposed; that thus, adaptation of
constitution to conditions is the principle which determines their
primary changes; and that, possibly, if we include under the formula
hereditarily-transmitted adaptations, all subsequent differentiations
may be similarly determined. Well, we need not long contemplate the
facts to see that some of the predominant social differentiations are
brought about in an analogous way. As the members of an
originally-homogeneous community multiply and spread, the gradual
separation into sections which simultaneously takes place, manifestly
depends on differences of local circumstances. Those who happen to
live near some place chosen, perhaps for its centrality, as one of
periodical assemblage, become traders, and a town springs up; those who
live dispersed, continue to hunt or cultivate the earth; those who
spread to the sea-shore fall into maritime occupations. And each of
these classes undergoes modifications of character fitting to its
function. Later in the process of social evolution these local
adaptations are greatly multiplied. In virtue of differences of soil and
climate, the rural inhabitants in different parts of the kingdom, have
their occupations partially specialized; and are respectively
distinguished as chiefly producing cattle, or sheep, or wheat, or oats,
or hops, or cider. People living where coal-fields are discovered become
colliers; Cornishmen take to mining because Cornwall is metalliferous;
and the iron-manufacture is the dominant industry where ironstone is
plentiful. Liverpool has assumed the office of importing cotton, in
consequence of its proximity to the district where cotton goods are
made; and for analogous reasons Hull has become the chief port at which
foreign wools are brought in. Even in the establishment of breweries, of
dye-works, of slate-quarries, of brick-yards, we may see the same truth.
So that, both in general and in detail, these industrial specializations
of the social organism which characterize separate districts, primarily
depend on local circumstances. Of the originally-similar units making up
the social mass, different groups assume the different functions which
their respective positions entail; and become adapted to their
conditions. Thus, that which we concluded, _a priori_, to be the leading
cause of organic differentiations, we find, _a posteriori_, to be the
leading cause of social differentiations. Nay further, as we inferred
that possibly the embryonic changes which are not thus directly caused,
are caused by hereditarily-transmitted adaptations; so, we may actually
see that in embryonic societies, such changes as are not due to direct
adaptations, are in the main traceable to adaptations originally
undergone by the parent society. The colonies founded by distinct
nations, while they are alike in exhibiting specializations caused in
the way above described, grow unlike in so far as they take on, more or
less, the organizations of the nations they sprung from. A French
settlement does not develop exactly after the same manner as an English
one; and both assume forms different from those which Roman settlements
assumed. Now the fact that the differentiation of societies is
determined partly by the direct adaptation of their units to local
conditions, and partly by the transmitted influence of like adaptations
undergone by ancestral societies, tends strongly to enforce the
conclusion, otherwise reached, that the differentiation of individual
organisms, similarly results from immediate adaptations compounded with
ancestral adaptations.

From confirmations thus furnished by sociology to physiology, let us now
pass to a suggestion similarly furnished. A factory, or other producing
establishment, or a town made up of such establishments, is an agency
for elaborating some commodity consumed by society at large; and may be
regarded as analogous to a gland or viscus in an individual organism. If
we inquire what is the primitive mode in which one of these producing
establishments grows up, we find it to be this. A single worker, who
himself sells the produce of his labour, is the germ. His business
increasing, he employs helpers--his sons or others; and having done
this, he becomes a vendor not only of his own handiwork, but of that of
others. A further increase of his business compels him to multiply his
assistants, and his sale grows so rapid that he is obliged to confine
himself to the process of selling: he ceases to be a producer, and
becomes simply a channel through which the produce of others is conveyed
to the public. Should his prosperity rise yet higher, he finds that he
is unable to manage even the sale of his commodities, and has to employ
others, probably of his own family, to aid him in selling; so that, to
him as a main channel are now added subordinate channels. Moreover, when
there grow up in one place, as a Manchester or a Birmingham, many
establishments of like kind, this process is carried still further.
There arise factors and buyers, who are the channels through which is
transmitted the produce of many factories; and we believe that primarily
these factors were manufacturers who undertook to dispose of the produce
of smaller houses as well as their own, and ultimately became salesmen
only. Under a converse aspect, all the stages of this development have
been within these few years exemplified in our railway contractors.
There are sundry men now living who illustrate the whole process in
their own persons--men who were originally navvies, digging and
wheeling; who then undertook some small sub-contract, and worked along
with those they paid; who presently took larger contracts, and employed
foremen; and who now contract for whole railways, and let portions to
sub-contractors. That is to say, we have men who were originally
workers, but have finally become the main channels out of which diverge
secondary channels, which again bifurcate into the subordinate channels,
through which flows the money (representing the nutriment) supplied by
society to the actual makers of the railway. Now it seems worth
inquiring whether this is not the original course followed in the
evolution of secreting and excreting organs in an animal. We know that
such is the process by which the liver is developed. Out of the group of
bile-cells forming the germ of it, some centrally-placed ones, lying
next to the intestine, are transformed into ducts through which the
secretion of the peripheral bile-cells is poured into the intestine; and
as the peripheral bile-cells multiply, there similarly arise secondary
ducts emptying themselves into the main ones; tertiary ones into these;
and so on. Recent inquiries show that the like is the case with the
lungs,--that the bronchial tubes are thus formed. But while analogy
suggests that this is the _original_ mode in which such organs are
developed, it at the same time suggests that this does not necessarily
continue to be the mode. For as we find that in the social organism,
manufacturing establishments are no longer commonly developed through
the series of modifications above described, but now mostly arise by the
direct transformation of a number of persons into master, clerks,
foremen, workers, &c.; so the approximate method of forming organs, may
in some cases be replaced by a direct metamorphosis of the organic units
into the destined structure, without any transitional structures being
passed through. That there are organs thus formed is an ascertained
fact; and the additional question which analogy suggests is, whether the
direct method is substituted for the indirect method.

Such parallelisms might be multiplied. And were it possible here to show
in detail the close correspondence between the two kinds of
organization, our case would be seen to have abundant support. But, as
it is, these few illustrations will sufficiently justify the opinion
that study of organized bodies may be indirectly furthered by study of
the body politic. Hints may be expected, if nothing more. And thus we
venture to think that the Inductive Method, usually alone employed by
most physiologists, may not only derive important assistance from the
Deductive Method, but may further be supplemented by the Sociological
Method.

FOOTNOTES:

[Footnote 6: Carpenter's _Principles of Comparative Physiology_, pp.
616-17.]

[Footnote 7: With the exception, perhaps, of the Myxinoid fishes, in
which what is considered as the nasal orifice is single, and on the
median line. But seeing how unusual is the position of this orifice, it
seems questionable whether it is the true homologue of the nostrils.]

[Footnote 8: In the _Westminster Review_ for April, 1857; and now
reprinted in this volume.]

[Footnote 9: See Essay on "Progress: its Law and Cause."]

[Footnote 10: This was written before the publication of the _Origin of
Species_. I leave it standing because it shows the stage of thought then
arrived at.]




THE NEBULAR HYPOTHESIS.

    [_First published in_ The Westminster Review _for July,_ 1858. _In
    explanation of sundry passages, it seems needful to state that this
    essay was written in defence of the Nebular Hypothesis at a time
    when it had fallen into disrepute. Hence there are some opinions
    spoken of as current which are no longer current._]


Inquiring into the pedigree of an idea is not a bad means of roughly
estimating its value. To have come of respectable ancestry, is _prima
facie_ evidence of worth in a belief as in a person; while to be
descended from a discreditable stock is, in the one case as in the
other, an unfavourable index. The analogy is not a mere fancy. Beliefs,
together with those who hold them, are modified little by little in
successive generations; and as the modifications which successive
generations of the holders undergo do not destroy the original type, but
only disguise and refine it, so the accompanying alterations of belief,
however much they purify, leave behind the essence of the original
belief.

Considered genealogically, the received theory respecting the creation
of the Solar System is unmistakably of low origin. You may clearly trace
it back to primitive mythologies. Its remotest ancestor is the doctrine
that the celestial bodies are personages who originally lived on the
Earth--a doctrine still held by some of the negroes Livingstone visited.
Science having divested the sun and planets of their divine
personalities, this old idea was succeeded by the idea which even Kepler
entertained, that the planets are guided in their courses by presiding
spirits: no longer themselves gods, they are still severally kept in
their orbits by gods. And when gravitation came to dispense with these
celestial steersmen, there was begotten a belief, less gross than its
parent, but partaking of the same essential nature, that the planets
were originally launched into their orbits by the Creator's hand.
Evidently, though much refined, the anthropomorphism of the current
hypothesis is inherited from the aboriginal anthropomorphism, which
described gods as a stronger order of men.

There is an antagonist hypothesis which does not propose to honour the
Unknown Power manifested in the Universe, by such titles as "The
Master-Builder," or "The Great Artificer;" but which regards this
Unknown Power as probably working after a method quite different from
that of human mechanics. And the genealogy of this hypothesis is as high
as that of the other is low. It is begotten by that ever-enlarging and
ever-strengthening belief in the presence of Law, which accumulated
experiences have gradually produced in the human mind. From generation
to generation Science has been proving uniformities of relation among
phenomena which were before thought either fortuitous or supernatural in
their origin--has been showing an established order and a constant
causation where ignorance had assumed irregularity and arbitrariness.
Each further discovery of Law has increased the presumption that Law is
everywhere conformed to. And hence, among other beliefs, has arisen the
belief that the Solar System originated, not by _manufacture_ but by
_evolution_. Besides its abstract parentage in those grand general
conceptions which Science has generated, this hypothesis has a concrete
parentage of the highest character. Based as it is on the law of
universal gravitation, it may claim for its remote progenitor the great
thinker who established that law. It was first suggested by one who
ranks high among philosophers. The man who collected evidence indicating
that stars result from the aggregation of diffused matter, was the most
diligent, careful, and original astronomical observer of modern times.
And the world has not seen a more learned mathematician than the man
who, setting out with this conception of diffused matter concentrating
towards its centre of gravity, pointed out the way in which there would
arise, in the course of its concentration, a balanced group of sun,
planets, and satellites, like that of which the Earth is a member.

Thus, even were there but little direct evidence assignable for the
Nebular Hypothesis, the probability of its truth would be strong. Its
own high derivation and the low derivation of the antagonist hypothesis,
would together form a weighty reason for accepting it--at any rate,
provisionally. But the direct evidence assignable for the Nebular
Hypothesis is by no means little. It is far greater in quantity, and
more varied in kind, than is commonly supposed. Much has been said here
and there on this or that class of evidences; but nowhere, so far as we
know, have all the evidences been fully stated. We propose here to do
something towards supplying the deficiency: believing that, joined with
the _a priori_ reasons given above, the array of _a posteriori_ reasons
will leave little doubt in the mind of any candid inquirer.

And first, let us address ourselves to those recent discoveries in
stellar astronomy which have been supposed to conflict with this
celebrated speculation.

       *       *       *       *       *

When Sir William Herschel, directing his great reflector to various
nebulous spots, found them resolvable into clusters of stars, he
inferred, and for a time maintained, that all nebulous spots are
clusters of stars exceedingly remote from us. But after years of
conscientious investigation, he concluded that "there were nebulosities
which are not of a starry nature;" and on this conclusion was based his
hypothesis of a diffused luminous fluid which, by its eventual
aggregation, produced stars. A telescopic power much exceeding that used
by Herschel, has enabled Lord Rosse to resolve some of the nebulæ
previously unresolved; and, returning to the conclusion which Herschel
first formed on similar grounds but afterwards rejected, many
astronomers have assumed that, under sufficiently high powers, every
nebula would be decomposed into stars--that the irresolvability is due
solely to distance. The hypothesis now commonly entertained is, that all
nebulæ are galaxies more or less like in nature to that immediately
surrounding us; but that they are so inconceivably remote as to look,
through ordinary telescopes, like small faint spots. And not a few have
drawn the corollary, that by the discoveries of Lord Rosse the Nebular
Hypothesis has been disproved.

Now, even supposing that these inferences respecting the distances and
natures of the nebulæ are valid, they leave the Nebular Hypothesis
substantially as it was. Admitting that each of these faint spots is a
sidereal system, so far removed that its countless stars give less light
than one small star of our own sidereal system; the admission is in no
way inconsistent with the belief that stars, and their attendant
planets, have been formed by the aggregation of nebulous matter. Though,
doubtless, if the existence of nebulous matter now in course of
concentration be disproved, one of the evidences of the Nebular
Hypothesis is destroyed, yet the remaining evidences remain. It is a
tenable position that though nebular condensation is now nowhere to be
seen in progress, yet it was once going on universally. And, indeed, it
might be argued that the still-continued existence of diffused nebulous
matter is scarcely to be expected; seeing that the causes which have
resulted in the aggregation of one mass, must have been acting on all
masses, and that hence the existence of masses not aggregated would be a
fact calling for explanation. Thus, granting the immediate conclusions
suggested by these recent disclosures of the six-feet reflector, the
corollary which many have drawn is inadmissible.

But these conclusions may be successfully contested. Receiving them
though we have been, for years past, as established truths, a critical
examination of the facts has convinced us that they are quite
unwarrantable. They involve so many manifest incongruities, that we have
been astonished to find men of science entertaining them, even as
probable. Let us consider these incongruities.

       *       *       *       *       *

In the first place, mark what is inferable from the distribution of
nebulæ.

     "The spaces which precede or which follow simple nebulæ," says
     Arago, "and _a fortiori_, groups of nebulæ, contain generally few
     stars. Herschel found this rule to be invariable. Thus every time
     that during a short interval no star approached in virtue of the
     diurnal motion, to place itself in the field of his motionless
     telescope, he was accustomed to say to the secretary who assisted
     him,--'Prepare to write; nebulæ are about to arrive.'"

How does this fact consist with the hypothesis that nebulæ are remote
galaxies? If there were but one nebula, it would be a curious
coincidence were this one nebula so placed in the distant regions of
space, as to agree in direction with a starless spot in our own sidereal
system. If there were but two nebulæ, and both were so placed, the
coincidence would be excessively strange. What, then, shall we say on
finding that there are thousands of nebulæ so placed? Shall we believe
that in thousands of cases these far-removed galaxies happen to agree in
their visible positions with the thin places in our own galaxy? Such a
belief is impossible.

Still more manifest does the impossibility of it become when we consider
the general distribution of nebulæ. Besides again showing itself in the
fact that "the poorest regions in stars are near the richest in nebulæ,"
the law above specified applies to the heavens as a whole. In that zone
of celestial space where stars are excessively abundant, nebulæ are
rare; while in the two opposite celestial spaces that are furthest
removed from this zone, nebulæ are abundant. Scarcely any nebulæ lie
near the galactic circle (or plane of the Milky Way); and the great
mass of them lie round the galactic poles. Can this also be mere
coincidence? When to the fact that the general mass of nebulæ are
antithetical in position to the general mass of stars, we add the fact
that local regions of nebulæ are regions where stars are scarce, and the
further fact that single nebulæ are habitually found in comparatively
starless spots; does not the proof of a physical connexion become
overwhelming? Should it not require an infinity of evidence to show that
nebulæ are not parts of our sidereal system? Let us see whether any such
infinity of evidence is assignable. Let us see whether there is even a
single alleged proof which will bear examination.

     "As seen through colossal telescopes," says Humboldt, "the
     contemplation of these nebulous masses leads us into regions from
     whence a ray of light, according to an assumption not wholly
     improbable, requires millions of years to reach our earth--to
     distances for whose measurement the dimensions (the distance of
     Sirius, or the calculated distances of the binary stars in Cygnus
     and the Centaur) of our nearest stratum of fixed stars scarcely
     suffice."

In this confused sentence there is implied a belief, that the distances
of the nebulæ from our galaxy of stars as much transcend the distances
of our stars from one another, as these interstellar distances transcend
the dimensions of our planetary system. Just as the diameter of the
Earth's orbit, is a mere point when compared with the distance of our
Sun from Sirius; so is the distance of our Sun from Sirius, a mere point
when compared with the distance of our galaxy from those far-removed
galaxies constituting nebulæ. Observe the consequences of this
assumption.

If one of these supposed galaxies is so remote that its distance dwarfs
our interstellar spaces into points, and therefore makes the dimensions
of our whole sidereal system relatively insignificant; does it not
inevitably follow that the telescopic power required to resolve this
remote galaxy into stars, must be incomparably greater than the
telescopic power required to resolve the whole of our own galaxy into
stars? Is it not certain that an instrument which can just exhibit with
clearness the most distant stars of our own cluster, must be utterly
unable to separate one of these remote clusters into stars? What, then,
are we to think when we find that the same instrument which decomposes
hosts of nebulæ into stars, _fails_ to resolve completely our own Milky
Way? Take a homely comparison. Suppose a man who was surrounded by a
swarm of bees, extending, as they sometimes do, so high in the air as to
render some of the individual bees almost invisible, were to declare
that a certain spot on the horizon was a swarm of bees; and that he knew
it because he could see the bees as separate specks. Incredible as the
assertion would be, it would not exceed in incredibility this which we
are criticising. Reduce the dimensions to figures, and the absurdity
becomes still more palpable. In round numbers, the distance of Sirius
from the Earth is half a million times the distance of the Earth from
the Sun; and, according to the hypothesis, the distance of a nebula is
something like half a million times the distance of Sirius. Now, our own
"starry island, or nebula," as Humboldt calls it, "forms a lens-shaped,
flattened, and everywhere detached stratum, whose major axis is
estimated at seven or eight hundred, and its minor axis at a hundred and
fifty times the distance of Sirius from the Earth."[11] And since it is
concluded that the Solar System is near the centre of this aggregation,
it follows that our distance from the remotest parts of it is some four
hundred distances of Sirius. But the stars forming these remotest parts
are not individually visible, even through telescopes of the highest
power. How, then, can such telescopes make individually visible the
stars of a nebula which is half a million times the distance of Sirius?
The implication is, that a star rendered invisible by distance becomes
visible if taken twelve hundred times further off! Shall we accept this
implication? or shall we not rather conclude that the nebulæ are _not_
remote galaxies? Shall we not infer that, be their nature what it may,
they must be at least as near to us as the extremities of our own
sidereal system?

Throughout the above argument, it is tacitly assumed that differences of
apparent magnitude among the stars, result mainly from differences of
distance. On this assumption the current doctrines respecting the nebulæ
are founded; and this assumption is, for the nonce, admitted in each of
the foregoing criticisms. From the time, however, when it was first made
by Sir W. Herschel, this assumption has been purely gratuitous; and it
now proves to be inadmissible. But, awkwardly enough, its truth and its
untruth are alike fatal to the conclusions of those who argue after the
manner of Humboldt. Note the alternatives.

On the one hand, what follows from the untruth of the assumption? If
apparent largeness of stars is not due to comparative nearness, and
their successively smaller sizes to their greater and greater degrees of
remoteness, what becomes of the inferences respecting the dimensions of
our sidereal system and the distances of nebulæ? If, as has lately been
shown, the almost invisible star 61 Cygni has a greater parallax than
[Greek: a] Cygni, though, according to an estimate based on Sir W.
Herschel's assumption, it should be about twelve times more distant--if,
as it turns out, there exist telescopic stars which are nearer to us
than Sirius; of what worth is the conclusion that the nebulæ are very
remote, because their component luminous masses are made visible only by
high telescopic powers? Clearly, if the most brilliant star in the
heavens and a star that cannot be seen by the naked eye, prove to be
equidistant, relative distances cannot be in the least inferred from
relative visibilities. And if so, nebulæ may be comparatively near,
though the starlets of which they are made up appear extremely minute.

On the other hand, what follows if the truth of the assumption be
granted? The arguments used to justify this assumption in the case of
the stars, equally justify it in the case of the nebulæ. It cannot be
contended that, on the average, the _apparent_ sizes of the stars
indicate their distances, without its being admitted that, on the
average, the _apparent_ sizes of the nebulæ indicate their
distances--that, generally speaking, the larger are the nearer and the
smaller are the more distant. Mark, now, the necessary inference
respecting their resolvability. The largest or nearest nebulæ will be
most easily resolved into stars; the successively smaller will be
successively more difficult of resolution; and the irresolvable ones
will be the smallest ones. This, however, is exactly the reverse of the
fact. The largest nebulæ are either wholly irresolvable, or but
partially resolvable under the highest telescopic powers; while large
numbers of quite small nebulæ are easily resolved by far less powerful
telescopes. An instrument through which the great nebula in Andromeda,
two and a half degrees long and one degree broad, appears merely as a
diffused light, decomposes a nebula of fifteen minutes diameter into
twenty thousand starry points. At the same time that the individual
stars of a nebula eight minutes in diameter are so clearly seen as to
allow of their number being estimated, a nebula covering an area five
hundred times as great shows no stars at all! What possible explanation
of this can be given on the current hypothesis?

Yet a further difficulty remains--one which is, perhaps, still more
obviously fatal than the foregoing. This difficulty is presented by the
phenomena of the Magellanic clouds. Describing the larger of these, Sir
John Herschel says:--

     "The Nubecula Major, like the Minor, consists partly of large
     tracts and ill-defined patches of irresolvable nebula, and of
     nebulosity in every stage of resolution, up to perfectly resolved
     stars like the Milky Way, as also of regular and irregular nebulæ
     properly so called, of globular clusters in every stage of
     resolvability, and of clustering groups sufficiently insulated and
     condensed to come under the designation of 'clusters of
     stars.'"--_Cape Observations_, p. 146.

In his _Outlines of Astronomy_, Sir John Herschel, after repeating this
description in other words, goes on to remark that--

     "This combination of characters, rightly considered, is in a high
     degree instructive, affording an insight into the probable
     comparative distance of _stars_ and _nebulæ_, and the real
     brightness of individual stars as compared with one another. Taking
     the apparent semidiameter of the nubecula major at three degrees,
     and regarding its solid form as, roughly speaking, spherical, its
     nearest and most remote parts differ in their distance from us by a
     little more than a tenth part of our distance from its center. The
     brightness of objects situated in its nearer portions, therefore,
     cannot be _much_ exaggerated, nor that of its remoter _much_
     enfeebled, by their difference of distance; yet within this
     globular space, we have collected upwards of six hundred stars of
     the seventh, eighth, ninth, and tenth magnitudes, nearly three
     hundred nebulæ, and globular and other clusters, _of all degrees of
     resolvability_, and smaller scattered stars innumerable of every
     inferior magnitude, from the tenth to such as by their multitude
     and minuteness constitute irresolvable nebulosity, extending over
     tracts of many square degrees. Were there but one such object, it
     might be maintained without utter improbability that its apparent
     sphericity is only an effect of foreshortening, and that in reality
     a much greater proportional difference of distance between its
     nearer and more remote parts exists. But such an adjustment,
     improbable enough in one case, must be rejected as too much so for
     fair argument in two. It must, therefore, be taken as a
     demonstrated fact, that stars of the seventh or eighth magnitude
     and irresolvable nebula may co-exist within limits of distance not
     differing in proportion more than as nine to ten."--_Outlines of
     Astronomy_ (10th Ed.), pp. 656-57.

This supplies yet another _reductio ad absurdum_ of the doctrine we are
combating. It gives us the choice of two incredibilities. If we are to
believe that one of these included nebulæ is so remote that its hundred
thousand stars look like a milky spot, invisible to the naked eye; we
must also believe that there are single stars so enormous that though
removed to this same distance they remain visible. If we accept the
other alternative, and say that many nebulæ are no further off than our
own stars of the eighth magnitude; then it is requisite to say that at
a distance not greater than that at which a single star is still
faintly visible to the naked eye, there may exist a group of a hundred
thousand stars which is invisible to the naked eye. Neither of these
suppositions can be entertained. What, then, is the conclusion that
remains? This only:--that the nebulæ are not further from us than parts
of our own sidereal system, of which they must be considered members;
and that when they are resolvable into discrete masses, these masses
cannot be considered as stars in anything like the ordinary sense of
that word.[12]

And now, having seen the untenability of this idea, rashly espoused by
sundry astronomers, that the nebulæ are extremely remote galaxies; let
us consider whether the various appearances they present are not
reconcilable with the Nebular Hypothesis.

       *       *       *       *       *

Given a rare and widely-diffused mass of nebulous matter, having a
diameter, say, of one hundred times that of the Solar System,[13] what
are the successive changes that may be expected to take place in it?
Mutual gravitation will approximate its atoms or its molecules; but
their approximation will be opposed by that atomic motion the resultant
of which we recognize as repulsion, and the overcoming of which implies
the evolution of heat. As fast as this heat partially escapes by
radiation, further approximation will take place, attended by further
evolution of heat, and so on continuously: the processes not occurring
separately as here described, but simultaneously, uninterruptedly, and
with increasing activity. When the nebulous mass has reached a
particular stage of condensation--when its internally-situated atoms
have approached to within certain distances, have generated a certain
amount of heat, and are subject to a certain mutual pressure,
combinations may be anticipated. Whether the molecules produced be of
kinds such as we know, which is possible, or whether they be of kinds
simpler than any we know, which is more probable, matters not to the
argument. It suffices that molecular unions, either between atoms of the
same kind or between atoms of different kinds, will finally take place.
When they do take place, they will be accompanied by a sudden and great
disengagement of heat; and until this excess of heat has escaped, the
newly-formed molecules will remain uniformly diffused, or, as it were,
dissolved in the pre-existing nebulous medium.

But now what may be expected by and by to happen? When radiation has
adequately lowered the temperature, these molecules will precipitate;
and, having precipitated, they will not remain uniformly diffused, but
will aggregate into flocculi; just as water, precipitated from air,
collects into clouds. Concluding, thus, that a nebulous mass will, in
course of time, resolve itself into flocculi of precipitated denser
matter, floating in the rarer medium from which they were precipitated,
let us inquire what are the mechanical results to be inferred. Of
clustered bodies in empty space, each will move along a line which is
the resultant of the tractive forces exercised by all the rest, modified
from moment to moment by the acquired motion; and the aggregation of
such clustered bodies, if it eventually results at all, can result only
from collision, dissipation, and the formation of a resisting medium.
But with clustered bodies already immersed in a resisting medium, and
especially if such bodies are of small densities, such as those we are
considering, the process of concentration will begin forthwith: two
factors conspiring to produce it. The flocculi described, irregular in
their shapes and presenting, as they must in nearly all cases,
unsymmetrical faces to their lines of motion, will be deflected from
those courses which mutual gravitation, if uninterfered with, would
produce among them; and this will militate against that balancing of
movements which permanence of the cluster pre-supposes. If it be said,
as it may truly be said, that this is too trifling a cause of
derangement to produce much effect, then there comes the more important
cause with which it co-operates. The medium from which the flocculi have
been precipitated, and through which they are moving, must, by
gravitation, be rendered denser in its central parts than in its
peripheral parts. Hence the flocculi, none of them moving in straight
lines to the common centre of gravity, but having courses made to
diverge to one or other side of it (in small degrees by the cause just
assigned, and in much greater degrees by the tractive forces of other
flocculi) will, in moving towards the central region, meet with greater
resistances on their inner sides than on their outer sides; and will be
thus made to diverge outwardly from their courses more than they would
otherwise do. Hence a tendency which, apart from other tendencies, will
cause them severally to go on one or other side of the centre of
gravity, and, approaching it, to get motions more and more tangential.
Observe, however, that their respective motions will be deflected, not
towards one side of the common centre of gravity, but towards various
sides. How then can there result a movement common to them all? Very
simply. Each flocculus, in describing its course, must give motion to
the medium through which it is moving. But the probabilities are
infinity to one against all the respective motions thus impressed on
this medium, exactly balancing one another. And if they do not balance
one another the result must be rotation of the whole mass of the medium
in one direction. But preponderating momentum in one direction, having
caused rotation of the medium in that direction, the rotating medium
must in its turn gradually arrest such flocculi as are moving in
opposition, and impress its own motion upon them; and thus there will
ultimately be formed a rotating medium with suspended flocculi partaking
of its motion, while they move in converging spirals towards the common
centre of gravity.[14]

Before comparing these conclusions with facts, let us pursue the
reasoning a little further, and observe certain subordinate actions. The
respective flocculi must be drawn not towards their common centre of
gravity only, but also towards neighbouring flocculi. Hence the whole
assemblage of flocculi will break up into groups: each group
concentrating towards its local centre of gravity, and in so doing
acquiring a vortical movement like that subsequently acquired by the
whole nebula. According to circumstances, and chiefly according to the
size of the original nebulous mass, this process of local aggregation
will produce various results. If the whole nebula is but small, the
local groups of flocculi may be drawn into the common centre of gravity
before their constituent masses have coalesced with one another. In a
larger nebula, these local aggregations may have concentrated into
rotating spheroids of vapour, while yet they have made but little
approach towards the general focus of the system. In a still larger
nebula, where the local aggregations are both greater and more remote
from the common centre of gravity, they may have condensed into masses
of molten matter before the general distribution of them has greatly
altered. In short, as the conditions in each case determine, the
discrete masses produced may vary indefinitely in number, in size, in
density, in motion, in distribution.

And now let us return to the visible characters of nebulæ, as observed
through modern telescopes. Take first the description of those nebulæ
which, by the hypothesis, must be in an early stage of evolution.

     Among the "_irregular nebulæ_," says Sir John Herschel, "may be
     comprehended all which, to _a want of complete and in most
     instances even of partial resolvability_ by the power of the
     20-feet reflector, unite such a deviation from the circular or
     elliptic form, or such a want of symmetry (with that form) as
     preclude their being placed in class 1, or that of Regular Nebulæ.
     This second class comprises many of the most remarkable and
     interesting objects in the heavens, _as well as the most extensive
     in respect of the area they occupy_."

And, referring to this same order of objects, M. Arago says:--"The forms
of very large diffuse nebulæ do not appear to admit of definition; they
have no regular outline."

This coexistence of largeness, irregularity, and indefiniteness of
outline, with irresolvability, is extremely significant. The fact that
the largest nebulæ are either irresolvable or very difficult to resolve,
might have been inferred _a priori_; seeing that irresolvability,
implying that the aggregation of precipitated matter has gone on to but
a small extent, will be found in nebulæ of wide diffusion. Again, the
irregularity of these large, irresolvable nebulæ, might also have been
expected; seeing that their outlines, compared by Arago with "the
fantastic figures which characterize clouds carried away and tossed
about by violent and often contrary winds," are similarly characteristic
of a mass not yet gathered together by the mutual attraction of its
parts. And once more, the fact that these large, irregular, irresolvable
nebulæ have indefinite outlines--outlines that fade off insensibly into
surrounding darkness--is one of like meaning.

Speaking generally (and of course differences of distance negative
anything beyond average statements), the spiral nebulæ are smaller than
the irregular nebulæ, and more resolvable; at the same time that they
are not so small as the regular nebulæ, and not so resolvable. This is
as, according to the hypothesis, it should be. The degree of
condensation causing spiral movement, is a degree of condensation also
implying masses of flocculi that are larger, and therefore more visible,
than those existing in an earlier stage. Moreover, the forms of these
spiral nebulæ are quite in harmony with the explanation given. The
curves of luminous matter which they exhibit, are _not_ such as would be
described by discrete masses starting from a state of rest, and moving
through a resisting medium to a common centre of gravity; but they _are_
such as would be described by masses having their movements modified by
the rotation of the medium.

In the centre of a spiral nebula is seen a mass both more luminous and
more resolvable than the rest. Assume that, in process of time, all the
spiral streaks of luminous matter which converge to this centre are
drawn into it, as they must be; assume further, that the flocculi, or
other discrete portions constituting these luminous streaks, aggregate
into larger masses at the same time that they approach the central
group, and that the masses forming this central group also aggregate
into larger masses; and there will finally result a cluster of such
larger masses, which will be resolvable with comparative ease. And, as
the coalescence and concentration go on, the constituent masses will
gradually become fewer, larger, brighter, and more densely collected
around the common centre of gravity. See now how completely this
inference agrees with observation. "The circular form is that which most
commonly characterises resolvable nebulæ," writes Arago. Resolvable
nebulæ, says Sir John Herschel, "are almost universally round or oval."
Moreover, the centre of each group habitually displays a closer
clustering of the constituent masses than the outer parts; and it is
shown that, under the law of gravitation, which we now know extends to
the stars, this distribution is _not_ one of equilibrium, but implies
progressing concentration. While, just as we inferred that, according to
circumstances, the extent to which aggregation has been carried must
vary; so we find that, in fact, there are regular nebulæ of all degrees
of resolvability, from those consisting of innumerable minute masses, to
those in which their numbers are smaller and the sizes greater, and to
those in which there are a few large bodies worthy to be called stars.

On the one hand, then, we see that the notion, of late years
uncritically received, that the nebulæ are extremely remote galaxies of
stars like those which make up our own Milky Way, is totally
irreconcilable with the facts--involves us in sundry absurdities. On the
other hand, we see that the hypothesis of nebular condensation
harmonizes with the most recent results of stellar astronomy: nay
more--that it supplies us with an explanation of various appearances
which in its absence would be incomprehensible.

       *       *       *       *       *

Descending now to the Solar System, let us consider first a class of
phenomena in some sort transitional--those offered by comets. In them,
or at least in those most numerous of them which lie far out of the
plane of the Solar System, and are not to be counted among its members,
we have, still existing, a kind of matter like that out of which,
according to the Nebular Hypothesis, the Solar System was evolved.
Hence, for the explanation of them, we must go back to the time when the
substances forming the sun and planets were yet unconcentrated.

When diffused matter, precipitated from a rarer medium, is aggregating,
there are certain to be here and there produced small flocculi, which
long remain detached; as do, for instance, minute shreds of cloud in a
summer sky. In a concentrating nebula these will, in the majority of
cases, eventually coalesce with the larger flocculi near to them. But it
is tolerably evident that some of those formed at the outermost parts of
the nebula, will _not_ coalesce with the larger internal masses, but
will slowly follow without overtaking them. The relatively greater
resistance of the medium necessitates this. As a single feather falling
to the ground will be rapidly left behind by a pillow-full of feathers;
so, in their progress to the common centre of gravity, will the
outermost shreds of vapour be left behind by the great masses of vapour
internally situated. But we are not dependent merely on reasoning for
this belief. Observation shows us that the less concentrated external
parts of nebulæ, _are_ left behind by the more concentrated internal
parts. Examined through high powers, all nebulæ, even when they have
assumed regular forms, are seen to be surrounded by luminous streaks, of
which the directions show that they are being drawn into the general
mass. Still higher powers bring into view still smaller, fainter, and
more widely-dispersed streaks. And it cannot be doubted that the minute
fragments which no telescopic aid makes visible, are yet more numerous
and widely dispersed. Thus far, then, inference and observation are at
one.

Granting that the great majority of these outlying portions of nebulous
matter will be drawn into the central mass long before it reaches a
definite form, the presumption is that some of the very small,
far-removed portions will not be so; but that before they arrive near
it, the central mass will have contracted into a comparatively moderate
bulk. What now will be the characters of these late-arriving portions?

In the first place, they will have either extremely eccentric orbits or
non-elliptic paths. Left behind at a time when they were moving towards
the centre of gravity in slightly-deflected lines, and therefore having
but very small angular velocities, they will approach the central mass
in greatly elongated curves; and rushing round it, will go off again
into space. That is, they will behave just as we see the majority of
comets do; the orbits of which are either so eccentric as to be
indistinguishable from parabolas, or else are not orbits at all, but are
paths which are distinctly either parabolic or hyperbolic.

In the second place, they will come from all parts of the heavens. Our
supposition implies that they were left behind at a time when the
nebulous mass was of irregular shape, and had not acquired a definite
rotation; and as the separation of them would not be from any one
surface of the nebulous mass more than another, the conclusion must be
that they will come to the central body from various directions in
space. This, too, is exactly what happens. Unlike planets, whose orbits
approximate to one plane, comets have orbits that show no relation to
one another; but cut the plane of the ecliptic at all angles, and have
axes inclined to it at all angles.

In the third place, these remotest flocculi of nebulous matter will, at
the outset, be deflected from their direct courses to the common centre
of gravity, not all on one side, but each on such side as its form, or
its original proper motion, determines. And being left behind before the
rotation of the nebula is set up, they will severally retain their
different individual motions. Hence, following the concentrated mass,
they will eventually go round it on all sides; and as often from right
to left as from left to right. Here again the inference perfectly
corresponds with the facts. While all the planets go round the sun from
west to east, comets as often go round the sun from east to west as from
west to east. Of 262 comets recorded since 1680, 130 are direct, and 132
are retrograde. This equality is what the law of probabilities would
indicate.

Then, in the fourth place, the physical constitution of comets accords
with the hypothesis.[15] The ability of nebulous matter to concentrate
into a concrete form, depends on its mass. To bring its ultimate atoms
into that proximity requisite for chemical union--requisite, that is,
for the production of denser matter--their repulsion must be overcome.
The only force antagonistic to their repulsion, is their mutual
gravitation. That their mutual gravitation may generate a pressure and
temperature of sufficient intensity, there must be an enormous
accumulation of them; and even then the approximation can slowly go on
only as fast as the evolved heat escapes. But where the quantity of
atoms is small, and therefore the force of mutual gravitation small,
there will be nothing to coerce the atoms into union. Whence we infer
that these detached fragments of nebulous matter will continue in
their original state. Non-periodic comets seem to do so.

We have already seen that this view of the origin of comets harmonizes
with the characters of their orbits; but the evidence hence derived is
much stronger than was indicated. The great majority of cometary orbits
are classed as parabolic; and it is ordinarily inferred that they are
visitors from remote space, and will never return. But are they rightly
classed as parabolic? Observations on a comet moving in an extremely
eccentric ellipse, which are possible only when it is comparatively near
perihelion, must fail to distinguish its orbit from a parabola.
Evidently, then, it is not safe to class it as a parabola because of
inability to detect the elements of an ellipse. But if extreme
eccentricity of an orbit necessitates such inability, it seems quite
possible that comets have no other orbits than elliptic ones. Though
five or six are said to be hyperbolic, yet, as I learn from one who has
paid special attention to comets, "no such orbit has, I believe, been
computed for a well-observed comet." Hence the probability that all the
orbits are ellipses is overwhelming. Ellipses and hyperbolas have
countless varieties of forms, but there is only one form of parabola;
or, to speak literally, all parabolas are similar, while there are
infinitely numerous dissimilar ellipses and dissimilar hyperbolas.
Consequently, anything coming to the Sun from a great distance must have
one exact amount of proper motion to produce a parabola: all other
amounts would give hyperbolas or ellipses. And if there are no
hyperbolic orbits, then it is infinity to one that all the orbits are
elliptical. This is just what they would be if comets had the genesis
above supposed.

       *       *       *       *       *

And now, leaving these erratic bodies, let us turn to the more familiar
and important members of the Solar System. It was the remarkable harmony
among their movements which first made Laplace conceive that the Sun,
planets, and satellites had resulted from a common genetic process. As
Sir William Herschel, by his observations on the nebulæ, was led to the
conclusion that stars resulted from the aggregation of diffused matter;
so Laplace, by his observations on the structure of the Solar System,
was led to the conclusion that only by the rotation of aggregating
matter were its peculiarities to be explained. In his _Exposition du
Système du Monde_, he enumerates as the leading evidences:--1. The
movements of the planets in the same direction and in orbits approaching
to the same plane; 2. The movements of the satellites in the same
direction as those of the planets; 3. The movements of rotation of these
various bodies and of the sun in the same direction as the orbital
motions, and mostly in planes little different; 4. The small
eccentricities of the orbits of the planets and satellites, as
contrasted with the great eccentricities of the cometary orbits. And the
probability that these harmonious movements had a common cause, he
calculates as two hundred thousand billions to one.

This immense preponderance of probability does not point to a common
cause under the form ordinarily conceived--an Invisible Power working
after the method of "a Great Artificer;" but to an Invisible Power
working after the method of evolution. For though the supporters of the
common hypothesis may argue that it was necessary for the sake of
stability that the planets should go round the Sun in the same direction
and nearly in one plane, they cannot thus account for the direction of
the axial motions.[16] The mechanical equilibrium would not have been
interfered with, had the Sun been without any rotatory movement; or had
he revolved on his axis in a direction opposite to that in which the
planets go round him; or in a direction at right angles to the average
plane of their orbits. With equal safety the motion of the Moon round
the Earth might have been the reverse of the Earth's motion round its
axis; or the motions of Jupiter's satellites might similarly have been
at variance with his axial motion; or those of Saturn's satellites with
his. As, however, none of these alternatives have been followed, the
uniformity must be considered, in this case as in all others, evidence
of subordination to some general law--implies what we call natural
causation, as distinguished from arbitrary arrangement.

Hence the hypothesis of evolution would be the only probable one, even
in the absence of any clue to the particular mode of evolution. But when
we have, propounded by a mathematician of the highest authority, a
theory of this evolution based on established mechanical principles,
which accounts for these various peculiarities, as well as for many
minor ones, the conclusion that the Solar System _was_ evolved becomes
almost irresistible.

The general nature of Laplace's theory scarcely needs stating. Books of
popular astronomy have familiarized most readers with his
conceptions;--namely, that the matter now condensed into the Solar
System, once formed a vast rotating spheroid of extreme rarity extending
beyond the orbit of the outermost planet; that as this spheroid
contracted, its rate of rotation necessarily increased; that by
augmenting centrifugal force its equatorial zone was from time to time
prevented from following any further the concentrating mass, and so
remained behind as a revolving ring; that each of the revolving rings
thus periodically detached, eventually became ruptured at its weakest
point, and, contracting on itself, gradually aggregated into a rotating
mass; that this, like the parent mass, increased in rapidity of rotation
as it decreased in size, and, where the centrifugal force was
sufficient, similarly left behind rings, which finally collapsed into
rotating spheroids; and that thus, out of these primary and secondary
rings, there arose planets and their satellites, while from the central
mass there resulted the Sun. Moreover, it is tolerably well known that
this _a priori_ reasoning harmonizes with the results of experiment. Dr.
Plateau has shown that when a mass of fluid is, as far may be, protected
from the action of external forces, it will, if made to rotate with
adequate velocity, form detached rings; and that these rings will break
up into spheroids which turn on their axes in the same direction with
the central mass. Thus, given the original nebula, which, acquiring a
vortical motion in the way indicated, has at length concentrated into a
vast spheroid of aeriform matter moving round its axis--given this, and
mechanical principles explain the rest. The genesis of a Solar System
displaying movements like those observed, may be predicted; and the
reasoning on which the prediction is based is countenanced by
experiment.[17]

But now let us inquire whether, besides these most conspicuous
structural and dynamic peculiarities of the Solar System, sundry minor
ones are not similarly explicable.

       *       *       *       *       *

Take first the relation between the planes of the planetary orbits and
the plane of the Sun's equator. If, when the nebulous spheroid extended
beyond the orbit of Neptune, all parts of it had been revolving exactly
in the same plane, or rather in parallel planes--if all its parts had
had one axis; then the planes of the successive rings would have been
coincident with each other and with that of the Sun's rotation. But it
needs only to go back to the earlier stages of concentration, to see
that there could exist no such complete uniformity of motion. The
flocculi, already described as precipitated from an irregular and
widely-diffused nebula, and as starting from all points to their common
centre of gravity, must move not in one plane but in innumerable planes,
cutting each other at all angles. The gradual establishment of a
vortical motion such as we at present see indicated in the spiral
nebulæ, is the gradual approach towards motion in one plane. But this
plane can but slowly become decided. Flocculi not moving in this plane,
but entering into the aggregation at various inclinations, will tend to
perform their revolutions round its centre in their own planes; and only
in course of time will their motions be partly destroyed by conflicting
ones, and partly resolved into the general motion. Especially will the
outermost portions of the rotating mass retain for a long time their
more or less independent directions. Hence the probabilities are, that
the planes of the rings first detached will differ considerably from the
average plane of the mass; while the planes of those detached latest
will differ from it less.

Here, again, inference to a considerable extent agrees with observation.
Though the progression is irregular, yet, on the average, the
inclinations decrease on approaching the Sun; and this is all we can
expect. For as the portions of the nebulous spheroid must have arrived
with miscellaneous inclinations, its strata must have had planes of
rotation diverging from the average plane in degrees not always
proportionate to their distances from the centre.

       *       *       *       *       *

Consider next the movements of the planets on their axes. Laplace
alleged as one among other evidences of a common genetic cause, that the
planets rotate in a direction the same as that in which they go round
the Sun, and on axes approximately perpendicular to their orbits. Since
he wrote, an exception to this general rule has been discovered in the
case of Uranus, and another still more recently in the case of
Neptune--judging, at least, from the motions of their respective
satellites. This anomaly has been thought to throw considerable doubt on
his speculation; and at first sight it does so. But a little reflection
shows that the anomaly is not inexplicable, and that Laplace simply went
too far in putting down as a certain result of nebular genesis, what is,
in some instances, only a probable result. The cause he pointed out as
determining the direction of rotation, is the greater absolute velocity
of the outer part of the detached ring. But there are conditions under
which this difference of velocity may be too insignificant, even if it
exists. If a mass of nebulous matter approaching spirally to the central
spheroid, and eventually joining it tangentially, is made up of parts
having the same absolute velocities; then, after joining the equatorial
periphery of the spheroid and being made to rotate with it, the angular
velocity of its outer parts will be smaller than the angular velocity of
its inner parts. Hence, if, when the angular velocities of the outer and
inner parts of a detached ring are the same, there results a tendency to
rotation in the same direction with the orbital motion, it may be
inferred that when the outer parts of the ring have a smaller angular
velocity than the inner parts, a tendency to retrograde rotation will be
the consequence.

Again, the sectional form of the ring is a circumstance of moment; and
this form must have differed more or less in every case. To make this
clear, some illustration will be necessary. Suppose we take an orange,
and, assuming the marks of the stalk and the calyx to represent the
poles, cut off round the line of the equator a strip of peel. This strip
of peel, if placed on the table with its ends meeting, will make a ring
shaped like the hoop of a barrel--a ring of which the thickness in the
line of its diameter is very small, but of which the width in a
direction perpendicular to its diameter is considerable. Suppose, now,
that in place of an orange, which is a spheroid of very slight
oblateness, we take a spheroid of very great oblateness, shaped somewhat
like a lens of small convexity. If from the edge or equator of this
lens-shaped spheroid, a ring of moderate size were cut off, it would be
unlike the previous ring in this respect, that its greatest thickness
would be in the line of its diameter, and not in a line at right angles
to its diameter: it would be a ring shaped somewhat like a quoit, only
far more slender. That is to say, according to the oblateness of a
rotating spheroid, the detached ring may be either a hoop-shaped ring or
a quoit-shaped ring.

One further implication must be noted. In a much-flattened or
lens-shaped spheroid, the form of the ring will vary with its bulk. A
very slender ring, taking off just the equatorial surface, will be
hoop-shaped; while a tolerably massive ring, trenching appreciably on
the diameter of the spheroid, will be quoit-shaped. Thus, then,
according to the oblateness of the spheroid and the bulkiness of the
detached ring, will the greatest thickness of that ring be in the
direction of its plane, or in a direction perpendicular to its plane.
But this circumstance must greatly affect the rotation of the resulting
planet. In a decidedly hoop-shaped nebulous ring, the differences of
velocity between the inner and outer surfaces will be small; and such a
ring, aggregating into a mass of which the greatest diameter is at right
angles to the plane of the orbit, will almost certainly give to this
mass a predominant tendency to rotate in a direction at right angles to
the plane of the orbit. Where the ring is but little hoop-shaped, and
the difference between the inner and outer velocities greater, as it
must be, the opposing tendencies--one to produce rotation in the plane
of the orbit, and the other, rotation perpendicular to it--will both be
influential; and an intermediate plane of rotation will be taken up.
While, if the nebulous ring is decidedly quoit-shaped, and therefore
aggregates into a mass whose greatest dimension lies in the plane of
the orbit, both tendencies will conspire to produce rotation in that
plane.

On referring to the facts, we find them, as far as can be judged, in
harmony with this view. Considering the enormous circumference of
Uranus's orbit, and his comparatively small mass, we may conclude that
the ring from which he resulted was a comparatively slender, and
therefore a hoop-shaped one: especially as the nebulous mass must have
been at that time less oblate than afterwards. Hence, a plane of
rotation nearly perpendicular to his orbit, and a direction of rotation
having no reference to his orbital movement. Saturn has a mass seven
times as great, and an orbit of less than half the diameter; whence it
follows that his genetic ring, having less than half the circumference,
and less than half the vertical thickness (the spheroid being then
certainly _as_ oblate, and indeed _more_ oblate), must have had a much
greater width--must have been less hoop-shaped, and more approaching to
the quoit-shaped: notwithstanding difference of density, it must have
been at least two or three times as broad in the line of its plane.
Consequently, Saturn has a rotatory movement in the same direction as
the movement of translation, and in a plane differing from it by thirty
degrees only. In the case of Jupiter, again, whose mass is three and a
half times that of Saturn, and whose orbit is little more than half the
size, the genetic ring must, for the like reasons, have been still
broader--decidedly quoit-shaped, we may say; and there hence resulted a
planet whose plane of rotation differs from that of his orbit by
scarcely more than three degrees. Once more, considering the comparative
insignificance of Mars, Earth, Venus, and Mercury, it follows that, the
diminishing circumferences of the rings not sufficing to account for the
smallness of the resulting masses, the rings must have been slender
ones--must have again approximated to the hoop-shaped; and thus it
happens that the planes of rotation again diverge more or less widely
from those of the orbits. Taking into account the increasing oblateness
of the original spheroid in the successive stages of its concentration,
and the different proportions of the detached rings, it may fairly be
held that the respective rotatory motions are not at variance with the
hypothesis but contrariwise tend to confirm it.

Not only the directions, but also the velocities of rotation seem thus
explicable. It might naturally be supposed that the large planets would
revolve on their axes more slowly than the small ones: our terrestrial
experiences of big and little bodies incline us to expect this. It is a
corollary from the Nebular Hypothesis, however, more especially when
interpreted as above, that while large planets will rotate rapidly,
small ones will rotate slowly; and we find that in fact they do so.
Other things equal, a concentrating nebulous mass which is diffused
through a wide space, and whose outer parts have, therefore, to travel
from great distances to the common centre of gravity, will acquire a
high axial velocity in course of its aggregation; and conversely with a
small mass. Still more marked will be the difference where the form of
the genetic ring conspires to increase the rate of rotation. Other
things equal, a genetic ring which is broadest in the direction of its
plane will produce a mass rotating faster than one which is broadest at
right angles to its plane; and if the ring is absolutely as well as
relatively broad, the rotation will be very rapid. These conditions
were, as we saw, fulfilled in the case of Jupiter; and Jupiter turns
round his axis in less than ten hours. Saturn, in whose case, as above
explained, the conditions were less favourable to rapid rotation, takes
nearly ten hours and a half. While Mars, Earth, Venus, and Mercury,
whose rings must have been slender, take more than double that time: the
smallest taking the longest.

       *       *       *       *       *

From the planets let us now pass to the satellites. Here, beyond the
conspicuous facts commonly adverted to, that they go round their
primaries in the directions in which these turn on their axes, in planes
diverging but little from their equators, and in orbits nearly circular,
there are several significant traits which must not be passed over.

One of them is that each set of satellites repeats in miniature the
relations of the planets to the Sun, both in certain respects above
named and in the order of their sizes. On progressing from the outside
of the Solar System to its centre, we see that there are four large
external planets, and four internal ones which are comparatively small.
A like contrast holds between the outer and inner satellites in every
case. Among the four satellites of Jupiter, the parallel is maintained
as well as the comparative smallness of the number allows: the two outer
ones are the largest, and the two inner ones the smallest. According to
the most recent observations made by Mr. Lassell, the like is true of
the four satellites of Uranus. In the case of Saturn, who has eight
secondary planets revolving round him, the likeness is still more close
in arrangement as in number: the three outer satellites are large, the
inner ones small; and the contrasts of size are here much greater
between the largest, which is nearly as big as Mars, and the smallest,
which is with difficulty discovered even by the best telescopes. But the
analogy does not end here. Just as with the planets, there is at first a
general increase of size on travelling inwards from Neptune and Uranus,
which do not differ very widely, to Saturn, which is much larger, and to
Jupiter, which is the largest; so of the eight satellites of Saturn, the
largest is not the outermost, but the outermost save two; so of
Jupiter's four secondaries, the largest is the most remote but one. Now
these parallelisms are inexplicable by the theory of final causes. For
purposes of lighting, if this be the presumed object of these attendant
bodies, it would have been far better had the larger been the nearer: at
present, their remoteness renders them of less service than the
smallest. To the Nebular Hypothesis, however, these analogies give
further support. They show the action of a common physical cause. They
imply a _law_ of genesis, holding in the secondary systems as in the
primary system.

Still more instructive shall we find the distribution of the
satellites--their absence in some instances, and their presence in other
instances, in smaller or greater numbers. The argument from design fails
to account for this distribution. Supposing it be granted that planets
nearer the Sun than ourselves, have no need of moons (though,
considering that their nights are as dark, and, relatively to their
brilliant days, even darker than ours, the need seems quite as
great)--supposing this to be granted; how are we to explain the fact
that Uranus has but half as many moons as Saturn, though he is at double
the distance? While, however, the current presumption is untenable, the
Nebular Hypothesis furnishes us with an explanation. It enables us to
predict where satellites will be abundant and where they will be absent.
The reasoning is as follows.

In a rotating nebulous spheroid which is concentrating into a planet,
there are at work two antagonist mechanical tendencies--the centripetal
and the centrifugal. While the force of gravitation draws all the atoms
of the spheroid together, their tangential momentum is resolvable into
two parts, of which one resists gravitation. The ratio which this
centrifugal force bears to gravitation, varies, other things equal, as
the square of the velocity. Hence, the aggregation of a rotating
nebulous spheroid will be more or less hindered by this resisting force,
according as the rate of rotation is high or low: the opposition, in
equal spheroids, being four times as great when the rotation is twice as
rapid; nine times as great when it is three times as rapid; and so on.
Now the detachment of a ring from a planet-forming body of nebulous
matter, implies that at its equatorial zone the increasing centrifugal
force consequent on concentration has become so great as to balance
gravity. Whence it is tolerably obvious that the detachment of rings
will be most frequent from those masses in which the centrifugal
tendency bears the greatest ratio to the gravitative tendency. Though it
is not possible to calculate what ratio these two tendencies had to each
other in the genetic spheroid which produced each planet, it is possible
to calculate where each was the greatest and where the least. While it
is true that the ratio which centrifugal force now bears to gravity at
the equator of each planet, differs widely from that which it bore
during the earlier stages of concentration; and while it is true that
this change in the ratio, depending on the degree of contraction each
planet has undergone, has in no two cases been the same; yet we may
fairly conclude that where the ratio is still the greatest, it has been
the greatest from the beginning. The satellite-forming tendency which
each planet had, will be approximately indicated by the proportion now
existing in it between the aggregating power, and the power that has
opposed aggregation. On making the requisite calculations, a remarkable
harmony with this inference comes out. The following table shows what
fraction the centrifugal force is of the centripetal force in every
case; and the relation which that fraction bears to the number of
satellites.[18]

   Mercury.  1/360
   Venus.    1/253
   Earth.    1/289    1 Satellite.
   Mars.     1/127    2 Satellites.
   Jupiter.  1/11·4   4 Satellites.
   Saturn.   1/6·4    8 Satellites, and three rings.
   Uranus.   1/10·9   4 Satellites.

Thus taking as our standard of comparison the Earth with its one moon,
we see that Mercury, in which the centrifugal force is relatively less,
has no moon. Mars, in which it is relatively much greater, has two
moons. Jupiter, in which it is far greater, has four moons. Uranus, in
which it is greater still, has certainly four, and more if Herschel was
right. Saturn, in which it is the greatest, being nearly one-sixth of
gravity, has, including his rings, eleven attendants. The only instance
in which there is nonconformity with observation, is that of Venus. Here
it appears that the centrifugal force is relatively greater than in the
Earth; and, according to the hypothesis, Venus ought to have a
satellite. Respecting this anomaly several remarks are to be made.
Without putting any faith in the alleged discovery of a satellite of
Venus (repeated at intervals by five different observers), it may yet be
contended that as the satellites of Mars eluded observation up to 1877,
a satellite of Venus may have eluded observation up to the present time.
Merely naming this as possible, but not probable, a consideration of
more weight is that the period of rotation of Venus is but indefinitely
fixed, and that a small diminution in the estimated angular velocity of
her equator would bring the result into congruity with the hypothesis.
Further, it may be remarked that not exact, but only general, congruity
is to be expected; since the process of condensation of each planet from
nebulous matter can scarcely be expected to have gone on with absolute
uniformity: the angular velocities of the superposed strata of nebulous
matter probably differed from one another in degrees unlike in each
case; and such differences would affect the satellite-forming tendency.
But without making much of these possible explanations of the
discrepancy, the correspondence between inference and fact which we find
in so many planets, may be held to afford strong support to the Nebular
Hypothesis.

Certain more special peculiarities of the satellites must be mentioned
as suggestive. One of them is the relation between the period of
revolution and that of rotation. No discoverable purpose is served by
making the Moon go round its axis in the same time that it goes round
the Earth: for our convenience, a more rapid axial motion would have
been equally good; and for any possible inhabitants of the Moon, much
better. Against the alternative supposition, that the equality occurred
by accident, the probabilities are, as Laplace says, infinity to one.
But to this arrangement, which is explicable neither as the result of
design nor of chance, the Nebular Hypothesis furnishes a clue. In his
_Exposition du Système du Monde_, Laplace shows, by reasoning too
detailed to be here repeated, that under the circumstances such a
relation of movements would be likely to establish itself.

Among Jupiter's satellites, which severally display these same
synchronous movements, there also exists a still more remarkable
relation. "If the mean angular velocity of the first satellite be added
to twice that of the third, the sum will be equal to three times that of
the second;" and "from this it results that the situations of any two of
them being given, that of the third can be found." Now here, as before,
no conceivable advantage results. Neither in this case can the connexion
have been accidental: the probabilities are infinity to one to the
contrary. But again, according to Laplace, the Nebular Hypothesis
supplies a solution. Are not these significant facts?

Most significant fact of all, however, is that presented by the rings of
Saturn. As Laplace remarks, they are, as it were, still extant witnesses
of the genetic process he propounded. Here we have, continuing
permanently, forms of aggregation like those through which each planet
and satellite once passed; and their movements are just what, in
conformity with the hypothesis, they should be. "La durée de la rotation
d'une planète doit donc être, d'après cette hypothèse, plus petite que
la durée de la révolution du corps le plus voisin qui circule autour
d'elle," says Laplace. And he then points out that the time of Saturn's
rotation is to that of his rings as 427 to 438--an amount of difference
such as was to be expected.[19]

Respecting Saturn's rings it may be further remarked that the place of
their occurrence is not without significance.

Rings detached early in the process of concentration, consisting of
gaseous matter having extremely little power of cohesion, can have
little ability to resist the disruptive forces due to imperfect balance;
and, therefore, collapse into satellites. A ring of a denser kind,
whether solid, liquid, or composed of small discrete masses (as Saturn's
rings are now concluded to be), we can expect will be formed only near
the body of a planet when it has reached so late a stage of
concentration that its equatorial portions contain matters capable of
easy precipitation into liquid and, finally, solid forms. Even then it
can be produced only under special conditions. Gaining a
rapidly-increasing preponderance as the gravitative force does during
the closing stages of concentration, the centrifugal force cannot, in
ordinary cases, cause the leaving behind of rings when the mass has
become dense. Only where the centrifugal force has all along been very
great, and remains powerful to the last, as in Saturn, can we expect
dense rings to be formed.

We find, then, that besides those most conspicuous peculiarities of the
Solar System which first suggested the theory of its evolution, there
are many minor ones pointing in the same direction. Were there no other
evidence, these mechanical arrangements would, considered in their
totality, go far to establish the Nebular Hypothesis.

       *       *       *       *       *

From the mechanical arrangements of the Solar System, turn we now to its
physical characters; and, first, let us consider the inferences
deducible from relative specific gravities.

The fact that, speaking generally, the denser planets are the nearer to
the Sun, has been by some considered as adding another to the many
indications of nebular origin. Legitimately assuming that the outermost
parts of a rotating nebulous spheroid, in its earlier stages of
concentration, must be comparatively rare; and that the increasing
density which the whole mass acquires as it contracts, must hold of the
outermost parts as well as the rest; it is argued that the rings
successively detached will be more and more dense, and will form planets
of higher and higher specific gravities. But passing over other
objections, this explanation is quite inadequate to account for the
facts. Using the Earth as a standard of comparison, the relative
densities run thus:--

   Neptune. Uranus. Saturn. Jupiter. Mars. Earth. Venus. Mercury. Sun.
    0·17     0·25    0·11    0·23    0·45   1·00   0·92   1·26    0·25

Two insurmountable objections are presented by this series. The first
is, that the progression is but a broken one. Neptune is denser than
Saturn, which, by the hypothesis, it ought not to be. Uranus is denser
than Jupiter, which it ought not to be. Uranus is denser than Saturn,
and the Earth is denser than Venus--facts which not only give no
countenance to, but directly contradict, the alleged explanation. The
second objection, still more manifestly fatal, is the low specific
gravity of the Sun. If, when the matter of the Sun filled the orbit of
Mercury, its state of aggregation was such that the detached ring formed
a planet having a specific gravity equal to that of iron; then the Sun
itself, now that it has concentrated, should have a specific gravity
much greater than that of iron; whereas its specific gravity is only
half as much again as that of water. Instead of being far denser than
the nearest planet, it is but one-fifth as dense.

While these anomalies render untenable the position that the relative
specific gravities of the planets are direct indications of nebular
condensation; it by no means follows that they negative it. Several
causes may be assigned for these unlikenesses:--1. Differences among the
planets in respect of the elementary substances composing them; or in
the proportions of such elementary substances, if they contain the same
kinds. 2. Differences among them in respect of the quantities of matter
they contain; for, other things equal, the mutual gravitation of
molecules will make a larger mass denser than a smaller. 3. Differences
of temperatures; for, other things equal, those having higher
temperatures will have lower specific gravities. 4. Differences of
physical states, as being gaseous, liquid, or solid; or, otherwise,
differences in the relative amounts of the solid, liquid, and gaseous
matter they contain.

It is quite possible, and we may indeed say probable, that all these
causes come into play, and that they take various shares in the
production of the several results. But difficulties stand in the way of
definite conclusions. Nevertheless, if we revert to the hypothesis of
nebular genesis, we are furnished with partial explanations if nothing
more.

In the cooling of celestial bodies several factors are concerned. The
first and simplest is the one illustrated at every fire-side by the
rapid blackening of little cinders which fall into the ashes, in
contrast with the long-continued redness of big lumps. This factor is
the relation between increase of surface and increase of content:
surfaces, in similar bodies, increasing as the squares of the dimensions
while contents increase as their cubes. Hence, on comparing the Earth
with Jupiter, whose diameter is about eleven times that of the Earth, it
results that while his surface is 125 times as great, his content is
1390 times as great. Now even (supposing we assume like temperatures and
like densities) if the only effect were that through a given area of
surface eleven times more matter had to be cooled in the one case than
in the other, there would be a vast difference between the times
occupied in concentration. But, in virtue of a second factor, the
difference would be much greater than that consequent on these
geometrical relations. The escape of heat from a cooling mass is
effected by conduction, or by convection, or by both. In a solid it is
wholly by conduction; in a liquid or gas the chief part is played by
convection--by circulating currents which continually transpose the
hotter and cooler parts. Now in fluid spheroids--gaseous, or liquid, or
mixed--increasing size entails an increasing obstacle to cooling,
consequent on the increasing distances to be travelled by the
circulating currents. Of course the relation is not a simple one: the
velocities of the currents will be unlike. It is manifest, however, that
in a sphere of eleven times the diameter, the transit of matter from
centre to surface and back from surface to centre, will take a much
longer time; even if its movement is unrestrained. But its movement is,
in such cases as we are considering, greatly restrained. In a rotating
spheroid there come into play retarding forces augmenting with the
velocity of rotation. In such a spheroid the respective portions of
matter (supposing them equal in their angular velocities round the axis,
which they will tend more and more to become as the density increases),
must vary in their absolute velocities according to their distances from
the axis; and each portion cannot have its distance from the axis
changed by circulating currents, which it must continually be, without
loss or gain in its quantity of motion: through the medium of fluid
friction, force must be expended, now in increasing its motion and now
in retarding its motion. Hence, when the larger spheroid has also a
higher velocity of rotation, the relative slowness of the circulating
currents, and the consequent retardation of cooling, must be much
greater than is implied by the extra distances to be travelled.

And now observe the correspondence between inference and fact. In the
first place, if we compare the group of the great planets, Jupiter,
Saturn, and Uranus, with the group of the small planets, Mars, Earth,
Venus, and Mercury, we see that low density goes along with great size
and great velocity of rotation, and that high density goes along with
small size and small velocity of rotation. In the second place, we are
shown this relation still more clearly if we compare the extreme
instances--Saturn and Mercury. The special contrast of these two, like
the general contrast of the groups, points to the truth that low
density, like the satellite-forming tendency, is associated with the
ratio borne by centrifugal force to gravity; for in the case of Saturn
with his many satellites and least density, centrifugal force at the
equator is nearly 1/6th of gravity, whereas in Mercury with no satellite
and greatest density centrifugal force is but 1/360th of gravity.

There are, however, certain factors which, working in an opposite way,
qualify and complicate these effects. Other things equal, mutual
gravitation among the parts of a large mass will cause a greater
evolution of heat than is similarly caused in a small mass; and the
resulting difference of temperature will tend to produce more rapid
dissipation of heat. To this must be added the greater velocity of the
circulating currents which the intenser forces at work in larger
spheroids will produce--a contrast made still greater by the relatively
smaller retardation by friction to which the more voluminous currents
are exposed. In these causes, joined with causes previously indicated,
we may recognize a probable explanation of the otherwise anomalous fact
that the Sun, though having a thousand times the mass of Jupiter, has
yet reached as advanced a stage of concentration. For the force of
gravity in the Sun, which at his surface is some ten times that at the
surface of Jupiter, must expose his central parts to a pressure
relatively very intense; producing, during contraction, a relatively
rapid genesis of heat. And it is further to be remarked that, though the
circulating currents in the Sun have far greater distances to travel,
yet since his rotation is relatively so slow that the angular velocity
of his substance is but about one-sixtieth of that of Jupiter's
substance, the resulting obstacle to circulating currents is relatively
small, and the escape of heat far less retarded. Here, too, we may note
that in the co-operation of these factors, there seems a reason for the
greater concentration reached by Jupiter than by Saturn, though Saturn
is the elder as well as the smaller of the two; for at the same time
that the gravitative force in Jupiter is more than twice as great as in
Saturn, his velocity of rotation is very little greater, so that the
opposition of the centrifugal force to the centripetal is not much more
than half.

But now, not judging more than roughly of the effects of these several
factors, co-operating in various ways and degrees, some to aid
concentration and others to resist it, it is sufficiently manifest that,
other things equal, the larger nebulous spheroids, longer in losing
their heat, will more slowly reach high specific gravities; and that
where the contrasts in size are so immense as those between the greater
and the smaller planets, the smaller may have reached relatively high
specific gravities when the greater have reached but relatively low
ones. Further, it appears that such qualification of the process as
results from the more rapid genesis of heat in the larger masses, will
be countervailed where high velocity of rotation greatly impedes the
circulating currents. Thus interpreted then, the various specific
gravities of the planets may be held to furnish further evidences
supporting the Nebular Hypothesis.

       *       *       *       *       *

Increase of density and escape of heat are correlated phenomena, and
hence in the foregoing section, treating of the respective densities of
the celestial bodies in connexion with nebular condensation, much has
been said and implied respecting the accompanying genesis and
dissipation of heat. Quite apart, however, from the foregoing arguments
and inferences, there is to be noted the fact that in the present
temperatures of the celestial bodies at large we find additional
supports to the hypothesis; and these, too, of the most substantial
character. For if, as is implied above, heat must inevitably be
generated by the aggregation of diffused matter, we ought to find in all
the heavenly bodies, either present high temperatures or marks of past
high temperatures. This we do, in the places and in the degrees which
the hypothesis requires.

Observations showing that as we descend below the Earth's surface there
is a progressive increase of heat, joined with the conspicuous evidence
furnished by volcanoes, necessitate the conclusion that the temperature
is very high at great depths. Whether, as some believe, the interior of
the Earth is still molten, or whether, as Sir William Thomson contends,
it must be solid; there is agreement in the inference that its heat is
intense. And it has been further shown that the rate at which the
temperature increases on descending below the surface, is such as would
be found in a mass which had been cooling for an indefinite period. The
Moon, too, shows us, by its corrugations and its conspicuous extinct
volcanoes, that in it there has been a process of refrigeration and
contraction, like that which has gone on in the Earth. There is no
teleological explanation of these facts. The frequent destructions of
life by earthquakes and volcanoes, imply, rather, that it would have
been better had the Earth been created with a low internal temperature.
But if we contemplate the facts in connexion with the Nebular
Hypothesis, we see that this still-continued high internal heat is one
of its corollaries. The Earth must have passed through the gaseous and
the molten conditions before it became solid, and must for an almost
infinite period by its internal heat continue to bear evidence of this
origin.

The group of giant planets furnishes remarkable evidence. The _a priori_
inference drawn above, that great size joined with relatively high ratio
of centrifugal force to gravity must greatly retard aggregation, and
must thus, by checking the genesis and dissipation of heat, make the
process of cooling a slow one, has of late years received verifications
from inferences drawn _a posteriori_; so that now the current conclusion
among astronomers is that in physical condition the great planets are in
stages midway between that of the Earth and that of the Sun. The fact
that the centre of Jupiter's disc is twice or thrice as bright as his
periphery, joined with the facts that he seems to radiate more light
than is accounted for by reflection of the Sun's rays, and that his
spectrum shows the "red-star line", are taken as evidences of
luminosity; while the immense and rapid perturbations in his atmosphere,
far greater than could be caused by heat received from the Sun, as well
as the formation of spots analogous to those of the Sun, which also,
like those of the Sun, show a higher rate of rotation near the equator
than further from it, are held to imply high internal temperature. Thus
in Jupiter, as also in Saturn, we find states which, not admitting of
any teleological explanations (for they manifestly exclude the
possibility of life), admit of explanations derived from the Nebular
Hypothesis.

But the argument from temperature does not end here. There remains to be
noticed a more conspicuous and still more significant fact. If the Solar
System was produced by the concentration of diffused matter, which
evolved heat while gravitating into its present dense form; then there
is an obvious implication. Other things equal, the latest-formed mass
will be the latest in cooling--will, for an almost infinite time,
possess a greater heat than the earlier-formed ones. Other things equal,
the largest mass will, because of its superior aggregative force, become
hotter than the others, and radiate more intensely. Other things equal,
the largest mass, notwithstanding the higher temperature it reaches,
will, in consequence of its relatively small surface, be the slowest in
losing its evolved heat. And hence, if there is one mass which was not
only formed after the rest, but exceeds them enormously in size, it
follows that this one will reach an intensity of incandescence far
beyond that reached by the rest; and will continue in a state of intense
incandescence long after the rest have cooled. Such a mass we have in
the Sun. It is a corollary from the Nebular Hypothesis, that the matter
forming the Sun assumed its present integrated shape at a period much
more recent than that at which the planets became definite bodies. The
quantity of matter contained in the Sun is nearly five million times
that contained in the smallest planet, and above a thousand times that
contained in the largest. And while, from the enormous gravitative force
of his parts to their common centre, the evolution of heat has been
intense, the facilities of radiation have been relatively small. Hence
the still-continued high temperature. Just that condition of the central
body which is a necessary inference from the Nebular Hypothesis, we find
actually existing in the Sun.

[The paragraph which here follows, though it contains some questionable
propositions, I reproduce just as it stood when first published in 1858,
for reasons which will presently be apparent.]

It may be well to consider more closely, what is the probable condition
of the Sun's surface. Round the globe of incandescent molten substances,
thus conceived to form the visible body of the Sun [which in conformity
with the argument in a previous section, now transferred to the Addenda,
was inferred to be hollow and filled with gaseous matter at high
tension] there is known to exist a voluminous atmosphere: the inferior
brilliancy of the Sun's border, and the appearances during a total
eclipse, alike show this. What now must be the constitution of this
atmosphere? At a temperature approaching a thousand times that of molten
iron, which is the calculated temperature of the solar surface, very
many, if not all, of the substances we know as solid, would become
gaseous; and though the Sun's enormous attractive force must be a
powerful check on this tendency to assume the form of vapour, yet it
cannot be questioned that if the body of the Sun consists of molten
substances, some of them must be constantly undergoing evaporation. That
the dense gases thus continually being generated will form the entire
mass of the solar atmosphere, is not probable. If anything is to be
inferred, either from the Nebular Hypothesis, or from the analogies
supplied by the planets, it must be concluded that the outermost part of
the solar atmosphere consists of what are called permanent gases--gases
that are not condensible into fluid even at low temperatures. If we
consider what must have been the state of things here, when the surface
of the Earth was molten, we shall see that round the still molten
surface of the Sun, there probably exists a stratum of dense aeriform
matter, made up of sublimed metals and metallic compounds, and above
this a stratum of comparatively rare medium analogous to air. What now
will happen with these two strata? Did they both consist of permanent
gases, they could not remain separate: according to a well-known law,
they would eventually form a homogeneous mixture. But this will by no
means happen when the lower stratum consists of matters that are gaseous
only at excessively high temperatures. Given off from a molten surface,
ascending, expanding, and cooling, these will presently reach a limit of
elevation above which they cannot exist as vapour, but must condense and
precipitate. Meanwhile the upper stratum, habitually charged with its
quantum of these denser matters, as our air with its quantum of water,
and ready to deposit them on any depression of temperature, must be
habitually unable to take up any more of the lower stratum; and
therefore this lower stratum will remain quite distinct from it.[20]

       *       *       *       *       *

Considered in their _ensemble_, the several groups of evidences assigned
amount almost to proof. We have seen that, when critically examined,
the speculations of late years current respecting the nature of the
nebulæ, commit their promulgators to sundry absurdities; while, on the
other hand, we see that the various appearances these nebulæ present,
are explicable as different stages in the precipitation and aggregation
of diffused matter. We find that the immense majority of comets (_i.e._
omitting the periodic ones), by their physical constitution, their
immensely-extended and variously-directed paths, the distribution of
those paths, and their manifest structural relation to the Solar System,
bear testimony to the past existence of that system in a nebulous form.
Not only do those obvious peculiarities in the motions of the planets
which first suggested the Nebular Hypothesis, supply proofs of it, but
on closer examination we discover, in the slightly-diverging
inclinations of their orbits, in their various rates of rotation, and
their differently-directed axes of rotation, that the planets yield us
yet further testimony; while the satellites, by sundry traits, and
especially by their occurrence in greater or less abundance where the
hypothesis implies greater or less abundance, confirm this testimony. By
tracing out the process of planetary condensation, we are led to
conclusions respecting the physical states of planets which explain
their anomalous specific gravities. Once more, it turns out that what is
inferable from the Nebular Hypothesis respecting the temperatures of
celestial bodies, is just what observation establishes; and that both
the absolute and the relative temperatures of the Sun and planets are
thus accounted for. When we contemplate these various evidences in their
totality--when we observe that, by the Nebular Hypothesis, the leading
phenomena of the Solar System, and the heavens in general, are
explicable; and when, on the other hand, we consider that the current
cosmogony is not only without a single fact to stand on, but is at
variance with all our positive knowledge of Nature, we see that the
proof becomes overwhelming.

It remains only to point out that while the genesis of the Solar System,
and of countless other systems like it, is thus rendered comprehensible,
the ultimate mystery continues as great as ever. The problem of
existence is not solved: it is simply removed further back. The Nebular
Hypothesis throws no light on the origin of diffused matter; and
diffused matter as much needs accounting for as concrete matter. The
genesis of an atom is not easier to conceive than the genesis of a
planet. Nay, indeed, so far from making the Universe less a mystery than
before, it makes it a greater mystery. Creation by manufacture is a much
lower thing than creation by evolution. A man can put together a
machine; but he cannot make a machine develop itself. That our
harmonious universe once existed potentially as formless diffused
matter, and has slowly grown into its present organized state, is a far
more astonishing fact than would have been its formation after the
artificial method vulgarly supposed. Those who hold it legitimate to
argue from phenomena to noumena, may rightly contend that the Nebular
Hypothesis implies a First Cause as much transcending "the mechanical
God of Paley," as this does the fetish of the savage.

FOOTNOTES:

[Footnote 11: _Cosmos._ (Seventh Edition.) Vol. i. pp. 79, 80.]

[Footnote 12: Since the publication of this essay the late Mr. R. A.
Proctor has given various further reasons for the conclusion that the
nebulæ belong to our own sidereal system. The opposite conclusion,
contested throughout the foregoing section, has now been tacitly
abandoned.]

[Footnote 13: Any objection made to the extreme tenuity this involves,
is met by the calculation of Newton, who proved that were a spherical
inch of air removed four thousand miles from the Earth, it would expand
into a sphere more than filling the orbit of Saturn.]

[Footnote 14: A reference may fitly be made here to a reason given by
Mons. Babinet for rejection of the Nebular Hypothesis. He has calculated
that taking the existing Sun, with its observed angular velocity, its
substance, if expanded so as to fill the orbit of Neptune, would have
nothing approaching the angular velocity which the time of revolution of
that planet implies. The assumption he makes is inadmissible. He
supposes that all parts of the nebulous spheroid when it filled
Neptune's orbit, had the same angular velocities. But the process of
nebular condensation as indicated above, implies that the remoter
flocculi of nebulous matter, later in reaching the central mass, and
forming its peripheral portions, will acquire, during their longer
journeys towards it, greater velocities. An inspection of one of the
spiral nebulæ, as 51st or 99th Messier, at once shows that the outlying
portions when they reach the nucleus, will form an equatorial belt
moving round the common centre more rapidly than the rest. Thus the
central parts will have small angular velocities, while there will be
increasing angular velocities of parts increasingly remote from the
centre. And while the density of the spheroid continues small, fluid
friction will scarcely at all change these differences.

A like criticism may, I think, be passed on an opinion expressed by
Prof. Newcomb. He says:--"When the contraction [of the nebulous
spheroid] had gone so far that the centrifugal and attracting forces
nearly balanced each other at the outer equatorial limit of the mass,
the result would have been that contraction in the direction of the
equator would cease entirely, and be confined to the polar regions, each
particle dropping, not towards the sun, but towards the plane of the
solar equator. Thus, we should have a constant flattening of the
spheroidal atmosphere until it was reduced to a thin flat disk. This
disk might then separate itself into rings, which would form planets in
much the same way that Laplace supposed. But there would probably be no
marked difference in the age of the planets." (_Popular Astronomy_,
p. 512.) Now this conclusion assumes, like that of M. Babinet, that all
parts of the nebulous spheroid had equal angular velocities. If, as
above contended, it is inferable from the process by which a nebulous
spheroid was formed, that its outer portions revolved with greater
angular velocities than its inner; then the inference which Prof.
Newcomb draws is not necessitated.]

[Footnote 15: It is true that since this essay was written reasons have
been given for concluding that comets consist of swarms of meteors
enveloped in aeriform matter. Very possibly this is the constitution of
the periodic comets which, approximating their orbits to the plane of
the Solar System, form established parts of the System, and which, as
will be hereafter indicated, have probably a quite different origin.]

[Footnote 16: Though this rule fails at the periphery of the Solar
System, yet it fails only where the axis of rotation, instead of being
almost perpendicular to the orbit-plane, is very little inclined to it;
and where, therefore, the forces tending to produce the congruity of
motions were but little operative.]

[Footnote 17: It is true that, as expressed by him, these propositions
of Laplace are not all beyond dispute. An astronomer of the highest
authority, who has favoured me with some criticisms on this essay,
alleges that instead of a nebulous ring rupturing at one point, and
collapsing into a single mass, "all probability would be in favour of
its breaking up into many masses." This alternative result certainly
seems the more likely. But granting that a nebulous ring would break up
into many masses, it may still be contended that, since the chances are
infinity to one against these being of equal sizes _and_ equidistant,
they could not remain evenly distributed round their orbit. This annular
chain of gaseous masses would break up into groups of masses; these
groups would eventually aggregate into larger groups; and the final
result would be the formation of a single mass. I have put the question
to an astronomer scarcely second in authority to the one above referred
to, and he agrees that this would probably be the process.]

[Footnote 18: The comparative statement here given differs, slightly in
most cases and in one case largely, from the statement included in this
essay as originally published in 1858. As then given the table ran
thus:--

   Mercury.   1/362
   Venus.     1/282
   Earth.     1/289   1 Satellite.
   Mars.      1/326
   Jupiter.   1/14    4 Satellites.
   Saturn.    1/6·2   8 Satellites, and three rings.
   Uranus.    1/9     4 (or 6 according to Herschel).

The calculations ending with these figures were made while the Sun's
distance was still estimated at 95 millions of miles. Of course the
reduction afterwards established in the estimated distance, entailing,
as it did, changes in the factors which entered into the calculations,
affected the results; and, though it was unlikely that the relations
stated would be materially changed, it was needful to have the
calculations made afresh. Mr. Lynn has been good enough to undertake
this task, and the figures given in the text are his. In the case of
Mars a large error in my calculation had arisen from accepting Arago's
statement of his density (0·95), which proves to be something like
double what it should be. Here a curious incident may be named. When, in
1877, it was discovered that Mars has two satellites, though, according
to my hypothesis, it seemed that he should have none, my faith in it
received a shock; and since that time I have occasionally considered
whether the fact is in any way reconcilable with the hypothesis. But now
the proof afforded by Mr. Lynn that my calculation contained a wrong
factor, disposes of the difficulty--nay, changes the objection to a
verification. It turns out that, according to the hypothesis, Mars
_ought_ to have satellites; and, further, that he ought to have a number
intermediate between 1 and 4.]

[Footnote 19: Since this paragraph was first published, the discovery
that Mars has two satellites revolving round him in periods shorter than
that of his rotation, has shown that the implication on which Laplace
here insists is general only, and not absolute. Were it a necessary
assumption that all parts of a concentrating nebulous spheroid revolve
with the same angular velocities, the exception would appear an
inexplicable one; but if, as suggested in a preceding section, it is
inferable from the process of formation of a nebulous spheroid, that its
outer strata will move round the general axis with higher angular
velocities than the inner ones, there follows a possible interpretation.
Though, during the earlier stages of concentration, while the nebulous
matter, and especially its peripheral portions, are very rare, the
effects of fluid-friction will be too small to change greatly such
differences of angular velocities as exist; yet, when concentration has
reached its last stages, and the matter is passing from the gaseous into
the liquid and solid states, and when also the convection-currents have
become common to the whole mass (which they probably at first are not),
the angular velocity of the peripheral portion will gradually be
assimilated to that of the interior; and it becomes comprehensible that
in the case of Mars the peripheral portion, more and more dragged back
by the internal mass, lost part of its velocity during the interval
between the formation of the innermost satellite and the arrival at the
final form.]

[Footnote 20: I was about to suppress part of the above paragraph,
written before the science of solar physics had taken shape, because of
certain physical difficulties which stand in the way of its argument,
when, on looking into recent astronomical works, I found that the
hypothesis it sets forth respecting the Sun's structure has kinships to
the several hypotheses since set forth by Zöllner, Faye, and Young. I
have therefore decided to let it stand as it originally did.

The contemplated partial suppression just named, was prompted by
recognition of the truth that to effect mechanical stability the gaseous
interior of the Sun must have a density at least equal to that of the
molten shell (greater, indeed, at the centre); and this seems to imply a
specific gravity higher than that which he possesses. It may, indeed, be
that the unknown elements which spectrum analysis shows to exist in the
Sun, are metals of very low specific gravities, and that, existing in
large proportion with other of the lighter metals, they may form a
molten shell not denser than is implied by the facts. But this can be
regarded as nothing more than a possibility.

No need, however, has arisen for either relinquishing or holding but
loosely the associated conclusions respecting the constitution of the
photosphere and its envelope. Widely speculative as seemed these
suggested corollaries from the Nebular Hypothesis when set forth in
1858, and quite at variance with the beliefs then current, they proved
to be not ill-founded. At the close of 1859, there came the discoveries
of Kirchhoff, proving the existence of various metallic vapours in the
Sun's atmosphere.]




ADDENDA.


Speculative as is much of the foregoing essay, it appears undesirable to
include in it anything still more speculative. For this reason I have
decided to set forth separately some views concerning the genesis of the
so-called elements during nebular condensation, and concerning the
accompanying physical effects. At the same time it has seemed best to
detach from the essay some of the more debatable conclusions originally
contained in it; so that its general argument may not be needlessly
implicated with them. These new portions, together with the old portions
which re-appear more or less modified, I here append in a series of
notes.


NOTE I. For the belief that the so-called elements are compound there
are both special reasons and general reasons. Among the special may be
named the parallelism between allotropy and isomerism; the numerous
lines in the spectrum of each element; and the cyclical law of Newlands
and Mendeljeff. Of the more general reasons, which, as distinguished
from these chemical or chemico-physical ones, may fitly be called
cosmical, the following are the chief.

The general law of evolution, if it does not actually involve the
conclusion that the so-called elements are compounds, yet affords _a
priori_ ground for suspecting that they are such. The implication is
that, while the matter composing the Solar System has progressed
physically from that relatively-homogeneous state which it had as a
nebula to that relatively-heterogeneous state presented by Sun, planets,
and satellites, it has also progressed chemically, from the
relatively-homogeneous state in which it was composed of one or a few
types of matter, to that relatively-heterogeneous state in which it is
composed of many types of matter very diverse in their properties. This
deduction from the law which holds throughout the cosmos as now known to
us, would have much weight even were it unsupported by induction; but a
survey of chemical phenomena at large discloses several groups of
inductive evidences supporting it.

The first is that since the cooling of the Earth reached an advanced
stage, the components of its crust have been ever increasing in
heterogeneity. When the so-called elements, originally existing in a
dissociated state, united into oxides, acids, and other binary
compounds, the total number of different substances was immensely
augmented, the new substances were more complex than the old, and their
properties were more varied. That is, the assemblage became more
heterogeneous in its kinds, in the composition of each kind, and in the
range of chemical characters. When, at a later period, there arose salts
and other compounds of similar degrees of complexity, there was again an
increase of heterogeneity, alike in the aggregate and in its members.
And when, still later, matters classed as organic became possible, the
multiformity was yet further augmented in kindred ways. If, then,
chemical evolution, so far as we can trace it, has been from the
homogeneous to the heterogeneous, may we not fairly suppose that it has
been so from the beginning? If, from late stages in the Earth's history,
we run back, and find the lines of chemical evolution continually
converging, until they bring us to bodies which we cannot decompose, may
we not suspect that, could we run back these lines still further, we
should come to still decreasing heterogeneity in the number and nature
of the substances, until we reached something like homogeneity?

A parallel argument may be derived from consideration of the affinities
and stabilities of chemical compounds. Beginning with the complex
nitrogenous bodies out of which living things are formed, and which, in
the history of the Earth, are the most modern, at the same time that
they are the most heterogeneous, we see that the affinities and
stabilities of these are extremely small. Their molecules do not enter
bodily into union with those of other substances so as to form more
complex compounds still, and their components often fail to hold
together under ordinary conditions. A stage lower in degree of
composition we come to the vast assemblage of oxy-hydro-carbons, numbers
of which show many and decided affinities, and are stable at common
temperatures. Passing to the inorganic group, we are shown by the salts
&c. strong affinities between their components and unions which are, in
many cases, not very easily broken. And then when we come to the oxides,
acids, and other binary compounds, we see that in many cases the
elements of which they are formed, when brought into the presence of one
another under favourable conditions, unite with violence; and that many
of their unions cannot be dissolved by heat alone. If, then, as we go
back from the most modern and most complex substances to the most
ancient and simplest substances, we see, on the average, a great
increase in affinity and stability, it results that if the same law
holds with the simplest substances known to us, the components of these,
if they are compound, may be assumed to have united with affinities far
more intense than any we have experience of, and to cling together with
tenacities far exceeding the tenacities with which chemistry acquaints
us. Hence the existence of a class of substances which are
undecomposable and therefore seem simple, appears to be an implication;
and the corollary is that these were formed during early stages of
terrestrial concentration, under conditions of heat and pressure which
we cannot now parallel.

Yet another support for the belief that the so-called elements are
compounds, is derived from a comparison of them, considered as an
aggregate ascending in their molecular weights, with the aggregate of
bodies known to be compound, similarly considered in their ascending
molecular weights. Contrast the binary compounds as a class with the
quaternary compounds as a class. The molecules constituting oxides
(whether alkaline or acid or neutral) chlorides, sulphurets, &c. are
relatively small; and, combining with great avidity, form stable
compounds. On the other hand, the molecules constituting nitrogenous
bodies are relatively vast and are chemically inert; and such
combinations as their simpler types enter into, cannot withstand
disturbing forces. Now a like difference is seen if we contrast with one
another the so-called elements. Those of relatively-low molecular
weights--oxygen, hydrogen, potassium, sodium, &c.,--show great readiness
to unite among themselves; and, indeed, many of them cannot be prevented
from uniting under ordinary conditions. Contrariwise, under ordinary
conditions the substances of high molecular weights--the "noble
metals"--are indifferent to other substances; and such compounds as they
do form under conditions specially adjusted, are easily destroyed. Thus
as, among the bodies we know to be compound, increasing molecular weight
is associated with the appearance of certain characters, and as, among
the bodies we class as simple, increasing molecular weight is
associated with the appearance of similar characters, the composite
nature of the elements is in another way pointed to.

There has to be added one further class of phenomena, congruous with
those above named, which here specially concerns us. Looking generally
at chemical unions, we see that the heat evolved usually decreases as
the degree of composition, and consequent massiveness, of the molecules,
increases. In the first place, we have the fact that during the
formation of simple compounds the heat evolved is much greater than that
which is evolved during the formation of complex compounds: the
elements, when uniting with one another, usually give out much heat;
while, when the compounds they form are recompounded, but little heat is
given out; and, as shown by the experiments of Prof. Andrews, the heat
given out during the union of acids and bases is habitually smaller
where the molecular weight of the base is greater. Then, in the second
place, we see that among the elements themselves, the unions of those
having low molecular weights result in far more heat than do the unions
of those having high molecular weights. If we proceed on the supposition
that the so-called elements are compounds, and if this law, if not
universal, holds of undecomposable substances as of decomposable, then
there are two implications. The one is that those compoundings and
recompoundings by which the elements were formed, must have been
accompanied by degrees of heat exceeding any degrees of heat known to
us. The other is that among these compoundings and recompoundings
themselves, those by which the small-moleculed elements were formed
produced more intense heat than those by which the large-moleculed
elements were formed: the elements formed by the final recompoundings
being necessarily later in origin, and at the same time less stable,
than the earlier-formed ones.


NOTE II. May we from these propositions, and especially from the last,
draw any conclusions respecting the evolution of heat during nebular
condensation? And do such conclusions affect in any way the conclusions
now current?

In the first place, it seems inferable from physico-chemical facts at
large, that only through the instrumentality of those combinations which
formed the elements, did the concentration of diffused nebulous matter
into concrete masses become possible. If we remember that hydrogen and
oxygen in their uncombined states oppose, the one an insuperable and the
other an almost insuperable, resistance to liquefaction, while when
combined the compound assumes the liquid state with facility, we may
suspect that in like manner the simpler types of matter out of which the
elements were formed, could not have been reduced even to such degrees
of density as the known gases show us, without what we may call
proto-chemical unions: the implication being that after the heat
resulting from each of such proto-chemical unions had escaped, mutual
gravitation of the parts was able to produce further condensation of the
nebulous mass.

If we thus distinguish between the two sources of heat accompanying
nebular condensation--the heat due to proto-chemical combinations and
that due to the contraction caused by gravitation (both of them,
however, being interpretable as consequent on loss of motion), it may be
inferred that they take different shares during the earlier and during
the later stages of aggregation. It seems probable that while the
diffusion is great and the force of mutual gravitation small, the chief
source of heat is combination of units of matter, simpler than any known
to us, into such units of matter as those we know; while, conversely,
when there has been reached close aggregation, the chief source of heat
is gravitation, with consequent pressure and gradual contraction.
Supposing this to be so, let us ask what may be inferred. If at the time
when the nebulous spheroid from which the Solar System resulted, filled
the orbit of Neptune, it had reached such a degree of density as
enabled those units of matter which compose the sodium molecules to
enter into combination; and if, in conformity with the analogies above
indicated, the heat evolved by this proto-chemical combination was great
compared with the heats evolved by the chemical combinations known to
us; the implication is that the nebulous spheroid, in the course of its
contraction, would have to get rid of a much larger quantity of heat
than it would, did it commence at any ordinary temperature and had only
to lose the heat consequent on contraction. That is to say, in
estimating the past period during which solar emission of heat has been
going on at a high rate, much must depend on the initial temperature
assumed; and this may have been rendered intense by the proto-chemical
changes which took place in early stages.[21]

Respecting the future duration of the solar heat, there must also be
differences between the estimates made according as we do or do not take
into account the proto-chemical changes which possibly have still to
take place. True as it may be that the quantity of heat to be emitted
is measured by the quantity of motion to be lost, and that this must be
the same whether the approximation of the molecules is effected by
chemical unions, or by mutual gravitation, or by both; yet, evidently,
everything must turn on the degree of condensation supposed to be
eventually reached; and this must in large measure depend on the natures
of the substances eventually formed. Though, by spectrum-analysis,
platinum has recently been detected in the solar atmosphere, it seems
clear that the metals of low molecular weights greatly predominate; and
supposing the foregoing arguments to be valid, it may be inferred, as
not improbable, that the compoundings and recompoundings by which the
heavy-moleculed elements are produced, not hitherto possible in large
measure, will hereafter take place; and that, as a result, the Sun's
density will finally become very great in comparison with what it is
now. I say "not hitherto possible in large measure", because it is a
feasible supposition that they may be formed, and can continue to exist,
only in certain outer parts of the Solar mass, where the pressure is
sufficiently great while the heat is not too great. And if this be so,
the implication is that the interior body of the Sun, higher in
temperature than its peripheral layers, may consist wholly of the metals
of low atomic weights, and that this may be a part cause of his low
specific gravity; and a further implication is that when, in course of
time, the internal temperature falls, the heavy-moleculed elements, as
they severally become capable of existing in it, may arise: the
formation of each having an evolution of heat as its concomitant.[22] If
so, it would seem to follow that the amount of heat to be emitted by
the Sun, and the length of the period during which the emission will go
on, must be taken as much greater than if the Sun is supposed to be
permanently constituted of the elements now predominating in him, and to
be capable of only that degree of condensation which such composition
permits.


NOTE III. Are the internal structures of celestial bodies all the same,
or do they differ? And if they differ, can we, from the process of
nebular condensation, infer the conditions under which they assume one
or other character? In the foregoing essay as originally published,
these questions were discussed; and though the conclusions reached
cannot be sustained in the form given to them, they foreshadow
conclusions which may, perhaps, be sustained. Referring to the
conceivable causes of unlike specific gravities in the members of the
solar system, it was said that these might be--

     "1. Differences between the kinds of matter or matters composing
     them. 2. Differences between the quantities of matter; for, other
     things equal, the mutual gravitation of atoms will make a large
     mass denser than a small one. 3. Differences between the
     structures: the masses being either solid or liquid throughout, or
     having central cavities filled with elastic aëriform substance. Of
     these three conceivable causes, that commonly assigned is the
     first, more or less modified by the second."

Written as this was before spectrum-analysis had made its disclosures,
no notice could of course be taken of the way in which these conflict
with the first of the foregoing suppositions; but after pointing out
other objections to it the argument continued thus:--

     "However, spite of these difficulties, the current hypothesis is,
     that the Sun and planets, inclusive of the Earth, are either solid
     or liquid, or have solid crusts with liquid nuclei."[23]

After saying that the familiarity of this hypothesis must not delude us
into uncritical acceptance of it, but that if any other hypothesis is
physically possible it may reasonably be entertained, it was argued that
by tracing out the process of condensation in a nebulous spheroid, we
are led to infer the eventual formation of a molten shell with a nucleus
consisting of gaseous matter at high tension. The paragraph which then
follows runs thus:--

     "But what," it may be asked, "will become of this gaseous nucleus
     when exposed to the enormous gravitative pressure of a shell some
     thousands of miles thick? How can aeriform matter withstand such a
     pressure?" Very readily. It has been proved that, even when the
     heat generated by compression is allowed to escape, some gases
     remain uncondensible by any force we can produce. An unsuccessful
     attempt lately made in Vienna to liquify oxygen, clearly shows this
     enormous resistance. The steel piston employed was literally
     shortened by the pressure used; and yet the gas remained
     unliquified! If, then, the expansive force is thus immense when the
     heat evolved is dissipated, what must it be when that heat is in
     great measure detained, as in the case we are considering? Indeed
     the experiences of M. Cagniard de Latour have shown that gases may,
     under pressure, acquire the density of liquids while retaining the
     aeriform state, provided the temperature continues extremely high.
     In such a case, every addition to the heat is an addition to the
     repulsive power of the atoms: the increased pressure itself
     generates an increased ability to resist; and this remains true to
     whatever extent the compression is carried. Indeed it is a
     corollary from the persistence of force that if, under increasing
     pressure, a gas retains all the heat evolved, its resisting force
     is _absolutely unlimited_. Hence the internal planetary structure
     we have described is as physically stable a one as that commonly
     assumed."

Had this paragraph, and the subsequent paragraphs, been written five
years later, when Prof. Andrews had published an account of his
researches, the propositions they contain, while rendered more specific
and at the same time more defensible, would perhaps have been freed from
the erroneous implication that the internal structure indicated is an
universal one. Let us, while guided by Prof. Andrews' results, consider
what would probably be the successive changes in a condensing nebulous
spheroid.

Prof. Andrews has shown that for each kind of gaseous matter there is a
temperature above which no amount of pressure can cause liquefaction.
The remark, made _a priori_ in the above extract, "that if, under
increasing pressure, a gas retains all the heat evolved, its
resisting force is _absolutely unlimited_", harmonizes with the
inductively-reached result that if the temperature is not lowered to its
"critical point" a gas does not liquify, however great the force
applied. At the same time Prof. Andrews' experiments imply that,
supposing the temperature to be lowered to the point at which
liquefaction becomes possible, then liquefaction will take place where
there is first reached the required pressure. What are the corollaries
in relation to concentrating nebulous spheroids?

Assume a spheroid of such size as will form one of the inferior planets,
and consisting externally of a voluminous, cloudy atmosphere composed of
the less condensible elements, and internally of metallic gases: such
internal gases being kept by convection-currents at temperatures not
very widely differing. And assume that continuous radiation has brought
the internal mass of metallic gases down to the critical point of the
most condensible. May we not say that there is a size of the spheroid
such that the pressure will not be great enough to produce liquefaction
at any other place than the centre? or, in other words, that in the
process of decreasing temperature and increasing pressure, the centre
will be the place at which the combined conditions of pressure and
temperature will be first reached? If so, liquefaction, commencing at
the centre, will spread thence to the periphery; and, in virtue of the
law that solids have higher melting points under pressure than when
free, it may be that solidification will similarly, at a later stage,
begin at the centre and progress outwards: eventually producing, in that
case, a state such as Sir William Thomson alleges exists in the Earth.
But now suppose that instead of such a spheroid, we assume one of, say,
twenty or thirty times the mass; what will then happen? Notwithstanding
convection-currents, the temperature at the centre must always be
higher than elsewhere; and in the process of cooling the "critical
point" of temperature will sooner be reached in the outer parts. Though
the requisite pressure will not exist near the surface, there is
evidently, in a large spheroid, a depth below the surface at which the
pressure will be great enough, if the temperature is sufficiently low.
Hence it is inferable that somewhere between centre and surface in the
supposed larger spheroid, there will arise that state described by Prof.
Andrews, in which "flickering striæ" of liquid float in gaseous matter
of equal density. And it may be inferred that gradually, as the process
goes on, these striæ will become more abundant while the gaseous
interspaces diminish; until, eventually, the liquid becomes continuous.
Thus there will result a molten shell containing a gaseous nucleus
equally dense with itself at their surface of contact and more dense at
the centre--a molten shell which will slowly thicken by additions to
both exterior and interior.

That a solid crust will eventually form on this molten shell may be
reasonably concluded. To the demurrer that solidification cannot
commence at the surface, because the solids formed would sink, there are
two replies. The first is that various metals expand while solidifying,
and therefore would float. The second is that since the envelope of the
supposed spheroid would consist of the gases and non-metallic elements,
compounds of these with the metals and with one another would
continually accumulate on the molten shell; and the crust, consisting of
oxides, chlorides, sulphurets, and the rest, having much less specific
gravity than the molten shell, would be readily supported by it.

Clearly a planet thus constituted would be in an unstable state. Always
it would remain liable to a catastrophe resulting from change in its
gaseous nucleus. If, under some condition of pressure and temperature
eventually reached, the components of this suddenly entered into one of
those proto-chemical combinations forming a new element, there might
result an explosion capable of shattering the entire planet, and
propelling its fragments in all directions with high velocities. If the
hypothetical planet between Jupiter and Mars was intermediate in size as
in position, it would apparently fulfil the conditions under which such
a catastrophe might occur.


NOTE IV. The argument set forth in the foregoing note, is in part
designed to introduce a question which seems to require
re-consideration--the origin of the minor planets or planetoids. The
hypothesis of Olbers, as propounded by him, implied that the disruption
of the assumed planet between Mars and Jupiter had taken place at no
very remote period in the past; and this implication was shown to be
inadmissible by the discovery that there exists no such point of
intersection of the orbits of the planetoids as the hypothesis requires.
The inquiry whether, in the past, there was any nearer approach to a
point of intersection than at present, having resulted in a negative, it
is held that the hypothesis must be abandoned. It is, however, admitted
that the mutual perturbations of the planetoids themselves would
suffice, in the course of some millions of years, to destroy all traces
of a place of intersection of their orbits, if it once existed. But if
this be admitted why need the hypothesis be abandoned? Given such
duration of the Solar System as is currently assumed, there seems no
reason why lapse of a few millions of years should present any
difficulty. The explosion may as well have taken place ten million years
ago as at any more recent period. And whoever grants this must grant
that the probability of the hypothesis has to be estimated from other
data.

As a preliminary to closer consideration, let us ask what may be
inferred from the rate of discovery of the planetoids, and from the
sizes of those most recently discovered. In 1878, Prof. Newcomb, arguing
that "the preponderance of evidence is on the side of the number and
magnitude being limited", says that "the newly discovered ones" "do not
seem, on the average, to be materially smaller than those which were
discovered ten years ago"; and further that "the new ones will probably
be found to grow decidedly rare before another hundred are discovered".
Now, inspection of the tables contained in the just-published fourth
edition of Chambers' _Descriptive Astronomy_ (vol. I) shows that whereas
the planetoids discovered in 1868 (the year Prof. Newcomb singles out
for comparison) have an average magnitude of 11·56 those discovered last
year (1888) have an average magnitude of 12·43. Further, it is
observable that though more than ninety have been discovered since Prof.
Newcomb wrote, they have by no means become rare: the year 1888 having
added ten to the list, and having therefore maintained the average rate
of the preceding ten years. If, then, the indications Prof. Newcomb
names, had they arisen, would have implied a limitation of the number,
these opposite indications imply that the number is unlimited. The
reasonable conclusion appears to be that these minor planets are to be
counted not by hundreds but by thousands; that more powerful telescopes
will go on revealing still smaller ones; and that additions to the list
will cease only when the smallness ends in invisibility.

Commencing now to scrutinize the two hypotheses respecting the genesis
of these multitudinous bodies, I may first remark concerning that of
Laplace, that he might possibly not have propounded it had he known that
instead of four such bodies there are hundreds, if not thousands. The
supposition that they resulted from the breaking up of a nebulous ring
into numerous small portions, instead of its collapse into one mass,
might not, in such case, have seemed to him so probable. It would have
appeared still less probable had he been aware of all that has since
been discovered concerning the wide differences of the orbits in size,
their various and often great eccentricities, and their various and
often great inclinations. Let us look at these and other incongruous
traits of them.

(1.) Between the greatest and least mean distances of the planetoids
there is a space of 200 millions of miles; so that the whole of the
Earth's orbit might be placed between the limits of the zone occupied,
and leave 7 millions of miles on either side: add to which that the
widest excursions of the planetoids occupy a zone of 270 millions of
miles. Had the rings from which Mercury, Venus, and the Earth were
formed been one-sixth of the smaller width or one-ninth of the greater,
they would have united: there would have been no nebulous rings at all,
but a continuous disk. Nay more, since one of the planetoids trenches
upon the orbit of Mars, it follows that the nebulous ring out of which
the planetoids were formed must have overlapped that out of which Mars
was formed. How do these implications consist with the nebular
hypothesis? (2.) The tacit assumption usually made is that the different
parts of a nebulous ring have the same angular velocities. Though this
assumption may not be strictly true, yet it seems scarcely likely that
it is so widely untrue as it would be had the inner part of the ring an
angular velocity nearly thrice that of the outer. Yet this is implied.
While the period of Thule is 8.8 years, the period of Medusa is 3·1
years. (3.) The eccentricity of Jupiter's orbit is 0·04816, and the
eccentricity of Mars' orbit is 0·09311. Estimated by groups of the first
found and last found of the planetoids, the average eccentricity of the
assemblage is about three times that of Jupiter and more than one and a
half times that of Mars; and among the members of the assemblage
themselves, some have an eccentricity thirty-five times that of others.
How came this nebulous zone, out of which it is supposed the planetoids
arose, to have originated eccentricities so divergent from one another
as well as from those of the neighbouring planets? (4.) A like question
may be asked respecting the inclinations of the orbits. The average
inclination of the planetoid-orbits is four times the inclination of
Mars' orbit and six times the inclination of Jupiter's orbit; and among
the planetoid-orbits themselves the inclinations of some are fifty times
those of others. How are all these differences to be accounted for on
the hypothesis of genesis from a nebulous ring? (5.) Much greater
becomes the difficulty on inquiring how these extremely unlike
eccentricities and inclinations came to co-exist before the parts of the
nebulous ring separated, and how they survived after the separation.
Were all the great eccentricities displayed by the outermost members of
the group, and the small by the innermost members, and were the
inclinations so distributed that the orbits having much belonged to one
part of the group, and those having little to another part of the group;
the difficulty of explanation might not be insuperable. But the
arrangement is by no means this. The orbits are, to use an expressive
word, miscellaneously jumbled. Hence, if we go back to the nebulous
ring, there presents itself the question,--How came each
planetoid-forming portion of nebulous matter, when it gathered itself
together and separated, to have a motion round the Sun differing so much
from the motions of its neighbours in eccentricity and inclination? And
there presents itself the further question,--How, during the time when
it was concentrating into a planetoid, did it manage to jostle its way
through all the differently-moving like masses of nebulous matter, and
yet to preserve its individuality? Answers to these questions are, it
seems to me, not even imaginable.

       *       *       *       *       *

Turn we now to the alternative hypothesis. During revision of the
foregoing essay, in preparation for that edition of the volume
containing it which was published in 1883, there occurred the thought
that some light on the origin of the planetoids ought to be obtained by
study of their distributions and movements. If, as Olbers supposed,
they resulted from the bursting of a planet once revolving in the region
they occupy, the implications are:--first, that the fragments must be
most abundant in the space immediately about the original orbit, and
less abundant far away from it; second, that the large fragments must be
relatively few, while of smaller fragments the numbers will increase as
the sizes decrease; third, that as some among the smaller fragments will
be propelled further than any of the larger, the widest deviations in
mean distance from the mean distance of the original planet, will be
presented by the smallest members of the assemblage; and fourth, that
the orbits differing most from the rest in eccentricity and in
inclination, will be among those of these smallest members. In the
fourth edition of Chambers's _Handbook of Descriptive and Practical
Astronomy_ (the first volume of which has just been issued) there is a
list of the elements (extracted and adapted from the _Berliner
Astronomisches Jahrbuch_ for 1890) of all the small planets (281 in
number) which had been discovered up to the end of 1888. The apparent
brightness, as expressed in equivalent star-magnitudes, is the only
index we have to the probable comparative sizes of by far the largest
number of the planetoids: the exceptions being among those first
discovered. Thus much premised, let us take the above points in order.
(1) There is a region lying between 2·50 and 2·80 (in terms of the
Earth's mean distance from the Sun) where the planetoids are found in
maximum abundance. The mean between these extremes, 2·65, is nearly the
same as the average of the distances of the four largest and
earliest-known of these bodies, which amounts to 2·64. May we not say
that the thick clustering about this distance (which is, however, rather
less than that assigned for the original planet by Bode's empirical
law), in contrast with the wide scattering of the comparatively few
whose distances are little more than 2 or exceed 3, is a fact in
accordance with the hypothesis in question?[24] (2) Any table which
gives the apparent magnitudes of the planetoids, shows at once how much
the number of the smaller members of the assemblage exceeds that of
those which are comparatively large; and every succeeding year has
emphasized this contrast more strongly. Only one of them (Vesta) exceeds
in brightness the seventh star-magnitude, while one other (Ceres) is
between the seventh and eighth, and a third (Pallas) is above the
eighth; but between the eighth and ninth there are six; between the
ninth and tenth, twenty; between the tenth and eleventh, fifty-five;
below the eleventh a much larger number is known, and the number
existing is probably far greater,--a conclusion we cannot doubt when the
difficulty of finding the very faint members of the family, visible only
in the largest telescopes, is considered. (3) Kindred evidence is
furnished if we broadly contrast their mean distances. Out of the 13
largest planetoids whose apparent brightnesses exceed that of a star of
the 9·5 magnitude, there is not one having a mean distance that exceeds
3. Of those having magnitudes at least 9·5 and smaller than 10, there
are 15; and of these one only has a mean distance greater than 3. Of
those between 10 and 10·5 there are 17; and of these also there is one
exceeding 3 in mean distance. In the next group there are 37, and of
these 5 have this great mean distance. The next group, 48, contains 12
such; the next, 47, contains 13 such. Of those of the twelfth magnitude
and fainter, 72 planetoids have been discovered, and of those of them
of which the orbits have been computed, no fewer than 23 have a mean
distance exceeding 3 in terms of the Earth's. It is evident from this
how comparatively erratic are the fainter members of the extensive
family with which we are dealing. (4) To illustrate the next point, it
may be noted that among the planetoids whose sizes have been
approximately measured, the orbits of the two largest, Vesta and Ceres,
have eccentricities falling between .05 and .10, whilst the orbits of
the two smallest, Menippe and Eva, have eccentricities falling between
.20 and .25, and between .30 and .35. And then among those more recently
discovered, having diameters so small that measurement of them has not
been practicable, come the extremely erratic ones,--Hilda and Thule,
which have mean distances of 3.97 and 4.25 respectively; Æthra, having
an orbit so eccentric that it cuts the orbit of Mars; and Medusa, which
has the smallest mean distance from the Sun of any. (5) If the average
eccentricities of the orbits of the planetoids grouped according to
their decreasing sizes are compared, no very definite results are
disclosed, excepting this, that the eight Polyhymnia, Atalanta,
Eurydice, Æthra, Eva, Andromache, Istria, and Eudora, which have the
greatest eccentricities (falling between .30 and .38), are all among
those of smallest star-magnitudes. Nor when we consider the inclinations
of the orbits do we meet with obvious verifications; since the
proportion of highly-inclined orbits among the smaller planetoids does
not appear to be greater than among the others. But consideration shows
that there are two ways in which these last comparisons are vitiated.
One is that the inclinations are measured from the plane of the
ecliptic, instead of being measured from the plane of the orbit of the
hypothetical planet. The other, and more important one, is that the
search for planetoids has naturally been carried on in that
comparatively narrow zone within which most of their orbits fall; and
that, consequently, those having the most highly-inclined orbits are the
least likely to have been detected, especially if they are at the same
time among the smallest. Moreover, considering the general relation
between the inclination of planetoid orbits and their eccentricities, it
is probable that among the orbits of these undetected planetoids are
many of the most eccentric. But while recognizing the incompleteness of
the evidence, it seems to me that it goes far to justify the hypothesis
of Olbers, and is quite incongruous with that of Laplace. And as having
the same meanings let me not omit the remarkable fact concerning the
planetoids discovered by D'Arrest, that "if their orbits are figured
under the form of material rings, these rings will be found so
entangled, that it would be possible, by means of one among them taken
at hazard, to lift up all the rest,"--a fact incongruous with Laplace's
hypothesis, which implies an approximate concentricity, but quite
congruous with the hypothesis of an exploded planet.

Next to be considered come phenomena, the bearings of which on the
question before us are scarcely considered--I mean those presented by
meteors and shooting stars. The natures and distributions of these
harmonize with the hypothesis of an exploded planet, and I think with no
other hypothesis. The theory of volcanic origin, joined with the remark
that the Sun emits jets which might propel them with adequate
velocities, seems quite untenable. Such meteoric bodies as have
descended to us, forbid absolutely the supposition of solar origin. Nor
can they rationally be ascribed to planetary volcanoes. Even were their
mineral characters appropriate, which many of them are not (for
volcanoes do not eject iron), no planetary volcanoes could propel them
with anything like the implied velocity--could no more withstand the
tremendous force to be assumed, than could a card-board gun the force
behind a rifle bullet. But that their mineral characters, various as
they are, harmonize with the supposition that they were derived from
the crust of a planet is manifest; and that the bursting of a planet
might give to them, and to shooting stars, the needful velocities, is a
reasonable conclusion. Along with those larger fragments of the crust
constituting the known planetoids, varying from some 200 miles in
diameter to little over a dozen, there would be sent out still more
multitudinous portions of the crust, decreasing in size as they
increased in number. And while there would thus result such masses as
occasionally fall through the Earth's atmosphere to its surface, there
would, in an accompanying process, be an adequate cause for the myriads
of far smaller masses which, as shooting stars, are dissipated in
passing through the Earth's atmosphere. Let us figure to ourselves, as
well as we may, the process of explosion.

Assume that the diameter of the missing planet was 20,000 miles; that
its solid crust was a thousand miles thick; that under this came a shell
of molten metallic matter which was another thousand miles thick; and
that the space, 16,000 miles in diameter, within this, was occupied by
the equally dense mass of gases above the "critical point", which,
entering into a proto-chemical combination, caused the destroying
explosion. The primary fissures in the crust must have been far
apart--probably averaging distances between them as great as the
thickness of the crust. Supposing them approximately equidistant, there
would, in the equatorial periphery, be between 60 and 70 fissures. By
the time the primary fragments thus separated had been heaved a mile
outwards, the fissures formed would severally have, at the surface, a
width of 170 odd yards. Of course these great masses, as soon as they
moved, would themselves begin to fall in pieces; especially at their
bounding surfaces. But passing over the resulting complications, we see
that when the masses had been propelled 10 miles outwards, the fissures
between them would be each a mile wide. Notwithstanding the enormous
forces at work, an appreciable interval would elapse before these vast
portions of the crust could be put in motion with any considerable
velocities. Perhaps the estimate will be under the mark if we assume
that it took 10 seconds to propel them through the first mile, and that,
by implication, at the end of 20 seconds they had travelled 4 miles, and
at the end of 30 seconds 9 miles. Supposing this granted, let us ask
what would be taking place in each intervening fissure a thousand miles
deep, which, in the space of half a minute, had opened out to nearly a
mile wide, and in the subsequent half minute to a chasm approaching 3
miles in width. There would first be propelled through it enormous jets
of the molten metals composing the internal liquid shell; and these
would part into relatively small masses as they were shot into space.
Presently, as the chasm opened to some miles in width, the molten metals
would begin to be followed by the equally dense gaseous matter behind,
and the two would rush out together. Soon the gases, predominating,
would carry with them the portions of the liquid shell continually
collapsing; until the blast became one filled with millions of small
masses, billions of smaller masses, and trillions of drops. These would
be driven into space in a stream, the emission of which would continue
for many seconds or even several minutes. Remembering the rate of motion
of the jets emitted from the solar surface, and supposing that the
blasts produced by this explosion reached only one-tenth of that rate,
these myriads of small masses and drops would be propelled with
planetary velocities, and in approximately the same direction. I say
approximately, because they would be made to deviate somewhat by the
friction and irregularities of the chasm passed through, and also by the
rotation of the planet. Observe, however, that though they would all
have immense velocities, their velocities would not be equal. During its
earlier stages the blast would be considerably retarded by the
resistance which the sides of its channel offered. When this became
relatively small the velocity of the blast would reach its maximum; from
which it would decline when the space for emission became very wide,
and the pressure behind consequently less. Hence these almost infinitely
numerous particles of planet-spray, as we might call it, as well as
those formed by the condensation of the metallic vapours accompanying
them, would forthwith begin to part company: some going rapidly in
advance, and others falling behind; until the stream of them,
perpetually elongating, formed an orbit round the Sun, or rather an
assemblage of innumerable orbits, separating widely at aphelion and
perihelion, but approximating midway, where they might fall within a
space of, say, some two millions of miles, as do the orbits of the
November meteors. At a later stage of the explosion, when the large
masses, having moved far outwards, had also fallen to pieces of every
size, from that of Vesta to that of an aerolite, and when the channels
just described had ceased to exist, the contents of the planet would
disperse themselves with lower velocities and without any unity of
direction. Hence we see causes alike for the streams of shooting stars,
for the solitary shooting stars visible to the naked eye, and for the
telescopic shooting stars a score times more numerous.

Further significant evidence is furnished by the comets of short
periods. Of the thirteen constituting this group, twelve have orbits
falling between those of Mars and Jupiter: one only having its aphelion
beyond the orbit of Jupiter. That is to say, nearly all of them frequent
the same region as the planetoids. By implication, they are similarly
associated in respect of their periods. The periods of the planetoids
range from 3.1 to 8.8 years; and all these twelve comets have periods
falling between these extremes: the least being 3.29 and the greatest
8.86. Once more this family of comets, like the planetoids in the zone
they occupy and like them in their periods, are like them also in the
respect that, as Mr. Lynn has pointed out, their motions are all direct.
How happens this close kinship--how happens there to be this family of
comets so much like the planetoids and so much like one another, but so
unlike comets at large? The obvious suggestion is that they are among
the products of the explosion which originated the planetoids, the
aerolites, and the streams of meteors; and consideration of the probable
circumstances shows us that such products might be expected. If the
hypothetical planet was like its neighbour Jupiter in having an
atmosphere, or like its neighbour Mars in having water on its surface,
or like both in these respects; then these superficial masses of liquid,
of vapour, and of gas, blown into space along with the solid matters,
would yield the materials for comets. There would result, too, comets
unlike one another in constitution. If a fissure opened beneath one of
the seas, the molten metals and metallic gases rushing through it as
above described, would decompose part of the water carried with them;
and the oxygen and hydrogen liberated would be mingled with undecomposed
vapour. In other cases, portions of the atmosphere might be propelled,
probably with portions of vapour; and in yet other cases masses of water
alone. Severally subject to great heat at perihelion, these would behave
more or less differently. Once more, it would ordinarily happen that
detached swarms of meteors projected as implied, would carry with them
masses of vapours and gases; whence would result the cometic
constitution now insisted on. And sometimes there would be like
accompaniments to meteoric streams.

See, then, the contrast between the two hypotheses. That of Laplace,
looking probable while there were only four planetoids, but decreasing
in apparent likelihood as the planetoids increase in number, until, as
they pass through the hundreds on their way to the thousands, it becomes
obviously improbable, is, at the same time, otherwise objectionable. It
pre-supposes a nebulous ring of a width so enormous that it would have
overlapped the ring of Mars. This ring would have had differences
between the angular velocities of its parts quite inconsistent with the
Nebular Hypothesis. The average eccentricities of the orbits of its
parts must have differed greatly from those of adjacent orbits; and the
average inclinations of the orbits of its parts must similarly have
differed greatly from those of adjacent orbits. Once more, the orbits of
its parts, confusedly interspersed, must have had varieties of
eccentricity and inclination unaccountable in portions of the same
nebulous ring; and, during concentration into planetoids, each must have
had to maintain its course while struggling through the assemblage of
other small nebulous masses, severally moving in ways unlike its own. On
the other hand, the hypothesis of an exploded planet is supported by
every increase in the number of planetoids discovered; by the greater
numbers of the smaller sizes; by the thicker clustering near the
inferred place of the missing planet; by the occurrence of the greatest
mean distances among the smallest members of the assemblage; by the
occurrence of the greatest eccentricities in the orbits of these
smallest members; and by the entanglement of all the orbits. Further
support for the hypothesis is yielded by aerolites, so various in their
kinds, but all suggestive of a planet's crust; by the streams of
shooting stars having their radiant points variously placed in the
heavens; and also by the solitary shooting stars visible to the naked
eye, and the more numerous ones visible through telescopes. Once more,
it harmonizes with the discovery of a family of comets, twelve out of
thirteen of which have mean distances falling within the zone of the
planetoids, have similarly associated periods, have all the same direct
motions, and are connected with swarms of meteors and with meteoric
streams. May we not, indeed, say, that if there once existed a planet
between Mars and Jupiter which burst, the explosion must have produced
just such clusters of bodies and classes of phenomena as we actually
find?

And what is the objection? Merely that if such an explosion occurred it
must have occurred many millions of years ago--an objection which is in
fact no objection; for the supposition that the explosion occurred many
millions of years ago is just as reasonable as the supposition that it
occurred recently.

It is, indeed, further objected that some of the resulting fragments
ought to have retrograde motions. It turns out on calculation, however,
that this is not the case. Assuming as true the velocity which Lagrange
estimated would have sufficed to give the four chief planetoids the
positions they occupy, it results that such a velocity, given to the
fragments which were propelled backwards by the explosion, would not
have given them retrograde motions, but would simply have reduced their
direct motions from something over 11 miles per second to about 6 miles
per second. It is, however, manifest that this reduction of velocity
would have necessitated the formation of highly-elliptic orbits--more
elliptic than any of those at present known. This seems to me the most
serious difficulty which has presented itself. Still, considering that
there remain probably an immense number of planetoids to be discovered,
it is quite possible that among these there may be some having orbits
answering to the requirement.


NOTE V. Shortly before I commenced the revision of the foregoing essay,
friends on two occasions named to me some remarkable photographs of
nebulæ recently obtained by Mr. Isaac Roberts, and exhibited at the
Royal Astronomical Society: saying that they presented appearances such
as might have been sketched by Laplace in illustration of his
hypothesis. Mr. Roberts has been kind enough to send me copies of the
photographs in question and sundry others illustrative of stellar
evolution. Those representing the Great Nebulæ in Andromeda and Canum
Venaticorum as well as 81 Messier are at once impressive and
instructive--illustrating as they do the genesis of nebulous rings round
a central mass.

I may remark, however, that they seem to suggest the need for some
modification of the current conception; since they make it tolerably
clear that the process is a much less uniform one than is supposed. The
usual idea is that a vast rotating nebulous spheroid arises before there
are produced any of the planet-forming rings. But both of these
photographs apparently imply that, in some cases at any rate, the
portions of nebulous matter composing the rings take shape before they
reach the central mass. It looks as though these partially-formed annuli
must be prevented by their acquired motions from approaching even very
near to the still-irregular body they surround.

Be this as it may, however, and be the dimensions of the incipient
systems what they may (and it would seem to be a necessary implication
that they are vastly larger than our Solar System), the process remains
essentially the same. Practically demonstrated as this process now is,
we may say that the doctrine of nebular genesis passes from the region
of hypothesis into the region of established truth.

FOOTNOTES:

[Footnote 21: Of course there remains the question whether, before the
stage here recognized, there had already been produced a high
temperature by those collisions of celestial masses which reduced the
matter to a nebulous form. As suggested in _First Principles_ (§ 136 in
the edition of 1862, and § 182 in subsequent editions), there must,
after there have been effected all those minor dissolutions which follow
evolutions, remain to be effected the dissolutions of the great bodies
in and on which the minor evolutions and dissolutions have taken place;
and it was argued that such dissolutions will be, at some time or other,
effected by those immense transformations of molar motion into molecular
motion, consequent on collisions: the argument being based on the
statement of Sir John Herschel, that in clusters of stars collisions
must inevitably occur. It may, however, be objected that though such a
result may be reasonably looked for in closely aggregated assemblages of
stars, it is difficult to conceive of its taking place throughout our
Sidereal System at large, the members of which, and their intervals, may
be roughly figured as pins-heads 50 miles apart. It would seem that
something like an eternity must elapse before, by ethereal resistance or
other cause, these can be brought into proximity great enough to make
collisions probable.]

[Footnote 22: The two sentences which, in the text, precede the
asterisk, I have introduced while these pages are standing in type:
being led to do so by the perusal of some notes kindly lent to me by
Prof. Dewar, containing the outline of a lecture he gave at the Royal
Institution during the session of 1880. Discussing the conditions under
which, if "our so-called elements are compounded of elemental matter",
they may have been formed, Prof. Dewar, arguing from the known habitudes
of compound substances, concludes that the formation is in each case a
function of pressure, temperature, and nature of the environing gases.]

[Footnote 23: At the date of this passage the established teleology made
it seem needful to assume that all the planets are habitable, and that
even beneath the photosphere of the Sun there exists a dark body which
may be the scene of life; but since then, the influence of teleology has
so far diminished that this hypothesis can no longer be called the
current one.]

[Footnote 24: It may here be mentioned (though the principal
significance of this comes under the next head) that the average mean
distance of the later-discovered planetoids is somewhat greater than
that of these earlier-discovered; amounting to 2·61 for Nos. 1 to 35 and
2·80 for Nos. 211 to 245. For this observation I am indebted to Mr.
Lynn; whose attention was drawn to it while revising for me the
statements contained in this paragraph, so as to include discoveries
made since the paragraph was written.]




THE CONSTITUTION OF THE SUN.

    [_First published in_ The Reader _for February_ 25, 1865. _I
    reproduce this essay chiefly to give a place to the speculation
    concerning the solar spots which forms the latter portion of it._]


The hypothesis of M. Faye, described in your numbers for January 28 and
February 4, respectively, is to a considerable extent coincident with
one which I ventured to suggest in an article on "Recent Astronomy and
the Nebular Hypothesis," published in the _Westminster Review_ for July,
1858. In considering the possible causes of the immense differences of
specific gravity among the planets, I was led to question the validity
of the tacit assumption that each planet consists of solid or liquid
matter from centre to surface. It seemed to me that any other internal
structure which was mechanically stable, might be assumed with equal
legitimacy. And the hypothesis of a solid or liquid shell, having its
cavity filled with gaseous matter at high pressure and temperature [and
of great density], was one which seemed worth considering.

Hence arose the inquiry--What structure will result from the process of
nebular condensation? [Here followed a long speculation respecting the
processes going on in a concentrating nebulous spheroid; the general
outcome of which is implied in Note III of the foregoing essay. I do not
reproduce it because, not having the guidance of Prof. Andrew's
researches, I had concluded that the formation of a molten shell would
occur universally, instead of occasionally, as is now argued in the
note named. The essay then proceeded thus:--]

The process of condensation being in its essentials the same for all
concentrating nebular spheroids, planetary or solar, it was argued that
the Sun is still passing through that incandescent stage which all the
planets have long ago passed through: his later aggregation, joined with
the immensely greater ratio of his mass to his surface, involving
comparative lateness of cooling. Supposing the sun to have reached the
state of a molten shell, inclosing a gaseous nucleus, it was concluded
that this molten shell, ever radiating its heat, but ever acquiring
fresh heat by further integration of the Sun's mass, must be constantly
kept up to that temperature at which its substance evaporates.

[Here followed part of the paragraph quoted in the preceding essay on p.
155; and there succeeded, in subsequent editions, a paragraph aiming to
show that the inferred structure of the Sun's interior was congruous
with the low specific gravity of the Sun--a conclusion which, as
indicated on p. 156, implies some very problematical assumptions
respecting the natures of the unknown elements of the Sun. There then
came this passage:--]

The conception of the Sun's constitution thus set forth, is like that of
M. Faye in so far as the successive changes, the resulting structures,
and the ultimate state, are concerned; but unlike it in so far as the
Sun is supposed to have reached a later stage of concentration. As I
gather from your abstract of M. Faye's paper [this referred to an
article in _The Reader_], he considers the Sun to be at present a
gaseous spheroid, having an envelope of metallic matters precipitated in
the shape of luminous clouds, the local dispersions of which, caused by
currents from within, appear to us as spots; and he looks forward to the
future formation of a liquid film as an event that will soon be followed
by extinction. Whereas the above hypothesis is that the liquid film
already exists beneath the visible photosphere, and that extinction
cannot result until, in the course of further aggregation, the gaseous
nucleus has become so much reduced, and the shell so much thickened,
that the escape of the heat generated is greatly retarded.... M. Faye's
hypothesis appears to be espoused by him, partly because it affords an
explanation of the spots, which are considered as openings in the
photosphere, exposing the comparatively non-luminous gases filling the
interior. But if these interior gases are non-luminous from the absence
of precipitated matter, must they not for the same reason be
transparent? And if transparent, will not the light from the remote side
of the photosphere seen through them, be nearly as bright as that of the
side next to us? By as much as the intensely-heated gases of the
interior are disabled by the dissociation of their molecules from giving
off luminiferous undulations, by so much must they be disabled from
absorbing the light transmitted through them. And if their great
light-transmitting power is exactly complementary to their small
light-emitting power, there seems no reason why the interior of the Sun,
disclosed to us by openings in the photosphere, should not appear as
bright as its exterior.

Take, on the other hand, the supposition that a more advanced state of
concentration has been reached. A shell of molten metallic matter
enclosing a gaseous nucleus still higher in temperature than itself,
will be continually kept at the highest temperature consistent with its
state of liquid aggregation. Unless we assume that simple radiation
suffices to give off all the heat generated by progressing integration,
we must conclude that the mass will be raised to that temperature at
which part of its heat is absorbed in vaporizing its superficial parts.
The atmosphere of metallic gases hence resulting, cannot continue to
accumulate without reaching a height above the Sun's surface, at which
the cooling due to radiation and rarefaction will cause condensation
into cloud--cannot, indeed, cease accumulating until the precipitation
from the upper limit of the atmosphere balances the evaporation from its
lower limit. This upper limit of the atmosphere of metallic gases,
whence precipitation is perpetually taking place, will form the visible
photosphere--partly giving off light of its own, partly letting through
the more brilliant light of the incandescent mass below. This conclusion
harmonizes with the appearances. Sir John Herschel, advocating though he
does an antagonist hypothesis, gives a description of the Sun's surface
which agrees completely with the processes here supposed. He says:--

     "There is nothing which represents so faithfully this appearance as
     the slow subsidence of some flocculent chemical precipitates in a
     transparent fluid, when viewed perpendicularly from above: so
     faithfully, indeed, that it is hardly possible not to be impressed
     with the idea of a luminous medium intermixed, but not confounded,
     with a transparent and non-luminous atmosphere, either floating as
     clouds in our air, or pervading it in vast sheets and columns like
     flame, or the streamers of our northern lights".--_Treatise on
     Astronomy_, p. 208.

If the constitution of the Sun be that which is above inferred, it does
not seem difficult to conceive still more specifically the production of
these appearances. Everywhere throughout the atmosphere of metallic
vapours which clothes the solar surface, there must be ascending and
descending currents. The magnitude of these currents must obviously
depend on the depth of this atmosphere. If it is shallow, the currents
must be small; but if many thousands of miles deep, the currents may be
wide enough to render visible to us the places at which they severally
impinge on the limit of the atmosphere, and the places whence the
descending currents commence. The top of an ascending current will be a
space over which the thickness of condensed cloud is the least, and
through which the greatest amount of light from beneath penetrates. The
clouds perpetually formed at the top of such a current, will be
perpetually thrust aside by the uncondensed gases from below them; and,
growing while they are thrust aside, will collect in the spaces between
the ascending currents, where there will result the greatest degree of
opacity. Hence the mottled appearance--hence the "pores," or dark
interspaces, separating the light-giving spots.[25]

Of the more special appearances which the photosphere presents, let us
take first the faculæ. These are ascribed to waves in the photosphere;
and the way in which such waves might produce an excess of light has
been variously explained in conformity with various hypotheses. What
would result from them in a photosphere constituted and conditioned as
above supposed? Traversing a canopy of cloud, here thicker and there
thinner, a wave would cause a disturbance very unlikely to leave the
thin and thick parts without any change in their average permeability to
light. There would probably be, at some parts of the wave, extensions in
the areas of the light-transmitting clouds, resulting in the passage of
more rays from below. Another phenomenon, less common but more striking,
appears also to be in harmony with the hypothesis. I refer to those
bright spots, of a brilliancy greater than that of the photosphere,
which are sometimes observed. In the course of a physical process so
vast and so active as that here supposed to be going on in the Sun, we
may expect that concurrent causes will occasionally produce ascending
currents much hotter than usual, or more voluminous, or both. One of
these, on reaching the stratum of luminous and illuminated cloud forming
the photosphere, will burst through it, dispersing and dissolving it,
and ascending to a greater height before it begins itself to condense:
meanwhile allowing to be seen, through its transparent mass, the
incandescent molten shell of the sun's body.

[The foregoing passages, to most of which I do not commit myself as more
than possibilities, I republish chiefly as introductory to the following
speculation, which, since it was propounded in 1865, has met with some
acceptance.]

"But what of the spots commonly so called?" it will be asked. In the
essay on the Nebular hypothesis, above quoted from, it was suggested
that refraction of the light passing through the depressed centres of
cyclones in this atmosphere of metallic gases, might possibly be the
cause; but this, though defensible as a "true cause," appeared on
further consideration to be an inadequate cause. Keeping the question in
mind, however, and still taking as a postulate the conclusion of Sir
John Herschel, that the spots are in some way produced by cyclones, I
was led, in the course of the year following the publication of the
essay, to an hypothesis which seemed more satisfactory. This, which I
named at the time to Prof. Tyndall, had a point in common with the one
afterward published by Prof. Kirchhoff, in so far as it supposed cloud
to be the cause of darkness; but differed in so far as it assigned the
cause of such cloud. More pressing matters prevented me from developing
the idea for some time; and, afterwards, I was deterred from including
it in the revised edition of the essay, by its inconsistency with the
"willow-leaf" doctrine, at that time dominant. The reasoning was as
follows:--The central region of a cyclone must be a region of
rarefaction, and, consequently, a region of refrigeration. In an
atmosphere of metallic gases rising from a molten surface, and presently
reaching a limit at which condensation takes place, the molecular state,
especially toward its upper part, must be such that a moderate
diminution of density, and fall of temperature, will cause
precipitation. That is to say, the rarefied interior of a solar cyclone
will be filled with cloud: condensation, instead of taking place only
at the level of the photosphere, will here extend to a great depth below
it, and over a wide area. What will be the characters of a cloud thus
occupying the interior of a cyclone? It will have a rotatory motion; and
this it has been seen to have. Being funnel-shaped, as analogy warrants
us in assuming, its central parts will be much deeper than its
peripheral parts, and therefore more opaque. This, too, corresponds with
observation. Mr. Dawes has discovered that in the middle of the spot
there is a blacker spot: just where there would exist a funnel-shaped
prolongation of the cyclonic cloud down toward the Sun's body, the
darkness is greater than elsewhere. Moreover, there is furnished an
adequate reason for the depression which one of these dark spaces
exhibits. In a whirlwind, as in a whirlpool, the vortex will be below
the general level, and all around, the surface of the medium will
descend toward it. Hence a spot seen obliquely, as when carried toward
the Sun's limb, will have its umbra more and more hidden, while its
penumbra still remains visible. Nor are we without some interpretation
of the penumbra. If, as is implied by what has been said, the so-called
"willow-leaves," or "rice-grains," are the tops of the currents
ascending from the Sun's body, what changes of appearance are they
likely to undergo in the neighbourhood of a cyclone? For some distance
round a cyclone there will be a drawing in of the superficial gases
toward the vortex. All the luminous spaces of more transparent cloud
forming the adjacent photosphere, will be changed in shape by these
centripetal currents. They will be greatly elongated; and there will so
be produced that "thatch"-like aspect which the penumbra presents.

       *       *       *       *       *

[The explanation of the solar spots above suggested, which was
originally propounded in opposition to that of M. Faye, was eventually
adopted by him in place of his own. In the _Comptes Rendus_ for 1867,
Vol. LXIV., p. 404, he refers to the article in the _Reader_, partly
reproduced above, and speaks of me as having been replied to in a
previous note. Again in the _Comptes Rendus_ for 1872, Vol. LXXV., p.
1664, he recognizes the inadequacy of his hypothesis, saying:--"Il est
certain que l'objection de M. Spencer, reproduit et développée par M.
Kirchoff, est fondée jusqu'à un certain point; l'intérieur des taches,
si ce sont des lacunes dans la photosphère, doit être froid
relativement.... Il est donc impossible qu'elles proviennent d'éruptions
ascendantes." He then proceeds to set forth the hypothesis that the
spots are caused by the precipitation of vapour in the interiors of
cyclones. But though, as above shown, he refers to the objection made in
the foregoing essay to his original hypothesis, and recognizes its
cogency, he does not say that the hypothesis which he thereupon
substitutes is also to be found in the foregoing essay. Nor does he
intimate this in the elaborate paper on the subject read before the
French Association for the Advancement of Science, and published in the
_Revue Scientifique_ for the 24th March 1883. The result is that the
hypothesis is now currently ascribed to him.[26]

About four months before I had to revise this essay on "The Constitution
of the Sun," while staying near Pewsey, in Wiltshire, I was fortunate
enough to witness a phenomenon which furnished, by analogy, a
verification of the above hypothesis, and served more especially to
elucidate one of the traits of solar spots, otherwise difficult to
understand. It was at the close of August, when there had been a spell
of very hot weather. A slight current of air from the West, moving along
the line of the valley, had persisted through the day, which, up to 5
o'clock, had been cloudless, and, with the exception now to be named,
remained cloudless. The exception was furnished by a strange-looking
cloud almost directly overhead. Its central part was comparatively dense
and structureless. Its peripheral part, or to speak strictly, the
two-thirds of it which were nearest and most clearly visible, consisted
of _converging streaks_ of comparatively thin cloud. Possibly the third
part on the remoter side was similarly constituted; but this I could not
see. It did not occur to me at the time to think about its cause,
though, had the question been raised, I should doubtless have concluded
that as the sky still remained cloudless everywhere else, this
precipitated mass of vapour must have resulted from a local eddy. In the
space of perhaps half-an-hour, the gentle breeze had carried this cloud
some miles to the East; and now its nature became obvious. That central
part which, seen from underneath, seemed simply a dense, confused part,
apparently no nearer than the rest, now, seen sideways, was obviously
much lower than the rest and rudely funnel-shaped--nipple-shaped one
might say; while the wide thin portion of cloud above it was
disk-shaped: the converging streaks of cloud being now, in perspective,
merged together. It thus became manifest that the cloud was produced by
a feeble whirlwind, perhaps a quarter to half-a-mile in diameter.
Further, the appearances made it clear that this feeble whirlwind was
limited to the lower stratum of air: the stratum of air above it was not
implicated in the cyclonic action. And then, lastly, there was the
striking fact that the upper stratum, though not involved in the whirl,
was, by its proximity to a region of diminished pressure, slightly
rarified; and that its precipitated vapour was, by the draught set up
towards the vortex below, drawn into converging streaks. Here, then, was
an action analogous to that which, as above suggested, happens around a
sun-spot, where the masses of illuminated vapour constituting the
photosphere are drawn towards the vortex of the cyclone, and
simultaneously elongated into striæ: so forming the penumbra. At the
same time there was furnished an answer to the chief objection to the
cyclonic theory of solar spots. For if, as here seen, a cyclone in a
lower stratum may fail to communicate a vortical motion to the stratum
above it, we may comprehend how, in a solar cyclone, the photosphere
commonly fails to give any indication of the revolving currents below,
and is only occasionally so entangled in these currents as itself to
display a vortical motion.

Let me add that apart from the elucidations furnished by the phenomenon
above described, the probabilities are greatly in favour of the cyclonic
origin of the solar spots. That some of them exhibit clear marks of
vortical motion is undeniable; and if this is so, the question
arises--What is the degree of likelihood that there are two causes for
spots? Considering that they have so many characters in common, it is
extremely improbable that their common characters are in some cases the
concomitants of vortical motion and in other cases the concomitants of a
different kind of action. Recognizing this great improbability, even in
the absence of a reconciliation between the apparently conflicting
traits, it is, I think, clear that when, in the way above shown, we are
enabled to understand how it happens that the vortical motion, not
ordinarily implicating the photosphere, may consequently be in most
cases unapparent, the reasons for accepting the cyclonic theory become
almost conclusive.]

FOOTNOTES:

[Footnote 25: If the "rice-grain" appearance is thus produced by the
tops of the ascending currents (and M. Faye accepts this
interpretation), then I think it excludes M. Faye's hypothesis that the
Sun is gaseous throughout. The comparative smallness of the light-giving
spots and their comparative uniformity of size, show us that they have
ascended through a stratum of but moderate depth (say 10,000 miles), and
that this stratum has a _definite_ lower limit. This favours the
hypothesis of a molten shell.]

[Footnote 26: I should add that while M. Faye ascribes solar spots to
clouds formed within cyclones, we differ concerning the nature of the
cloud. I have argued that it is formed by rarefaction, and consequent
refrigeration, of the metallic gases constituting the stratum in which
the cyclone exists. He argues that it is formed within the mass of
cooled hydrogen drawn from the chromosphere into the vortex of the
cyclone. Speaking of the cyclones he says:--"Dans leur embouchure évasée
ils entraîneront l'hydrogène froid de la chromosphère, produisant
partout sur leur trajet vertical un abaissement notable de température
et une obscurité relative, due à l'opacité de l'hydrogène froid
englouti." (_Revue Scientifique_, 24 March 1883.) Considering the
intense cold required to reduce hydrogen to the "critical point," it is
a strong supposition that the motion given to it by fluid friction on
entering the vortex of the cyclone, can produce a rotation, rarefaction,
and cooling, great enough to produce precipitation in a region so
intensely heated.]




ILLOGICAL GEOLOGY.

    [_First published in_ The Universal Review _for July,_ 1859.]


That proclivity to generalization which is possessed in greater or less
degree by all minds, and without which, indeed, intelligence cannot
exist, has unavoidable inconveniences. Through it alone can truth be
reached; and yet it almost inevitably betrays into error. But for the
tendency to predicate of every other case, that which has been found in
the observed cases, there could be no rational thinking; and yet by this
indispensable tendency, men are perpetually led to found, on limited
experience, propositions which they wrongly assume to be universal or
absolute. In one sense, however, this can scarcely be regarded as an
evil; for without premature generalizations the true generalization
would never be arrived at. If we waited till all the facts were
accumulated before trying to formulate them, the vast unorganized mass
would be unmanageable. Only by provisional grouping can they be brought
into such order as to be dealt with; and this provisional grouping is
but another name for premature generalization. How uniformly men follow
this course, and how needful the errors are as steps to truth, is well
illustrated in the history of Astronomy. The heavenly bodies move round
the Earth in circles, said the earliest observers: led partly by the
appearances, and partly by their experiences of central motions in
terrestrial objects, with which, as all circular, they classed the
celestial motions from lack of any alternative conception. Without this
provisional belief, wrong as it was, there could not have been that
comparison of positions which showed that the motions are not
representable by circles; and which led to the hypothesis of epicycles
and eccentrics. Only by the aid of this hypothesis, equally untrue, but
capable of accounting more nearly for the appearances, and so of
inducing more accurate observations--only thus did it become possible
for Copernicus to show that the heliocentric theory is more feasible
than the geocentric theory; or for Kepler to show that the planets move
round the sun in ellipses. Yet again, without the aid of Kepler's more
advanced theory of the Solar system, Newton could not have established
that general law from which it follows, that the motion of a heavenly
body is not necessarily in an ellipse, but may be in any conic section.
And lastly, it was only after the law of gravitation had been verified,
that it became possible to determine the actual courses of planets,
satellites, and comets; and to prove that, in consequence of
perturbations, their orbits always deviate, more or less, from regular
curves. In these successive theories we may trace both the tendency men
have to leap from scanty data to wide generalizations, that are either
untrue or but partially true; and the necessity there is for such
transitional generalizations as steps to the final one.

In the progress of geological speculation, the same laws of thought are
displayed. We have dogmas that were more than half false, passing
current for a time as universal truths. We have evidence collected in
proof of these dogmas; by and by a colligation of facts in antagonism
with them; and eventually a consequent modification. In conformity with
this improved hypothesis, we have a better classification of facts; a
greater power of arranging and interpreting the new facts now rapidly
gathered together; and further resulting corrections of hypothesis.
Being, as we are at present, in the midst of this process, it is not
possible to give an adequate account of the development of geological
science as thus regarded: the earlier stages are alone known to us. Not
only, however, is it interesting to observe how the more advanced views
now received respecting the Earth's history, have been evolved out of
the crude views which preceded them; but we shall find it extremely
instructive to observe this. We shall see how greatly the old ideas
still sway both the general mind and the minds of geologists themselves.
We shall see how the kind of evidence that has in part abolished these
old ideas, is still daily accumulating, and threatens to make other like
revolutions. In brief, we shall see whereabouts we are in the
elaboration of a true theory of the Earth; and, seeing our whereabouts,
shall be the better able to judge, among various conflicting opinions,
which best conform to the ascertained direction of geological discovery.

It is needless here to enumerate the many speculations which were in
earlier ages propounded by acute men--speculations some of which
contained portions of truth. Falling in unfit times, these speculations
did not germinate; and hence do not concern us. We have nothing to do
with ideas, however good, out of which no science grew; but only with
those which gave origin to the existing system of Geology. We therefore
begin with Werner.

Taking for data the appearances of the Earth's crust in a narrow
district of Germany; observing the constant order of superposition of
strata, and their respective physical characters; Werner drew the
inference that strata of like characters succeeded each other in like
order over the entire surface of the Earth. And seeing, from the
laminated structure of many formations and the organic remains contained
in others, that they were sedimentary; he further inferred that these
universal strata had been in succession precipitated from a chaotic
menstruum which once covered our planet. Thus, on a very incomplete
acquaintance with a thousandth part of the Earth's crust, he based a
sweeping generalization applying to the whole of it. This Neptunist
hypothesis, mark, borne out though it seemed to be by the most
conspicuous surrounding facts, was quite untenable if analyzed. That a
universal chaotic menstruum should deposit a series of numerous
sharply-defined strata, differing from one another in composition, is
incomprehensible. That the strata so deposited should contain the
remains of plants and animals, which could not have lived under the
supposed conditions, is still more incomprehensible. Physically absurd,
however, as was this hypothesis, it recognized, though under a distorted
form, one of the great agencies of geological change--the action of
water. It served also to express the fact, that the formations of the
Earth's crust stand in some kind of order. Further, it did a little
towards supplying a nomenclature, without which much progress was
impossible. Lastly, it furnished a standard with which successions of
strata in various regions could be compared, the differences noted, and
the actual sections tabulated. It was the first provisional
generalization; and was useful, if not indispensable, as a step to truer
ones.

Following this rude conception, which ascribed geological phenomena to
one agency, acting during one primeval epoch, there came a
greatly-improved conception, which ascribed them to two agencies, acting
alternately during successive epochs. Hutton, perceiving that
sedimentary deposits were still being formed at the bottom of the sea
from the detritus carried down by rivers; perceiving, further, that the
strata of which the visible surface chiefly consists, bore marks of
having been similarly formed out of pre-existing land; and inferring
that these strata could have become land only by upheaval after their
deposit; concluded that throughout an indefinite past, there had been
periodic convulsions, by which continents were raised, with intervening
eras of repose, during which such continents were worn down and
transformed into new marine strata, fated to be in their turns elevated
above the surface of the ocean. And finding that igneous action, to
which sundry earlier geologists had ascribed basaltic rocks, was in
countless places a cause of disturbance, he taught that from it resulted
these periodic convulsions. In this theory we see:--first, that the
previously-recognized agency of water was conceived to act, not as by
Werner, after a manner of which we have no experience, but after a
manner daily displayed to us; and secondly, that the igneous agency,
before considered only as originating special formations, was recognized
as a universal agency, but assumed to act in an unproved way. Werner's
sole process Hutton developed from the catastrophic and inexplicable
into the uniform and explicable; while that antagonistic second process,
of which he first adequately estimated the importance, was regarded by
him as a catastrophic one, and was not assimilated to known
processes--not explained. We have here to note, however, that the facts
collected and provisionally arranged in conformity with Werner's theory,
served, after a time, to establish Hutton's more rational theory--in so
far, at least, as aqueous formations are concerned; while the doctrine
of periodic subterranean convulsions, crudely as it was conceived by
Hutton, was a temporary generalization needful as a step towards the
theory of igneous action.

Since Hutton's time, the development of geological thought has gone
still further in the same direction. These early sweeping doctrines have
received additional qualifications. It has been discovered that more
numerous and more heterogeneous agencies have been at work, than was at
first believed. The conception of igneous action has been rationalized,
as the conception of aqueous action had previously been. The gratuitous
assumption that vast elevations suddenly occurred after long intervals
of quiescence, has grown into the consistent theory, that islands and
continents are the accumulated results of successive small upheavals,
like those experienced in ordinary earthquakes. To speak more
specifically, we find, in the first place, that instead of assuming the
denudation produced by rain and rivers to be the sole means of wearing
down lands and producing their irregularities of surface, geologists now
see that denudation is only a part-cause of such irregularities; and
further, that the new strata deposited at the bottom of the sea, are not
the products of river-sediment solely, but are in part due to the
actions of waves and tidal currents on the coasts. In the second place,
we find that Hutton's conception of upheaval by subterranean forces, has
not only been modified by assimilating these subterranean forces to
ordinary earthquake-forces; but modern inquiries have shown that,
besides elevations of surface, subsidences are thus produced; that local
upheavals, as well as the general upheavals which raise continents, come
within the same category; and that all these changes are probably
consequent on the progressive collapse of the Earth's crust upon its
cooling and contracting nucleus. In the third place, we find that beyond
these two great antagonistic agencies, modern Geology recognizes sundry
minor ones: those of glaciers and icebergs, those of coral-polypes;
those of _Protozoa_ having siliceous or calcareous shells--each of which
agencies, insignificant as it seems, is found capable of slowly working
terrestrial changes of considerable magnitude. Thus, then, the recent
progress of Geology has been a still further departure from primitive
conceptions. Instead of one catastrophic cause, once in universal
action, as supposed by Werner--instead of one general continuous cause,
antagonized at long intervals by a catastrophic cause, as taught by
Hutton; we now recognize several causes, all more or less general and
continuous. We no longer resort to hypothetical agencies to explain the
phenomena displayed by the Earth's crust; but we are day by day more
clearly perceiving that these phenomena have arisen from forces like
those now at work, which have acted in all varieties of combination,
through immeasurable periods of time.

       *       *       *       *       *

Having thus briefly traced the evolution of geologic science, and noted
its present form, let us go on to observe the way in which it is still
swayed by the crude hypotheses it set out with; so that even now,
doctrines long since abandoned as untenable in theory, continue in
practice to mould the ideas of geologists, and to foster sundry beliefs
that are logically indefensible. We shall see, both how those simple
sweeping conceptions with which the science commenced, are those which
every student is apt at first to seize hold of, and how several
influences conspire to maintain the twist thus resulting--how the
original nomenclature of periods and formations necessarily keeps alive
the original implications; and how the need for arranging new data in
some order, results in their being thrust into the old classification,
unless their incongruity with it is very glaring. A few facts will best
prepare the way for criticism.

Up to 1839 it was inferred, from their crystalline character, that the
metamorphic rocks of Anglesea were more ancient than any rocks of the
adjacent main land; but it has since been shown that they are of the
same age with the slates and grits of Carnarvon and Merioneth. Again,
slaty cleavage having been first found only in the lowest rocks, was
taken as an indication of the highest antiquity: whence resulted serious
mistakes; for this mineral characteristic is now known to occur in the
Carboniferous system. Once more, certain red conglomerates and grits on
the north-west coast of Scotland, long supposed from their lithological
aspect to belong to the Old Red Sandstone, are now identified with the
Lower Silurians. These are a few instances of the small trust to be
placed in mineral qualities, as evidence of the ages or relative
positions of strata. From the recently-published third edition of
_Siluria_, may be culled numerous facts of like implication. Sir R.
Murchison considers it ascertained, that the siliceous Stiper stones of
Shropshire are the equivalents of the Tremadock slates of North Wales.
Judged by their fossils, Bala slate and limestone are of the same age as
the Caradoc sandstone, lying forty miles off. In Radnorshire, the
formation classed as upper Llandovery rock, is described at different
spots, as "sandstone or conglomerate," "impure limestone," "hard coarse
grits," "siliceous grit"--a considerable variation for so small an area
as that of a county. Certain sandy beds on the left bank of the Towy,
which Sir R. Murchison had, in his _Silurian System_, classed as Caradoc
sandstone (evidently from their mineral characters), he now finds, from
their fossils, belong to the Llandeilo formation. Nevertheless,
inferences from mineral characters are still habitually drawn and
received. Though _Siluria_, in common with other geological works,
supplies numerous proofs that rocks of the same age are often of
widely-different composition a few miles off, while rocks of
widely-different ages are often of similar composition; and though Sir
R. Murchison shows us, as in the case just cited, that he has himself in
past times been misled by trusting to lithological evidence; yet his
reasoning all through _Siluria_, shows that he still thinks it natural
to expect formations of the same age to be chemically similar, even in
remote regions. For example, in treating of the Silurian rocks of South
Scotland, he says:--"When traversing the tract between Dumfries and
Moffat, in 1850, it occurred to me, that the dull reddish or purple
sandstone and schist to the north of the former town, which so resembled
the bottom rocks of Longmynd, Llanberis, and St. David's, would prove to
be of the same age;" and further on, he again insists upon the fact that
these strata "are absolutely of the same composition as the bottom rocks
of the Silurian region." On this unity of mineral character it is, that
this Scottish formation is concluded to be contemporaneous with the
lowest formations in Wales; for the scanty paleontological evidence
suffices for neither proof nor disproof. Now, had there been a
continuity of like strata in like order between Wales and Scotland,
there might have been little to criticize in this conclusion. But since
Sir R. Murchison himself admits, that in Westmoreland and Cumberland,
some members of the system "assume a lithological aspect different from
what they maintain in the Silurian and Welsh region," there seems no
reason to expect mineralogical continuity in Scotland. Obviously,
therefore, the assumption that these Scottish formations are of the same
age with the Longmynd of Shropshire, implies the latent belief that
certain mineral characters indicate certain eras. Far more striking
instances, however, of the influence of this latent belief remain to be
given. Not in such comparatively near districts as the Scottish lowlands
only, does Sir R. Murchison expect a repetition of the Longmynd strata;
but in the Rhenish provinces, certain "quartzose flagstones and grits,
like those of the Longmynd," are seemingly concluded to be of
contemporaneous origin, because of their likeness. "Quartzites in
roofing-slates with a greenish tinge that reminded us of the lower
slates of Cumberland and Westmoreland," are evidently suspected to be of
the same age. In Russia, he remarks that the carboniferous limestones
"are overlaid along the western edge of the Ural chain by sandstones and
grits, which occupy much the same place in the general series as the
millstone grit of England;" and in calling this group, as he does, the
"representative of the millstone grit," Sir R. Murchison clearly shows
that he thinks likeness of mineral composition some evidence of
equivalence in time, even at that great distance. Nay, on the flanks of
the Andes and in the United States, such similarities are looked for,
and considered as significant of certain ages. Not that Sir R. Murchison
contends theoretically for this relation between lithological character
and date. For on the page from which we have just quoted (_Siluria_,
p. 387), he says, that "whilst the soft Lower Silurian clays and sands
of St. Petersburg have their equivalents in the hard schists and quartz
rocks with gold veins in the heart of the Ural mountains, the equally
soft red and green Devonian marls of the Valdai Hills are represented on
the western flank of that chain by hard, contorted, and fractured
limestones." But these, and other such admissions, seem to go for
little. While himself asserting that the Potsdam-sandstone of North
America, the Lingula-flags of England, and the alum-slates of
Scandinavia are of the same period--while fully aware that among the
Silurian formations of Wales, there are oolitic strata like those of
secondary age; yet his reasoning is more or less coloured by the
assumption, that formations of like qualities probably belong to the
same era. Is it not manifest, then, that the exploded hypothesis of
Werner continues to influence geological speculation?

"But," it will perhaps be said, "though individual strata are not
continuous over large areas, yet systems of strata are. Though within a
few miles the same bed gradually passes from clay into sand, or thins
out and disappears, yet the group of strata to which it belongs does not
do so; but maintains in remote regions the same relations to other
groups."

This is the generally-current belief. On this assumption the received
geological classifications appear to be framed. The Silurian system, the
Devonian system, the Carboniferous system, etc., are set down in our
books as groups of formations which everywhere succeed each other in a
given order; and are severally everywhere of the same age. Though it may
not be asserted that these successive systems are universal; yet it
seems to be tacitly assumed that they are. In North and South America,
in Asia, in Australia, sets of strata are assimilated to one or other of
these groups; and their possession of certain mineral characters and a
certain order of superposition are among the reasons assigned for so
assimilating them. Though, probably, no competent geologist would
contend that the European classification of strata is applicable to the
globe as a whole; yet most, if not all geologists, write as though it
were. Among readers of works on Geology, nine out of ten carry away the
impression that the divisions, Primary, Secondary and Tertiary, are of
absolute and uniform application; that these great divisions are
separable into subdivisions, each of which is definitely distinguishable
from the rest, and is everywhere recognizable by its characters as such
or such; and that in all parts of the Earth, these minor systems
severally began and ended at the same time. When they meet with the term
"Carboniferous era," they take for granted that it was an era
universally carboniferous--that it was, what Hugh Miller indeed actually
describes it, an era when the Earth bore a vegetation far more luxuriant
than it has since done; and were they in any of our colonies to meet
with a coal-bed, they would conclude that, as a matter of course, it was
of the same age as the English coal-beds.

Now this belief that geologic "systems" are universal, is no more
tenable than the other. It is just as absurd when considered _a priori_;
and it is equally inconsistent with the facts. Though some series of
strata classed together as Oolite, may range over a wider district than
any one stratum of the series; yet we have but to ask what were the
circumstances under which it was deposited, to see that the Oolitic
series, like one of its individual strata, must be of local origin; and
that there is not likely to be anywhere else, a series which
corresponds, either in its characters or in its commencement and
termination. For the formation of such a series implies an area of
subsidence, in which its component beds were thrown down. Every area of
subsidence is necessarily limited; and to suppose that there exist
elsewhere groups of beds completely answering to those known as Oolite,
is to suppose that, in contemporaneous areas of subsidence, like
processes were going on. There is no reason to suppose this; but good
reason to suppose the reverse. That in contemporaneous areas of
subsidence throughout the globe, the conditions would cause the
formation of Oolite, is an assumption which no modern geologist would
openly make. He would say that the equivalent series of beds found
elsewhere, would probably be of dissimilar mineral character. Moreover,
in these contemporaneous areas of subsidence, the processes going on
would not only be different in kind; but in no two cases would they be
likely to agree in their commencements and terminations. The
probabilities are greatly against separate portions of the Earth's
surface beginning to subside at the same time, and ceasing to subside at
the same time--a coincidence which alone could produce equivalent groups
of strata. Subsidences in different places begin and end with utter
irregularity; and hence the groups of strata thrown down in them can but
rarely correspond. Measured against each other in time, their limits
must disagree. On turning to the evidence, we find that it daily tends
more and more to justify these _a priori_ positions. Take, as an
example, the Old Red Sandstone system. In the north of England this is
represented by a single stratum of conglomerate. In Herefordshire,
Worcestershire, and Shropshire, it expands into a series of strata from
eight to ten thousand feet thick, made up of conglomerates, red, green,
and white sandstones, red, green, and spotted marls, and concretionary
limestones. To the south-west, as between Caermarthen and Pembroke,
these Old Red Sandstone strata exhibit considerable lithological
changes; on the other side of the Bristol Channel, they display further
changes in mineral characters; while in South Devon and Cornwall, the
equivalent strata, consisting chiefly of slates, schists, and
limestones, are so wholly different, that they were for a long time
classed as Silurian. When we thus see that in certain directions the
whole group of deposits thins out, and that its mineral characters
change within moderate distances; does it not become clear that the
whole group of deposits was a local one? And when we find, in other
regions, formations analogous to these Old Red Sandstone or Devonian
formations, is it certain--is it even probable--that they severally
began and ended at the same time with them? Should it not require
overwhelming evidence to make us believe as much?

Yet so strongly is geological speculation swayed by the tendency to
regard the phenomena as general instead of local, that even those most
on their guard against it seem unable to escape its influence. At page
158 of his _Principles of Geology_, Sir Charles Lyell says:--

     "A group of red marl and red sandstone, containing salt and gypsum,
     being interposed in England between the Lias and the Coal, all
     other red marls and sandstones, associated some of them with salt,
     and others with gypsum, and occurring not only in different parts
     of Europe, but in North America, Peru, India, the salt deserts of
     Asia, those of Africa--in a word, in every quarter of the globe,
     were referred to one and the same period.... It was in vain to urge
     as an objection the improbability of the hypothesis which implies
     that all the moving waters on the globe were once simultaneously
     charged with sediment of a red colour. But the rashness of
     pretending to identify, in age, all the red sandstones and marls in
     question, has at length been sufficiently exposed, by the discovery
     that, even in Europe, they belong decidedly to many different
     epochs."

Nevertheless, while in this and many kindred passages Sir C. Lyell
protests against the bias here illustrated, he seems himself not
completely free from it. Though he utterly rejects the old hypothesis
that all over the Earth the same continuous strata lie one upon another
in regular order, like the coats of an onion, he still writes as though
geologic "systems" do thus succeed each other. A reader of his _Manual_
would certainly suppose him to believe, that the Primary epoch ended,
and the secondary epoch began, all over the world at the same time--that
these terms really correspond to distinct universal eras. When he
assumes, as he does, that the division between Cambrian and Lower
Silurian in America, answers chronologically to the division between
Cambrian and Lower Silurian in Wales--when he takes for granted that
the partings of Lower from Middle Silurian, and of Middle Silurian from
Upper, in the one region, are of the same dates as the like partings in
the other region; does it not seem that he believes geologic "systems"
to be universal, in the sense that their separations were in all places
contemporaneous? Though he would, doubtless, disown this as an article
of faith, is not his thinking unconsciously influenced by it? Must we
not say that, though the onion-coat hypothesis is dead, its spirit is
traceable, under a transcendental form, even in the conclusions of its
antagonists?

       *       *       *       *       *

Let us now consider another leading geological doctrine,--the doctrine
that strata of the same age contain like fossils; and that, therefore,
the age and relative position of any stratum may be known by its
fossils. While the theory that strata of like mineral characters were
everywhere deposited simultaneously, has been ostensibly abandoned,
there has been accepted the theory that in each geologic epoch similar
plants and animals existed everywhere; and that, therefore, the epoch to
which any formation belongs may be known by the organic remains
contained in the formation. Though, perhaps, no leading geologist would
openly commit himself to an unqualified assertion of this theory, yet it
is tacitly assumed in current geological reasoning.

This theory, however, is scarcely more tenable than the other. It cannot
be concluded with any certainty, that formations in which similar
organic remains are found, were of contemporaneous origin; nor can it be
safely concluded that strata containing different organic remains are of
different ages. To most readers these will be startling propositions;
but they are fully admitted by the highest authorities. Sir Charles
Lyell confesses that the test of organic remains must be used "under
very much the same restrictions as the test of mineral composition." Sir
Henry de la Beche, who variously illustrates this truth, remarks on the
great incongruity there must be between the fossils of our carboniferous
rocks and those of the marine strata deposited at the same period. But
though, in the abstract, the danger of basing positive conclusions on
evidence derived from fossils, is recognized; yet, in the concrete, this
danger is generally disregarded. The established convictions respecting
the ages of strata, have been formed in spite of it; and by some
geologists it seems altogether ignored. Throughout his _Siluria_, Sir R.
Murchison habitually assumes that the same, or kindred, species, lived
in all parts of the Earth at the same time. In Russia, in Bohemia, in
the United States, in South America, strata are classed as belonging to
this or that part of the Silurian system, because of the similar fossils
contained in them--are concluded to be everywhere contemporaneous if
they enclose a proportion of identical or allied forms. In Russia the
relative position of a stratum is inferred from the fact that, along
with some Wenlock forms, it yields the _Pentamerus oblongus_. Certain
crustaceans called _Eurypteri_, being characteristic of the Upper Ludlow
rock, it is remarked that "large Eurypteri occur in a so-called black
grey-wacke slate in Westmoreland, in Oneida County, New York, which will
probably be found to be on the parallel of the Upper Ludlow rock:" in
which word "probably," we see both how dominant is this belief of
universal distribution of similar creatures at the same period, and how
apt this belief is to make its own proof, by raising the expectation
that the ages are identical when the forms are alike. Besides thus
interpreting the formations of Russia, England, and America, Sir R.
Murchison thus interprets those of the antipodes. Fossils from Victoria
Colony, he agrees with the Government-surveyor in classing as of Lower
Silurian or Llandovery age: that is, he takes for granted that when
certain crustaceans and mollusks were living in Wales, certain similar
crustaceans and mollusks were living in Australia. Yet the
improbability of this assumption may be readily shown from Sir R.
Murchison's own facts. If, as he points out, the fossil crustaceans of
the uppermost Silurian rocks in Lanarkshire are, "with one doubtful
exception," all "distinct from any of the forms known on the same
horizon in England;" how can it be fairly presumed that the forms
existing on the other side of the Earth during the Silurian period, were
nearly allied to those existing here? Not only, indeed, do Sir R.
Murchison's conclusions tacitly assume this doctrine of universal
distribution, but he distinctly enunciates it. "The mere presence of a
graptolite," he says, "will at once decide that the enclosing rock is
Silurian;" and he says this, notwithstanding repeated warnings against
such generalizations. During the progress of Geology, it has over and
over again happened that a particular fossil, long considered
characteristic of a particular formation, has been afterwards discovered
in other formations. Until some twelve years ago, Goniatites had not
been found lower than the Devonian rocks; but now, in Bohemia, they have
been found in rocks classed as Silurian. Quite recently, the
_Orthoceras_, previously supposed to be a type exclusively palæozoic,
has been detected along with mesozoic Ammonites and Belemnites. Yet
hosts of such experiences fail to extinguish the assumption, that the
age of a stratum may be determined by the occurrence in it of a single
fossil form. Nay, this assumption survives evidence of even a still more
destructive kind. Referring to the Silurian system in Western Ireland,
Sir R. Murchison says, "in the beds near Maam, Professor Nicol and
myself collected remains, some of which would be considered Lower, and
others Upper, Silurian;" and he then names sundry fossils which, in
England, belong to the summit of the Ludlow rocks, or highest Silurian
strata; "some, which elsewhere are known only in rocks of Llandovery
age"--that is, of middle Silurian age; and some, only before known in
Lower Silurian strata, not far above the most ancient fossiliferous
beds. Now what do these facts prove? Clearly, they prove that species
which in Wales are separated by strata more than twenty thousand feet
deep, and therefore seem to belong to periods far more remote from each
other, were really co-existent. They prove that the mollusks and
crinoids held to be characteristic of early Silurian strata, and
supposed to have become extinct long before the mollusks and crinoids of
the later Silurian strata came into existence, were really flourishing
at the same time with these last; and that these last possibly date back
to as early a period as the first. They prove that not only the mineral
characters of sedimentary formations, but also the collections of
organic forms they contain, depend, to a great extent, on local
circumstances. They prove that the fossils met with in any series of
strata, cannot be taken as representing anything like the whole Flora
and Fauna of the period they belong to. In brief, they throw great doubt
upon numerous geological generalizations.

Notwithstanding facts like these, and notwithstanding his avowed opinion
that the test of organic remains must be used "under very much the same
restrictions as the test of mineral composition," Sir Charles Lyell,
too, considers sundry positive conclusions to be justified by this test:
even where the community of fossils is slight and the distance great.
Having decided that in various places in Europe, middle Eocene strata
are distinguished by Nummulites; he infers, without any other assigned
evidence, that wherever Nummulites are found--in Morocco, Algeria,
Egypt, in Persia, Scinde, Cutch, Eastern Bengal, and the frontiers of
China--the containing formation is Middle Eocene. And from this
inference he draws the following important corollary:--

     "When we have once arrived at the conviction that the nummulitic
     formation occupies a middle place in the Eocene series, we are
     struck with the comparatively modern date to which some of the
     greatest revolutions in the physical geography of Europe, Asia, and
     northern Africa must be referred. All the mountain chains, such as
     the Alps, Pyrenees, Carpathians, and Himalayas, into the
     composition of whose central and loftiest parts the nummulitic
     strata enter bodily, could have had no existence till after the
     Middle Eocene period."--_Manual_, p. 232.

A still more marked case follows on the next page. Because a certain bed
at Claiborne in Alabama, which contains "_four hundred_ species of
marine shells," includes among them the _Cardita planicosta_, "and _some
others_ identical with European species, or very nearly allied to them,"
Sir C. Lyell says it is "highly probable the Claiborne beds agree in age
with the central or Bracklesham group of England." When we find
contemporaneity alleged on the strength of a community no greater than
that which sometimes exists between strata of widely-different ages in
the same country, it seems as though the above-quoted caution had been
forgotten. It appears to be assumed for the occasion, that species which
had a wide range in space had a narrow range in time; which is the
reverse of the fact. The tendency to systematize overrides the evidence,
and thrusts Nature into a formula too rigid to fit her endless variety.

"But," it may be urged, "surely, when in different places the order of
superposition, the mineral characters, and the fossils, agree, it may
safely be concluded that the formations thus corresponding date back to
the same time. If, for example, the United States display a succession
of Silurian, Devonian, and Carboniferous systems, lithologically similar
to those known here by those names, and characterized by like fossils,
it is a fair inference that these groups of strata were severally being
deposited in America while their equivalents were being deposited here."

On this position, which seems a strong one, we have, in the first place,
to remark, that the evidence of correspondence is always more or less
suspicious. We have already adverted to the several "idols"--if we may
use Bacon's metaphor--to which geologists unconsciously sacrifice, when
interpreting the structures of unexplored regions. Carrying with them
the classification of strata existing in Europe, and assuming that
groups of strata in other parts of the world must answer to some of the
groups of strata known here, they are necessarily prone to assert
parallelism on insufficient evidence. They scarcely entertain the
previous question, whether the formations they are examining have or
have not any European equivalents; but the question is--with which of
the European series shall they be classed?--with which do they most
agree?--from which do they differ least? And this being the mode of
inquiry, there is apt to result great laxity of interpretation. How lax
the interpretation really is, may be readily shown. When strata are
discontinuous, as between Europe and America, no evidence can be derived
from the order of superposition, apart from mineral characters and
organic remains; for, unless strata can be continuously traced, mineral
characters and organic remains afford the only means of classing them as
such or such. As to the test of mineral characters, we have seen that it
is almost worthless; and no modern geologist would dare to say it should
be relied on. If the Old Red Sandstone series in mid-England, differs
wholly in lithological aspect from the equivalent series in South Devon,
it is clear that similarities of texture and composition cannot justify
us in classing a system of strata in another quarter of the globe with
some European system. The test of fossils is the only one that remains;
and with how little strictness this test is applied, one case will show.
Of forty-six species of British Devonian corals, only six occur in
America; and this, notwithstanding the wide range which the _Anthozoa_
are known to have. Similarly of the _Mollusca_ and _Crinoidea_, it
appears that, while there are sundry genera found in America which are
found here, there are scarcely any of the same species. And Sir Charles
Lyell admits that "the difficulty of deciding on the exact parallelism
of the New York subdivisions, as above enumerated, with the members of
the European Devonian, is very great, so few are the species in common."
Yet it is on the strength of community of fossils, that the whole
Devonian series of the United States is assumed to be contemporaneous
with the whole Devonian series of England. And it is partly on the
ground that the Devonian of the United States corresponds in time with
our own Devonian, that Sir Charles Lyell concludes the superjacent
coal-measures of the two countries to be of the same age. Is it not,
then, as we said, that the evidence in these cases is very suspicious?
Should it be replied, as it may fairly be, that this correspondence from
which the synchronism of distant formations is inferred, is not a
correspondence between particular species or particular genera, but
between the general characters of the contained assemblages of
fossils--between the _facies_ of the two Faunas; the rejoinder is, that
though such correspondence is a stronger evidence of synchronism it is
still an insufficient one. To infer synchronism from such
correspondence, involves the postulate that throughout each geologic era
there has habitually existed a recognizable similarity between the
groups of organic forms inhabiting all the different parts of the Earth;
and that the causes which have in one part of the Earth changed the
organic forms into those which characterize the next era, have
simultaneously acted in all other parts of the Earth, in such ways as to
produce parallel changes of their organic forms. Now this is not only a
large assumption to make; but it is an assumption contrary to
probability. The probability is, that the causes which have changed
Faunas have been local rather than universal; that hence while the
Faunas of some regions have been rapidly changing, those of others have
been almost quiescent; and that when those of others have been changed,
it has been, not in such ways as to maintain parallelism, but in such
ways as to produce divergence.

Even supposing, however, that districts some hundreds of miles apart,
furnished groups of strata which completely agreed in their order of
superposition, their mineral characters, and their fossils, we should
still have inadequate proof of contemporaneity. For there are
conditions, very likely to occur, under which such groups might differ
widely in age. If there be a continent of which the strata crop out on
the surface obliquely to the line of coast--running, say,
west-north-west, while the coast runs east and west--it is clear that
each group of strata will crop out on the beach at a particular part of
the coast; that further west the next group of strata will crop out on
the beach; and so continuously. As the localization of marine plants and
animals, is in a considerable degree determined by the natures of the
rocks and their detritus, it follows that each part of this coast will
have its more or less distinct Flora and Fauna. What now must result
from the action of the waves in the course of a geologic epoch? As the
sea makes slow inroads on the land, the place at which each group of
strata crops out on the beach will gradually move towards the west: its
distinctive fish, mollusks, crustaceans, and sea-weeds, migrating with
it. Further, the detritus of each of these groups of strata will, as the
point of outcrop moves westwards, be deposited over the detritus of the
group in advance of it. And the consequence of these actions, carried on
for one of those enormous periods which a geologic change takes, will be
that, corresponding to each eastern stratum, there will arise a stratum
far to the west, which, though occupying the same position relatively to
other beds, formed of like materials, and containing like fossils, will
yet be perhaps a million years later in date.

       *       *       *       *       *

But the illegitimacy, or at any rate the great doubtfulness, of many
current geological inferences, is best seen when we contemplate
terrestrial changes now going on; and ask how far such inferences are
countenanced by them. If we carry out rigorously the modern method of
interpreting geological phenomena, which Sir Charles Lyell has done so
much to establish--that of referring them to causes like those at
present in action--we cannot fail to see how improbable are sundry of
the received conclusions.

Along each shore which is being worn away by the waves, there are being
formed mud, sand, and pebbles. This detritus has, in each locality, a
more or less special character; determined by the nature of the strata
destroyed. In the English Channel it is not the same as in the Irish
Channel; on the east coast of Ireland it is not the same as on the west
coast; and so throughout. At the mouth of each great river, there is
being deposited sediment differing more or less from that deposited at
the mouths of other rivers in colour and quality; forming strata which
are here red, there yellow, and elsewhere brown, grey, or dirty white.
Besides which various formations, going on in deltas and along shores,
there are some much wider, and still more strongly contrasted,
formations. At the bottom of the Ægean Sea, there is accumulating a bed
of Pteropod shells, which will eventually, no doubt, become a calcareous
rock. For some hundreds of thousands of square miles, the ocean-bed
between Great Britain and North America, is being covered with a stratum
of chalk; and over large areas in the Pacific, there are going on
deposits of coralline limestone. Thus, there are at this moment being
produced in different places multitudinous strata differing from one
another in lithological characters. Name at random any part of the
sea-bottom, and ask whether the deposit there taking place is like the
deposit taking place at some distant part of the sea-bottom, and the
almost-certainly correct answer will be--No. The chances are not in
favour of similarity, but against it--many to one against it.

In the order of superposition of strata there is being established a
like variety. Each region of the Earth's surface has its special history
of elevations, subsidences, periods of rest: and this history in no case
fits chronologically with the history of any other portion. River
deltas are now being thrown down on formations of different ages: some
very ancient, some quite modern. While here there has been deposited a
series of beds many hundreds of feet thick, there has elsewhere been
deposited but a single bed of fine mud. While one region of the Earth's
crust, continuing for a vast epoch above the surface of the ocean, bears
record of no changes save those resulting from denudation; another
region of the Earth's crust gives proof of sundry changes of level, with
their several resulting masses of stratified detritus. If anything is to
be judged from current processes, we must infer, not only that
everywhere the succession of sedimentary formations differs more or less
from the succession elsewhere; but also that in each place, there exist
groups of strata to which many other places have no equivalents.

With respect to the organic bodies imbedded in formations now in
progress, a like truth is equally manifest, if not more manifest. Even
along the same coast, within moderate distances, the forms of life
differ very considerably; and they differ much more on coasts that are
remote from one another. Again, dissimilar creatures which are living
together near the same shore, do not leave their remains in the same
beds of sediment. For instance, at the bottom of the Adriatic, where the
prevailing currents cause the deposits to be here of mud, and there of
calcareous matter, it is proved that different species of co-existing
shells are being buried in these respective formations. On our own
coasts, the marine remains found a few miles from shore, in banks where
fish congregate, are different from those found close to the shore,
where littoral species flourish. A large proportion of aquatic creatures
have structures which do not admit of fossilization; while of the rest,
the great majority are destroyed, when dead, by various kinds of
scavengers. So that no one deposit near our shores can contain anything
like a true representation of the Fauna of the surrounding sea; much
less of the co-existing Faunas of other seas in the same latitude; and
still less of the Faunas of seas in distant latitudes. Were it not that
the assertion seems needful, it would be almost absurd to say, that the
organic remains now being buried in the Dogger Bank, can tell us next to
nothing about the fish, crustaceans, mollusks, and corals, which are
being buried in the Bay of Bengal. Still stronger is the argument in the
case of terrestrial life. With more numerous and greater contrasts
between the types inhabiting one continent and those inhabiting another,
there is a far more imperfect registry of them. Schouw marks out on the
Earth more than twenty botanical regions, occupied by groups of forms so
distinct, that, if fossilized, geologists would scarcely be disposed to
refer them all to the same period. Of Faunas, the Arctic differs from
the Temperate; the Temperate from the Tropical; and the South Temperate
from the North Temperate. Nay, in the South Temperate Zone itself, the
two regions of South Africa and South America are unlike in their
mammals, birds, reptiles, fishes, mollusks, insects. The shells and
bones now lying at the bottoms of lakes and estuaries in these several
regions, have certainly not that similarity which is usually looked for
in those of contemporaneous strata; and the recent forms exhumed in any
one of these regions would very untruly represent the present Flora and
Fauna of the Earth. In conformity with the current style of geological
reasoning, an exhaustive examination of deposits in the Arctic circle,
might be held to prove that though at this period there were sundry
mammals existing, there were no reptiles; while the absence of mammals
in the deposits of the Galapagos Archipelago, where there are plenty of
reptiles, might be held to prove the reverse. And at the same time, from
the formations extending for two thousand miles along the great
barrier-reef of Australia--formations in which are imbedded nothing but
corals, echinoderms, mollusks, crustaceans, and fish, along with an
occasional turtle, or bird, or cetacean--it might be inferred that there
lived in our epoch neither terrestrial reptiles, nor terrestrial
mammals. The mention of Australia, indeed, suggests an illustration
which, even alone, would amply prove our case. The Fauna of this region
differs widely from any that is found elsewhere. On land, all the
indigenous mammals, except bats, belong to the lowest, or implacental
division; and the insects are singularly different from those found
elsewhere. The surrounding seas contain numerous forms which are more or
less strange; and among the fish there exists a species of shark, which
is the only living representative of a genus that flourished in early
geologic epochs. If, now, the modern fossiliferous deposits of Australia
were to be examined by one ignorant of the existing Australian Fauna;
and if he were to reason in the usual manner; he would be very unlikely
to class these deposits with those of the present time. How, then, can
we place confidence in the tacit assumption that certain formations in
remote parts of the Earth are referable to the same period, because the
organic remains contained in them display a certain community of
character? or that certain others are referable to different periods,
because the _facies_ of their Faunas are different?

"But," it will be replied, "in past eras the same, or similar, organic
forms were more widely distributed than now." It may be so; but the
evidence adduced by no means proves it. The argument by which this
conclusion is reached, runs a risk of being quoted as an example of
reasoning in a circle. As already pointed out, between formations in
remote regions the accepted test of equivalence is community of fossils.
If, then, the contemporaneity of remote formations is concluded from the
likeness of their fossils; how can it be said that similar plants and
animals were once more widely distributed, because they are found in
contemporaneous strata in remote regions? Is not the fallacy manifest?
Even supposing there were no such fatal objection as this, the evidence
commonly assigned would still be insufficient. For we must bear in mind
that the community of organic remains usually thought sufficient proof
of correspondence in time, is a very imperfect community. When the
compared sedimentary beds are far apart, it is scarcely expected that
there will be many species common to the two: it is enough if there be
discovered a considerable number of common genera. Now had it been
proved that throughout geologic time, each genus lived but for a short
period--a period measured by a single group of strata--something might
be inferred. But what if we learn that many of the same genera continued
to exist throughout enormous epochs, measured by several vast systems of
strata? "Among molluscs, the genera _Avicula_, _Modiola_, _Terebratula_,
_Lingula_, and _Orbicula_, are found from the Silurian rocks upwards to
the present day." If, then, between the lowest fossiliferous formations
and the most recent, there exists this degree of community; must we not
infer that there will probably often exist a great degree of community
between strata that are far from contemporaneous?

Thus the reasoning from which it is concluded that similar organic forms
were once more widely spread than now, is doubly fallacious; and,
consequently, the classifications of foreign strata based on the
conclusion are untrustworthy. Judging from the present distribution of
life, we cannot expect to find similar remains in geographically remote
strata of the same age; and where, between the fossils of geographically
remote strata, we do find much similarity, it is probably due rather to
likeness of conditions than to contemporaneity. If from causes and
effects such as we now witness, we reason back to the causes and effects
of past epochs, we discover inadequate warrant for sundry of the
received doctrines. Seeing, as we do, that in large areas of the Pacific
this is a period characterized by abundance of corals; that in the North
Atlantic it is a period in which a great chalk-deposit is being formed;
and that in the valley of the Mississippi it is a period of new
coal-basins--seeing also, as we do, that in one extensive continent this
is peculiarly an era of implacental mammals, and that in another
extensive continent it is peculiarly an era of placental mammals; we
have good reason to hesitate before accepting these sweeping
generalizations which are based on a cursory examination of strata
occupying but a tenth part of the Earth's surface.

       *       *       *       *       *

At the outset, this article was to have been a review of the works of
Hugh Miller; but it has grown into something much more general.
Nevertheless, the remaining two doctrines which we propose to criticize,
may conveniently be treated in connexion with his name, as that of one
who fully committed himself to them. And first, a few words respecting
his position.

That he was a man whose life was one of meritorious achievement, every
one knows. That he was a diligent and successful working geologist,
scarcely needs saying. That with indomitable perseverance he struggled
up from obscurity to a place in the world of literature and science,
shows him to have been highly endowed in character and intelligence. And
that he had a remarkable power of presenting his facts and arguments in
an attractive form, a glance at any of his books will quickly prove. By
all means, let us respect him as a man of activity and sagacity, joined
with a large amount of poetry. But while saying this we must add, that
his reputation stands by no means so high in the scientific world as in
the world at large. Partly from the fact that our Scotch neighbours are
in the habit of blowing the trumpet rather loudly before their
notabilities--partly because the charming style in which his books are
written has gained him a large circle of readers--partly, perhaps,
through a praiseworthy sympathy with him as a self-made man; Hugh Miller
has met with an amount of applause which, little as we wish to diminish
it, must not be allowed to blind the public to his defects as a man of
science. The truth is, he was so far committed to a foregone conclusion,
that he could not become a philosophical geologist. He might be aptly
described as a theologian studying geology. The dominant idea with which
he wrote, may be seen in the titles of two of his books--_Footprints of
the Creator_,--_The Testimony of the Rocks_. Regarding geological facts
as evidence for or against certain religious conclusions, it was
scarcely possible for him to deal with geological facts impartially. His
ruling aim was to disprove the Development Hypothesis, the assumed
implications of which were repugnant to him; and in proportion to the
strength of his feeling, was the one-sidedness of his reasoning. He
admitted that "God might as certainly have _originated_ the species by a
law of development, as he _maintains_ it by a law of development;--the
existence of a First Great Cause is as perfectly compatible with the one
scheme as with the other." Nevertheless, he considered the hypothesis at
variance with Christianity; and therefore combated with it. He
apparently overlooked the fact, that the doctrines of geology in
general, as held by himself, had been rejected by many on similar
grounds; and that he had himself been repeatedly attacked for his
anti-Christian teachings. He seems not to have perceived that, just as
his antagonists were wrong in condemning as irreligious, theories which
he saw were not irreligious; so might he be wrong in condemning, on like
grounds, the Theory of Evolution. In brief, he fell short of that
highest faith which knows that all truths must harmonize; and which is,
therefore, content trustfully to follow the evidence whithersoever it
leads.

Of course it is impossible to criticize his works without entering on
this great question to which he chiefly devoted himself. The two
remaining doctrines to be here discussed, bear directly on this
question; and, as above said, we propose to treat them in connexion with
Hugh Miller's name, because, throughout his reasonings, he assumes
their truth. Let it not be supposed, however, that we shall aim to
prove what he has aimed to disprove. While we purpose showing that his
geological arguments against the Development Hypothesis are based on
invalid assumptions; we do not purpose showing that the geological
arguments urged in support of it are based on valid assumptions. We hope
to make it apparent that the geological evidence at present obtained, is
insufficient for either side; further, that there seems little
probability that sufficient evidence will ever be obtained; and that if
the question is eventually decided, it must be decided on other than
geological grounds.

       *       *       *       *       *

The first of the current doctrines to which we have just referred, is,
that there occur in the serial records of former life on our planet, two
great blanks; whence it is inferred that, on at least two occasions, the
previously existing inhabitants of the Earth were almost wholly
destroyed, and a different class of inhabitants created. Comparing the
general life on the Earth to a thread, Hugh Miller says:--

     "It is continuous from the present time up to the commencement of
     the Tertiary period; and then so abrupt a break occurs, that, with
     the exception of the microscopic diatomaceæ, to which I last
     evening referred, and of one shell and one coral, not a single
     species crossed the gap. On its farther or remoter side, however,
     where the Secondary division closes, the intermingling of species
     again begins, and runs on till the commencement of this great
     Secondary division; and then, just where the Palæozoic division
     closes, we find another abrupt break, crossed, if crossed at
     all,--for there still exists some doubt on the subject,--by but two
     species of plant."

These breaks are supposed to imply actual new creations on the surface
of our planet--supposed not by Hugh Miller only, but by the majority of
geologists. And the terms Palæozoic, Mesozoic, and Cainozoic, are used
to indicate these three successive systems of life. It is true that some
accept this belief with caution; knowing how geologic research has been
all along tending to fill up what were once thought wide gaps. Sir
Charles Lyell points out that "the hiatus which exists in Great Britain
between the fossils of the Lias and those of the Magnesian Limestone,
is supplied in Germany by the rich fauna and flora of the Muschelkalk,
Keuper, and Bunter Sandstein, which we know to be of a date precisely
intermediate." Again he remarks that "until lately the fossils of the
coal-measures were separated from those of the antecedent Silurian group
by a very abrupt and decided line of demarcation; but recent discoveries
have brought to light in Devonshire, Belgium, the Eifel, and Westphalia,
the remains of a fauna of an intervening period." And once more, he
says, "we have also in like manner had some success of late years in
diminishing the hiatus which still separates the Cretaceous and Eocene
periods in Europe." To which let us add that, since Hugh Miller penned
the passage above quoted, the second of the great gaps he refers to has
been very considerably narrowed by the discovery of strata containing
Palæozoic genera and Mesozoic genera intermingled. Nevertheless, the
occurrence of two great revolutions in the Earth's Flora and Fauna
appears still to be held by many; and geologic nomenclature habitually
assumes it.

Before seeking a solution of the problem thus raised, let us glance at
the several minor causes which produce breaks in the geological
succession of organic forms; taking first, the more general ones which
modify climate, and, therefore, the distribution of life. Among these
may be noted one which has not, we believe, been named by writers on the
subject. We mean that resulting from a certain slow astronomic rhythm,
by which the northern and southern hemispheres are alternately subject
to greater extremes of temperature. In consequence of the slight
ellipticity of its orbit, the Earth's distance from the sun varies to
the extent of some 3,000,000 of miles. At present, the aphelion occurs
at the time of our northern summer; and the perihelion during the summer
of the southern hemisphere. In consequence, however, of that slow
movement of the Earth's axis which produces the precession of the
equinoxes, this state of things will in time be reversed: the Earth
will be nearest to the sun during the summer of the northern hemisphere,
and furthest from it during the southern summer or northern winter. The
period required to complete the slow movement producing these changes,
is nearly 26,000 years; and were there no modifying process, the two
hemispheres would alternately experience this coincidence of summer with
relative nearness to the sun, during a period of 13,000 years. But there
is also a still slower change in the direction of the axis major of the
Earth's orbit; from which it results that the alternation we have
described is completed in about 21,000 years. That is to say, if at a
given time the Earth is nearest to the sun at our mid-summer, and
furthest from the sun at our mid-winter; then, in 10,500 years
afterwards, it will be furthest from the sun at our mid-summer, and
nearest at our mid-winter. Now the difference between the distances from
the sun at the two extremes of this alternation, amounts to
one-thirtieth; and hence, the difference between the quantities of heat
received from the sun on a summer's day under these opposite conditions
amounts to one-fifteenth. Estimating this, not with reference to the
zero of our thermometers, but with reference to the temperature of the
celestial spaces, Sir John Herschel calculates "23° Fahrenheit, as the
least variation of temperature under such circumstances which can
reasonably be attributed to the actual variation of the sun's distance."
Thus, then, each hemisphere has at a certain epoch, a short summer of
extreme heat, followed by a long and very cold winter. Through the slow
change in the direction of the Earth's axis, these extremes are
gradually mitigated. And at the end of 10,500 years, there is reached
the opposite state--a long and moderate summer, with a short and mild
winter. At present, in consequence of the predominance of sea in the
southern hemisphere, the extremes to which its astronomical conditions
subject it, are much ameliorated; while the great proportion of land in
the northern hemisphere, tends to exaggerate such contrast as now
exists in it between winter and summer: whence it results that the
climates of the two hemispheres are not widely unlike. But 10,000 years
hence, the northern hemisphere will undergo annual variations of
temperature far more marked than now.

In the last edition of his _Outlines of Astronomy_, Sir John Herschel
recognizes this as an element in geological processes; regarding it as
possibly a part-cause of those climatic changes indicated by the records
of the Earth's past. That it has had much to do with those larger
changes of climate of which we have evidence, seems unlikely, since
there is reason to think that these have been far slower and more
lasting; but that it must have entailed a rhythmical exaggeration and
mitigation of the climates otherwise produced, seems beyond question.
And it seems also beyond question that there must have been a consequent
rhythmical change in the distribution of organisms--a rhythmical change
to which we here wish to draw attention, as one cause of minor breaks in
the succession of fossil remains. Each species of plant and animal has
certain limits of heat and cold within which only it can exist; and
these limits in a great degree determine its geographical position. It
will not spread north of a certain latitude, because it cannot bear a
more northern winter, nor south of a certain latitude, because the
summer heat is too great; or else it is indirectly restrained from
spreading further by the effect of temperature on the humidity of the
air, or on the distribution of the organisms it lives upon. But now,
what will result from a slow alteration of climate, produced as above
described? Supposing the period we set out from is that in which the
contrast of seasons is least marked, it is manifest that during the
progress towards the period of most violent contrast, each species of
plant and animal will gradually change its limits of distribution--will
be driven back, here by the winter's increasing cold, and there by the
summer's increasing heat--will retire into those localities that are
still fit for it. Thus during 10,000 years, each species will ebb away
from certain regions it was inhabiting; and during the succeeding 10,000
years will flow back into those regions. From the strata there forming,
its remains will disappear; they will be absent from some of the
superposed strata; and will be found in strata higher up. But in what
shapes will they re-appear? Exposed during the 21,000 years of their
slow recession and their slow return, to changing conditions of life,
they are likely to have undergone modifications; and will probably
re-appear with slight differences of constitution and perhaps of
form--will be new varieties or perhaps new sub-species.

To this cause of minor breaks in the succession of organic forms--a
cause on which we have dwelt because it has not been taken into
account--we must add sundry others. Besides these periodically-recurring
changes of climate, there are the irregular ones produced by
redistributions of land and sea; and these, sometimes less, sometimes
greater, in degree, than the rhythmical changes, must, like them, cause
in each region emigrations and immigrations of species; and consequent
breaks, small or large as the case may be, in the paleontological
series. Other and more special geological changes must produce other and
more local blanks in the succession. By some inland elevation the
natural drainage of a continent is modified; and instead of the sediment
previously brought down to the sea by it, a great river brings down
sediment unfavourable to various plants and animals living in its delta:
whereupon these disappear from the locality, perhaps to re-appear in a
changed form after a long epoch. Upheavals or subsidences of shores or
sea-bottoms, involving deviations of marine currents, remove the
habitats of many species to which such currents are salutary or
injurious; and further, this redistribution of currents alters the
places of sedimentary deposits, and thus stops the burying of organic
remains in some localities, while commencing it in others. Had we space,
many more such causes of blanks in our paleontological records might be
added. But it is needless here to enumerate them. They are admirably
explained and illustrated in Sir Charles Lyell's _Principles of
Geology_.

Now, if these minor changes of the Earth's surface produce minor breaks
in the series of fossilized remains; must not great changes produce
great breaks? If a local upheaval or subsidence causes throughout its
small area the absence of some links in the chain of fossil forms; does
it not follow that an upheaval or subsidence extending over a large part
of the Earth's surface, must cause the absence of a great number of such
links throughout a very wide area?

When during a long epoch a continent, slowly sinking, gives place to a
far-spreading ocean some miles in depth, at the bottom of which no
deposits from rivers or abraded shores can be thrown down; and when,
after some enormous period, this ocean-bottom is gradually elevated and
becomes the site for new strata; it is clear that the fossils contained
in these new strata are likely to have but little in common with the
fossils of the strata below them. Take, in illustration, the case of the
North Atlantic. We have already named the fact that between this country
and the United States, the ocean-bottom is being covered with a deposit
of chalk--a deposit which has been forming, probably, ever since there
occurred that great depression of the Earth's crust from which the
Atlantic resulted in remote geologic times. This chalk consists of the
minute shells of _Foraminifera_, sprinkled with remains of small
_Entomostraca_, and probably a few Pteropod-shells; though the sounding
lines have not yet brought up any of these last. Thus, in so far as all
high forms of life are concerned, this new chalk-formation must be a
blank. At rare intervals, perhaps, a polar bear, drifted on an iceberg,
may have its bones scattered over the bed; or a dead, decaying whale
may similarly leave traces. But such remains must be so rare, that this
new chalk-formation, if accessible, might be examined for a century
before any of them were disclosed. If now, some millions of years hence,
the Atlantic-bed should be raised, and estuary deposits or shore
deposits laid upon it, these would contain remains of a Flora and a
Fauna so distinct from everything below them, as to appear like a new
creation.

Thus, along with continuity of life on the Earth's surface, there not
only _may_ be, but there _must_ be, great gaps in the series of fossils;
and hence these gaps are no evidence against the doctrine of Evolution.

       *       *       *       *       *

One other current assumption remains to be criticized; and it is the one
on which, more than on any other, depends the view taken respecting the
question of development.

From the beginning of the controversy, the arguments for and against
have turned upon the evidence of progression in organic forms, found in
the ascending series of our sedimentary formations. On the one hand,
those who contend that higher organisms have been evolved out of lower,
joined with those who contend that successively higher organisms have
been created at successively later periods, appeal for proof to the
facts of Paleontology; which, they say, countenance their views. On the
other hand, the Uniformitarians, who not only reject the hypothesis of
development, but deny that the modern forms of life are higher than the
ancient ones, reply that the paleontological evidence is at present very
incomplete; that though we have not yet found remains of
highly-organized creatures in strata of the greatest antiquity, we must
not assume that no such creatures existed when those strata were
deposited; and that, probably, search will eventually disclose them.

It must be admitted that thus far, the evidence has gone in favour of
the latter party. Geological discovery has year after year shown the
small value of negative facts. The conviction that there are no traces
of higher organisms in earlier strata, has resulted not from the absence
of such traces, but from incomplete examination. At p. 460 of his
_Manual of Elementary Geology_, Sir Charles Lyell gives a list in
illustration of this. It appears that in 1709, fishes were not known
lower than the Permian system. In 1793 they were found in the subjacent
Carboniferous system; in 1828 in the Devonian; in 1840 in the Upper
Silurian. Of reptiles, we read that in 1710 the lowest known were in the
Permian; in 1844 they were detected in the Carboniferous; and in 1852 in
the Upper Devonian. While of the Mammalia the list shows that in 1798
none had been discovered below the Middle Eocene: but that in 1818 they
were discovered in the Lower Oolite; and in 1847 in the Upper Trias.

The fact is, however, that both parties set out with an inadmissible
postulate. Of the Uniformitarians, not only such writers as Hugh Miller,
but also such as Sir Charles Lyell,[27] reason as though we had found
the earliest, or something like the earliest, strata. Their antagonists,
whether defenders of the Development Hypothesis or simply
Progressionists, almost uniformly do the like. Sir R. Murchison, who is
a Progressionist, calls the lowest fossiliferous strata, "Protozoic."
Prof. Ansted uses the same term. Whether avowedly or not, all the
disputants stand on this assumption as their common ground.

Yet is this assumption indefensible, as some who make it very well know.
Facts may be cited against it which show that it is a more than
questionable one--that it is a highly improbable one; while the evidence
assigned in its favour will not bear criticism.

Because in Bohemia, Great Britain, and portions of North America, the
lowest unmetamorphosed strata yet discovered, contain but slight traces
of life, Sir R. Murchison conceives that they were formed while yet few,
if any, plants or animals had been created; and, therefore, classes them
as "Azoic." His own pages, however, show the illegitimacy of the
conclusion that there existed at that period no considerable amount of
life. Such traces of life as have been found in the Longmynd rocks, for
many years considered unfossiliferous, have been found in some of the
lowest beds; and the twenty thousand feet of superposed beds, still
yield no organic remains. If now these superposed strata throughout a
depth of four miles, are without fossils, though the strata over which
they lie prove that life had commenced; what becomes of Sir R.
Murchison's inference? At page 189 of _Siluria_, a still more conclusive
fact will be found. The "Glengariff grits," and other accompanying
strata there described as 13,500 feet thick, contain no signs of
contemporaneous life. Yet Sir R. Murchison refers them to the Devonian
period--a period which had a large and varied marine Fauna. How then,
from the absence of fossils in the Longmynd beds and their equivalents,
can we conclude that the Earth was "azoic" when they were formed?

"But," it may be asked, "if living creatures then existed, why do we not
find fossiliferous strata of that age, or an earlier age?" One reply is,
that the non-existence of such strata is but a negative fact--we have
not found them. And considering how little we know even of the
two-fifths of the Earth's surface now above the sea, and how absolutely
ignorant we are of the three-fifths below the sea, it is rash to say
that no such strata exist. But the chief reply is, that these records of
the Earth's earlier history have been in great part destroyed, by
agencies which are ever tending to destroy such records.

It is an established geological doctrine, that sedimentary strata are
liable to be changed, more or less profoundly, by igneous action. The
rocks originally classed as "transition," because they were
intermediate in character between the igneous rocks found below them,
and the sedimentary strata found above them, are now known to be nothing
else than sedimentary strata altered in texture and appearance by the
intense heat of adjacent molten matter; and hence are renamed
"metamorphic rocks." Modern researches have shown, too, that these
metamorphic rocks are not, as was once supposed, all of the same age.
Besides primary and secondary strata which have been transformed by
igneous action, there are similarly-changed deposits of tertiary
origin--deposits changed, even as far as a quarter of a mile from the
point of contact with neighbouring granite. By this process fossils are
of course destroyed. "In some cases," says Sir Charles Lyell, "dark
limestones, replete with shells and corals, have been turned into white
statuary marble, and hard clays, containing vegetable or other remains,
into slates called mica-schist or hornblende-schist; every vestige of
the organic bodies having been obliterated." Again, it is fast becoming
an acknowledged truth that igneous rock, of whatever kind, is the
product of sedimentary strata which have been completely melted. Granite
and gneiss, which are of like chemical composition, have been shown, in
various cases, to pass one into the other; as at Valorsine, near Mont
Blanc, where the two, in contact, are observed to "both undergo a
modification of mineral character. The granite still remaining
unstratified, becomes charged with green particles; and the talcose
gneiss assumes a granitiform structure without losing its
stratification." In the Aberdeen-granite, lumps of unmelted gneiss are
abundant; and we can ourselves bear witness that the granite on the
banks of Loch Sunart yields proofs that, when molten, it contained
incompletely-fused clots of sedimentary strata. Nor is this all. Fifty
years ago, it was thought that all granitic rocks were primitive, or
existed before any sedimentary strata; but it is now "no easy task to
point out a single mass of granite demonstrably more ancient than all
the known fossiliferous deposits." In brief, accumulated evidence shows,
that by contact with, or proximity to, the molten matter of the Earth's
nucleus, all beds of sediment are liable to be actually melted, or
partially fused, or so heated as to agglutinate their particles; and
that according to the temperature they have been raised to, and the
circumstances under which they cool, they assume the forms of granite,
porphyry, trap, gneiss, or rock otherwise altered. Further, it is
manifest that though strata of various ages have been thus changed, yet
the most ancient strata have been so changed to the greatest extent;
both because they have been nearer to the centre of igneous agency; and
because they have been for longer periods liable to be affected by it.
Whence it follows, that sedimentary strata passing a certain antiquity,
are unlikely to be found in an unmetamorphosed state; and that strata
much earlier than these are certain to have been melted up. Thus if,
throughout a past of indefinite duration, there had been at work those
aqueous and igneous agencies which we see still at work, the state of
the Earth's crust might be just what we find it. We have no evidence
which puts a limit to the period throughout which this formation and
destruction of strata has been going on. For aught the facts prove, it
may have been going on for ten times the period measured by our whole
series of sedimentary deposits.

Besides having, in the present appearances of the Earth's crust, no data
for fixing a commencement to these processes--besides finding that the
evidence permits us to assume such commencement to have been
inconceivably remote, as compared even with the vast eras of geology; we
are not without positive grounds for inferring the inconceivable
remoteness of such commencement. Modern geology has established truths
which are irreconcilable with the belief that the formation and
destruction of strata began when the Cambrian rocks were formed; or at
anything like so recent a time. One fact from _Siluria_ will suffice.
Sir R. Murchison estimates the vertical thickness of Silurian strata in
Wales, at from 26,000 to 27,000 feet, or about five miles; and if to
this we add the vertical depth of the Cambrian strata, on which the
Silurians lie conformably, there results, on the lowest computation, a
total depth of some seven miles. Now it is held by geologists, that this
vast series of formations must have been deposited in an area of gradual
subsidence. These beds could not have been thus laid one on another in
regular order, unless the Earth's crust had been at that place sinking,
either continuously or by small steps. Such an immense subsidence,
however, must have been impossible without a crust of great thickness.
The Earth's molten nucleus tends ever, with enormous force, to assume
the form of a regular oblate spheroid. Any depression of its crust below
the surface of equilibrium, and any elevation of its crust above that
surface, have to withstand immense resistances. It follows inevitably
that, with a thin crust, nothing but small elevations and subsidences
would have been possible; and that, conversely, a subsidence of seven
miles implies a crust of great strength, or, in other words, of great
thickness. Indeed, if we compare this inferred subsidence in the
Silurian period, with such elevations and depressions as our existing
continents and oceans display, we see no evidence that the Earth's crust
was appreciably thinner then than now. What are the implications? If, as
geologists generally admit, the Earth's crust has resulted from that
slow cooling which is even still going on--if we see no sign that at the
time when the earliest Cambrian strata were formed, this crust was
appreciably thinner than now; we are forced to conclude that the era
during which it acquired that great thickness possessed in the Cambrian
period, was enormous as compared with the interval between the Cambrian
period and our own. But during the incalculable series of epochs thus
implied, there existed an ocean, tides, winds, waves, rain, rivers. The
agencies by which the denudation of continents and filling up of seas
have all along been carried on, were as active then as now. Endless
successions of strata must have been formed. And when we ask--Where are
they? Nature's obvious reply is--They have been destroyed by that
igneous action to which so great a part of our oldest-known strata owe
their fusion or metamorphosis.

Only the last chapter of the Earth's history has come down to us. The
many previous chapters, stretching back to a time immeasurably remote,
have been burnt; and with them all the records of life we may presume
they contained. The greater part of the evidence which might have served
to settle the Development-controversy, is for ever lost; and on neither
side can the arguments derived from Geology be conclusive.

"But how happen there to be such evidences of progression as exist?" it
may be asked. "How happens it that, in ascending from the most ancient
strata to the most recent strata, we _do_ find a succession of organic
forms, which, however irregularly, carries us from lower to higher?"
This question seems difficult to answer. Nevertheless, there is reason
for thinking that nothing can be safely inferred from the apparent
progression here cited. And the illustration which shows as much, will,
we believe, also show how little trust is to be placed in certain
geological generalizations that appear to be well established. With this
somewhat elaborate illustration, to which we now pass, our criticisms
may fitly conclude.

       *       *       *       *       *

Let us suppose that in a region now covered by wide ocean, there begins
one of those great and gradual upheavals by which new continents are
formed. To be precise, let us say that in the South Pacific, midway
between New Zealand and Patagonia, the sea-bottom has been little by
little thrust up toward the surface, and is about to emerge. What will
be the successive phenomena, geological and biological, which are
likely to occur before this emerging sea-bottom has become another
Europe or Asia? In the first place, such portions of the incipient land
as are raised to the level of the waves, will be rapidly denuded by
them: their soft substance will be torn up by the breakers, carried away
by the local currents, and deposited in neighbouring deeper water.
Successive small upheavals will bring new and larger areas within reach
of the waves; fresh portions will each time be removed from the surfaces
previously denuded; and further, some of the newly-formed strata, being
elevated nearly to the level of the water, will be washed away and
re-deposited. In course of time the harder formations of the upraised
sea-bottom will be uncovered. These, being less easily destroyed, will
remain permanently above the surface; and at their margins will arise
the usual breaking down of rocks into beach-sand and pebbles. While in
the slow course of this elevation, going on at the rate of perhaps two
or three feet in a century, most of the sedimentary deposits produced
will be again and again destroyed and reformed; there will, in those
adjacent areas of subsidence which accompany areas of elevation, be more
or less continuous successions of sedimentary deposits lying on the
pre-existing ocean bed. And now, what will be the character of these
strata, old and new? They will contain scarcely any traces of life. The
deposits that had previously been slowly formed at the bottom of this
wide ocean, would be sprinkled with fossils of but few species. The
oceanic Fauna is not a rich one; its hydrozoa do not admit of
preservation; and the hard parts of its few kinds of molluscs and
crustaceans and insects are mostly fragile. Hence, when the ocean-bed
was here and there raised to the surface--when its strata of sediment
with their contained organic fragments were torn up and long washed
about by the breakers before being re-deposited--when the re-deposits
were again and again subject to this violent abrading action by
subsequent small elevations, as they would mostly be; what few fragile
organic remains they contained, would be in nearly all cases destroyed.
Thus such of the first-formed strata as survived the repeated changes of
level, would be practically "azoic;" like the Cambrian of our
geologists. When by the washing away of the soft deposits, the hard
sub-strata had been exposed in the shape of rocky islets, and a footing
had thus been furnished, the pioneers of a new life might be expected to
make their appearance. What would they be? Not any of the surrounding
oceanic species, for these are not fitted for a littoral life; but
species flourishing on some of the far-distant shores of the Pacific. Of
such, the first to establish themselves would be sea-weeds and
zoophytes; because the most readily conveyed on floating wood, &c., and
because when conveyed they would find fit food. It is true that
Cirrhipeds and Lamellibranchs, subsisting on the minute creatures which
everywhere people the sea, would also find fit food. But the chances of
early colonization are in favour of species which, multiplying by
agamogenesis, can people a whole shore from a single germ; and against
species which, multiplying only by gamogenesis, must be introduced in
considerable numbers that some may propagate. Thus we infer that the
earliest traces of life left in the sedimentary deposits near these new
shores, will be traces of life as humble as that indicated in the most
ancient rocks of Great Britain and Ireland. Imagine now that the
processes above indicated, continue--that the emerging lands become
wider in extent, and fringed by higher and more varied shores; and that
there still go on those ocean-currents which, at long intervals, convey
from far distant shores immigrant forms of life. What will result? Lapse
of time will of course favour the introduction of such new forms:
admitting, as it must, of those combinations of fit conditions, which
can occur only after long intervals. Moreover, the increasing area of
the islands, individually and as a group, implies increasing length of
coast, and therefore a longer line of contact with the streams and waves
which bring drifting masses bearing germs of fresh life. And once more,
the comparatively-varied shores, presenting physical conditions which
change from mile to mile, will furnish suitable habitats for more
numerous species. So that as the elevation proceeds, three causes
conspire to introduce additional marine plants and animals. To what
classes will the increasing Fauna be for a long period confined? Of
course, to classes of which individuals, or their germs, are most liable
to be carried far away from their native shores by floating sea-weed or
drift-wood; to classes which are also least likely to perish in transit,
or from change of climate; and to those which can best subsist around
coasts comparatively bare of life. Evidently then, corals, annelids,
inferior molluscs, and crustaceans of low grade, will chiefly constitute
the early Fauna. The large predatory members of these classes, will be
later in establishing themselves; both because the new shores must first
become well peopled by the creatures they prey on, and because, being
more complex, they, or their ova, must be less likely to survive the
journey, and the change of conditions. We may infer, then, that the
strata deposited next after the almost "azoic" strata, would contain the
remains of invertebrata, allied to those found near the shores of
Australia and South America. Of such invertebrate remains, the lower
beds would furnish comparatively few genera, and those of relatively low
types; while in the upper beds the number of genera would be greater,
and the types higher: just as among the fossils of our Silurian system.
As this great geologic change slowly advanced through its long history
of earthquakes, volcanic disturbances, minor upheavals and
subsidences--as the extent of the archipelago became greater and its
smaller islands coalesced into larger ones, while its coast-line grew
still longer and more varied, and the neighbouring sea more thickly
inhabited by inferior forms of life; the lowest division of the
vertebrata would begin to be represented. In order of time, fish would
naturally come later than the lower invertebrata; both as being less
likely to have their ova transported across the waste of waters, and as
requiring for their subsistence a pre-existing Fauna of some
development. They might be expected to make their appearance along with
the predaceous crustaceans; as they do in the uppermost Silurian rocks.
And here, too, let us remark, that as, during this long epoch we have
been describing, the sea would have made great inroads on some of the
newly-raised lands which had remained stationary; and would probably in
some places have reached masses of igneous or metamorphic rocks; there
might, in course of time, arise by the decomposition and denudation of
such rocks, local deposits coloured with oxide of iron, like our Old Red
Sandstone. And in these deposits might be buried the remains of the fish
then peopling the neighbouring sea.

Meanwhile, how would the surfaces of the upheaved masses be occupied? At
first their deserts of naked rocks would bear only the humblest forms of
vegetal life, such as we find in grey and orange patches on our own
rugged mountain sides; for these alone could flourish on such surfaces,
and their spores would be the most readily transported. When, by the
decay of such protophytes, and that decomposition of rock effected by
them, there had resulted a fit habitat for mosses; these, of which the
germs might be conveyed in drifted trees, would begin to spread. A soil
having been eventually thus produced, it would become possible for
plants of higher organization to find roothold; and as the archipelago
and its constituent islands grew larger, and had more multiplied
relations with winds and waters, such higher plants might be expected
ultimately to have their seeds transferred from the nearest lands. After
something like a Flora had thus colonized the surface, it would become
possible for insects to exist; and of air-breathing creatures, insects
would manifestly be among the first to find their way from elsewhere.
As, however, terrestrial organisms, both vegetal and animal, are less
likely than marine organisms to survive the accidents of transport from
distant shores; it is inferable that long after the sea surrounding
these new lands had acquired a varied Flora and Fauna, the lands
themselves would still be comparatively bare; and thus that the early
strata, like our Silurians, would afford no traces of terrestrial life.
By the time that large areas had been raised above the ocean, we may
fairly suppose a luxuriant vegetation to have been acquired. Under what
circumstances are we likely to find this vegetation fossilized? Large
surfaces of land imply large rivers with their accompanying deltas; and
are liable to have lakes and swamps. These, as we know from extant
cases, are favourable to rank vegetation; and afford the conditions
needful for preserving it in coal-beds. Observe, then, that while in the
early history of such a continent a carboniferous period could not
occur, the occurrence of a carboniferous period would become probable
after long-continued upheavals had uncovered large areas. As in our own
sedimentary series, coal-beds would make their appearance only after
there had been enormous accumulations of earlier strata charged with
marine fossils.

Let us ask next, in what order the higher forms of animal life would
make their appearance. We have seen how, in the succession of marine
forms, there would be something like a progress from the lower to the
higher: bringing us in the end to predaceous molluscs, crustaceans, and
fish. What are likely to succeed fish? After marine creatures, those
which would have the greatest chance of surviving the voyage would be
amphibious reptiles; both because they are more tenacious of life than
higher animals, and because they would be less completely out of their
element. Such reptiles as can live in both fresh and salt water, like
alligators; and such as are drifted out of the mouths of great rivers on
floating trees, as Humboldt says the Orinoco alligators are; might be
early colonists. It is manifest, too, that reptiles of other kinds would
be among the first vertebrata to people the new continent. If we
consider what will occur on one of those natural rafts of trees, soil,
and matted vegetable matter, sometimes swept out to sea by such currents
as the Mississippi, with a miscellaneous living cargo; we shall see that
while the active, hot-blooded, highly-organized creatures will soon die
of starvation and exposure, the inert, cold-blooded ones, which can go
long without food, will live perhaps for weeks; and so, out of the
chances from time to time occurring during long periods, reptiles will
be the first to get safely landed on foreign shores: as indeed they are
even now known sometimes to be. The transport of mammalia being
comparatively precarious, must, in the order of probability, be longer
postponed; and would, indeed, be unlikely to occur until by the
enlargement of the new continent, the distances of its shores from
adjacent lands had been greatly diminished, or the formation of
intervening islands had increased the chances of survival. Assuming,
however, that the facilities for immigration had become adequate; which
would be the first mammals to arrive and live? Not large herbivores; for
they would be soon drowned if by any accident carried out to sea. Not
the carnivora; for these would lack appropriate food, even if they
outlived the voyage. Small quadrupeds frequenting trees, and feeding on
insects, would be those most likely both to be drifted away from their
native lands and to find fit food in a new one. Insectivorous mammals,
like in size to those found in the Trias and the Stonesfield slate,
might naturally be looked for as the pioneers of the higher vertebrata.
And if we suppose the facilities of communication to be again increased,
either by a further shallowing of the intervening sea and a consequent
multiplication of islands, or by an actual junction of the new continent
with an old one, through continued upheavals; we should finally have an
influx of the larger and more perfect mammals.

Now rude as is this sketch of a process that would be extremely
elaborate and involved, and open as some of its propositions are to
criticisms which there is no space here to meet; no one will deny that
it represents something like the biologic history of the supposed new
continent. Details apart, it is manifest that simple organisms, able to
flourish under simple conditions of life, would be the first successful
immigrants; and that more complex organisms, needing for their existence
the fulfilment of more complex conditions, would afterwards establish
themselves in something like an ascending succession. At the one extreme
we see every facility. The new individuals can be conveyed in the shape
of minute germs; immense numbers of these are perpetually being carried
in all directions to great distances by ocean-currents--either detached
or attached to floating bodies; they can find nutriment wherever they
arrive; and the resulting organisms can multiply asexually with great
rapidity. At the other extreme, we see every difficulty. The new
individuals must be conveyed in their adult forms; their numbers are, in
comparison, utterly insignificant; they live on land, and are very
unlikely to be carried out to sea; when so carried, the chances are
immense against their escape from drowning, starvation, or death by
cold; if they survive the transit, they must have a pre-existing Flora
or Fauna to supply their special food; they require, also, the
fulfilment of various other physical conditions; and unless at least two
individuals of different sexes are safely landed, the race cannot be
established. Manifestly, then, the immigration of each successively
higher order of organisms, having, from one or other additional
condition to be fulfilled, an enormously-increased probability against
it, would naturally be separated from the immigration of a lower order
by some period like a geologic epoch. And thus the successive
sedimentary deposits formed while this new continent was undergoing
gradual elevation, would seem to furnish clear evidence of a general
progress in the forms of life. That lands thus raised up in the midst of
a wide ocean, would first give origin to unfossiliferous strata; next,
to strata containing only the lowest marine forms; next to strata
containing only the higher marine forms, ascending finally to fish; and
that the strata above these would contain reptiles, then small mammals,
then great mammals; seems to us demonstrable. And if the succession of
fossils presented by the strata of this supposed new continent, would
thus simulate the succession presented by our own sedimentary series;
must we not conclude that our own sedimentary series very possibly
records nothing more than the phenomena accompanying one of these great
upheavals? The probability of this conclusion being admitted, it must be
admitted that the facts of Paleontology can never suffice either to
prove or disprove the Development Hypothesis; but that the most they can
do is to show whether the last few pages of the Earth's biologic
history, are or are not in harmony with this hypothesis--whether the
existing Flora and Fauna can or can not be affiliated upon the Flora and
Fauna of the most recent geologic times.

FOOTNOTE:

[Footnote 27: Sir Charles Lyell is no longer to be classed among
Uniformitarians. With rare and admirable candour he has, since this was
written, yielded to the arguments of Mr. Darwin.]




BAIN ON THE EMOTIONS AND THE WILL.

    [_First published in_ The Medico-Chirurgical Review _for January,_
    1860.]


After the controversy between the Neptunists and the Vulcanists had been
long carried on without definite results, there came a reaction against
all speculative geology. Reasoning without adequate data having led to
nothing, inquirers went into the opposite extreme, and confining
themselves wholly to collecting data, relinquished reasoning. The
Geological Society of London was formed with the express object of
accumulating evidence; for many years hypotheses were forbidden at its
meetings: and only of late have attempts to organize the mass of
observations into consistent theory been tolerated.

This reaction and subsequent re-reaction, well illustrate the recent
history of English thought in general. The time was when our countrymen
speculated, certainly to as great an extent as any other people, on all
those high questions which present themselves to the human intellect;
and, indeed, a glance at the systems of philosophy that are or have been
current on the Continent, suffices to show how much other nations owe to
the discoveries of our ancestors. For a generation or two, however,
these more abstract subjects have fallen into neglect; and, among those
who plume themselves on being "practical," even into contempt. Partly,
perhaps, a natural accompaniment of our rapid material growth, this
intellectual phase has been in great measure due to the exhaustion of
argument, and the necessity for better data. Not so much with a
conscious recognition of the end to be subserved, as from an unconscious
subordination to that rhythm traceable in social changes as in other
things, an era of theorizing without observing, has been followed by an
era of observing without theorizing. During this long-continued devotion
to concrete science, an immense quantity of raw material for abstract
science has been accumulated; and now there is obviously commencing a
period in which this accumulated raw material will be organized into
consistent theory. On all sides--equally in the inorganic sciences, in
the science of life, and in the science of society--we may note the
tendency to pass from the superficial and empirical to the more profound
and rational.

In Psychology this change is conspicuous. The facts brought to light by
anatomists and physiologists during the last fifty years, are at length
being used towards the interpretation of this highest class of
biological phenomena; and already there is promise of a great advance.
The work of Mr. Alexander Bain, of which the second volume has been
recently issued, may be regarded as especially characteristic of the
transition. It gives us, in orderly arrangement, the great mass of
evidence supplied by modern science towards the building-up of a
coherent system of mental philosophy. It is not in itself a system of
mental philosophy, properly so called; but a classified collection of
materials for such a system, presented with that method and insight
which scientific discipline generates, and accompanied with occasional
passages of an analytical character. It is indeed that which it in the
main professes to be--a natural history of the mind. Were we to say that
the researches of the naturalist who collects and dissects and describes
species, bear the same relation to the researches of the comparative
anatomist tracing out the laws of organization, which Mr. Bain's
labours bear to the labours of the abstract psychologist, we should be
going somewhat too far; for Mr. Bain's work is not wholly descriptive.
Still, however, such an analogy conveys the best general conception of
what he has done; and serves most clearly to indicate its needfulness.
For as, before there can be made anything like true generalizations
respecting the classification of organisms and the laws of organization,
there must be an extensive accumulation of the facts presented in
numerous organic bodies; so, without a tolerably-complete delineation of
mental phenomena of all orders, there can scarcely arise any adequate
theory of mind. Until recently, mental science has been pursued much as
physical science was pursued by the ancients; not by drawing conclusions
from observations and experiments, but by drawing them from arbitrary _a
priori_ assumptions. This course, long since abandoned in the one case
with immense advantage, is gradually being abandoned in the other; and
the treatment of Psychology as a division of natural history, shows that
the abandonment will soon be complete.

Estimated as a means to higher results, Mr. Bain's work is of great
value. Of its kind it is the most scientific in conception, the most
catholic in spirit, and the most complete in execution. Besides
delineating the various classes of mental phenomena as seen under that
stronger light thrown on them by modern science, it includes in the
picture much which previous writers had omitted--partly from prejudice,
partly from ignorance. We refer more especially to the participation of
bodily organs in mental changes; and the addition to the primary mental
changes, of those many secondary ones which the actions of the bodily
organs generate. Mr. Bain has, we believe, been the first to appreciate
the importance of this element in our states of consciousness; and it is
one of his merits that he shows how constant and large an element it is.
Further, the relations of voluntary and involuntary movements are
elucidated in a way that was not possible to writers unacquainted with
the modern doctrine of reflex action. And beyond this, some of the
analytical passages that here and there occur, contain important ideas.

Valuable, however, as is Mr. Bain's work, we regard it as essentially
transitional. It presents in a digested form the results of a period of
observation; adds to these results many well-delineated facts collected
by himself; arranges new and old materials with that more scientific
method which the discipline of our times has fostered; and so prepares
the way for better generalizations. But almost of necessity its
classifications and conclusions are provisional. In the growth of each
science, not only is correct observation needful for the formation of
true theory; but true theory is needful as a preliminary to correct
observation. Of course we do not intend this assertion to be taken
literally; but as a strong expression of the fact that the two must
advance hand in hand. The first crude theory or rough classification,
based on very slight knowledge of the phenomena, is requisite as a means
of reducing the phenomena to some kind of order; and as supplying a
conception with which fresh phenomena may be compared, and their
agreement or disagreement noted. Incongruities being by and by made
manifest by wider examination of cases, there comes such modification of
the theory as brings it into a nearer correspondence with the evidence.
This reacts to the further advance of observation. More extensive and
complete observation brings additional corrections of theory; and so on
till the truth is reached. In mental science, the systematic collection
of facts having but recently commenced, it is not to be expected that
the results can be at once rightly formulated. All that may be looked
for are approximate generalizations which will presently serve for the
better directing of inquiry. Hence, even were it not now possible to say
in what way it does so, we might be tolerably certain that Mr. Bain's
work bears the stamp of the inchoate state of Psychology.

We think, however, that it will not be difficult to find in what
respects its organization is provisional; and at the same time to show
what must be the nature of a more complete organization. We propose here
to attempt this: illustrating our positions from his recently-issued
second volume.

       *       *       *       *       *

Is it possible to make a true classification without the aid of
analysis? or must there not be an analytical basis to every true
classification? Can the real relations of things be determined by the
obvious characteristics of the things? or does it not commonly happen
that certain hidden characteristics, on which the obvious ones depend,
are the truly significant ones? This is the preliminary question which a
glance at Mr. Bain's scheme of the emotions suggests.

Though not avowedly, yet by implication, Mr. Bain assumes that a right
conception of the nature, the order, and the relations of the emotions,
may be arrived at by contemplating their conspicuous objective and
subjective characters, as displayed in the adult. After pointing out
that we lack those means of classification which serve in the case of
the sensations, he says--

     "In these circumstances we must turn our attention to _the manner
     of diffusion_ of the different passions and emotions, in order to
     obtain a basis of classification analogous to the arrangement of
     the sensations. If what we have already advanced on that subject be
     at all well founded, this is the genuine turning point of the
     method to be chosen, for the same mode of diffusion will always be
     accompanied by the same mental experience, and each of the two
     aspects would identify, and would be evidence of, the other. There
     is, therefore, nothing so thoroughly characteristic of any state of
     feeling as the nature of the diffusive wave that embodies it, or
     the various organs specially roused into action by it, together
     with the manner of the action. The only drawback is our comparative
     ignorance, and our inability to discern the precise character of
     the diffusive currents in every case; a radical imperfection in the
     science of mind as constituted at present.

     "Our own consciousness, formerly reckoned the only medium of
     knowledge to the mental philosopher, must therefore be still
     referred to as a principal means of discriminating the varieties of
     human feeling. We have the power of noting agreement and difference
     among our conscious states, and on this we can raise a structure of
     classification. We recognise such generalities as pleasure, pain,
     love, anger, through the property of mental or intellectual
     discrimination that accompanies in our mind the fact of emotion. A
     certain degree of precision is attainable by this mode of mental
     comparison and analysis; the farther we can carry such precision
     the better; but that is no reason why it should stand alone to the
     neglect of the corporeal embodiments through which one mind reveals
     itself to others. The companionship of inward feeling with bodily
     manifestation is a fact of the human constitution, and deserves to
     be studied as such; and it would be difficult to find a place more
     appropriate than a treatise on the mind for setting forth the
     conjunctions and sequences traceable in this department of nature.
     I shall make no scruple in conjoining with the description of the
     mental phenomena the physical appearances, in so far as I am able
     to ascertain them.

     "There is still one other quarter to be referred to in settling a
     complete arrangement of the emotions, namely, the varieties of
     human conduct, and the machinery created in subservience to our
     common susceptibilities. For example, the vast superstructure of
     fine art has its foundations in human feeling, and in rendering an
     account of this we are led to recognise the interesting group of
     artistic or æsthetic emotions. The same outward reference to
     conduct and creations brings to light the so-called moral sense in
     man, whose foundations in the mental system have accordingly to be
     examined.

     "Combining together these various indications, or sources of
     discrimination,--outward objects, diffusive mode or expression,
     inward consciousness, resulting conduct and institutions,--I adopt
     the following arrangement of the families or natural orders of
     emotion."

Here, then, are confessedly adopted, as bases of classification, the
most manifest characters of the emotions; as discerned subjectively, and
objectively. The mode of diffusion of an emotion is one of its outside
aspects; the institutions it generates form another of its outside
aspects; and though the peculiarities of the emotion as a state of
consciousness, seem to express its intrinsic and ultimate nature, yet
such peculiarities as are perceptible by simple introspection, must also
be classed as superficial peculiarities. It is a familiar fact that
various intellectual states of consciousness turn out, when analyzed, to
have natures widely unlike those which at first appear; and we believe
the like will prove true of emotional states of consciousness. Just as
our concept of space, which is apt to be thought a simple,
undecomposable concept, is yet resolvable into experiences quite
different from that state of consciousness which we call space; so,
probably, the sentiment of affection or reverence is compounded of
elements that are severally distinct from the whole which they make up.
And much as a classification of our ideas which dealt with the idea of
space as though it were ultimate, would be a classification of ideas by
their externals; so, a classification of our emotions, which, regarding
them as simple, describes their aspects in ordinary consciousness, is a
classification of emotions by their externals.

Thus, then, Mr. Bain's grouping is throughout determined by the most
manifest attributes--those objectively displayed in the natural language
of the emotions, and in the social phenomena that result from them, and
those subjectively displayed in the aspects the emotions assume in an
analytical consciousness. And the question is--Can they be correctly
grouped after this method?

We think not; and had Mr. Bain carried farther an idea with which he has
set out, he would probably have seen that they cannot. As already said,
he avowedly adopts "the natural-history-method:" not only referring to
it in his preface, but in his first chapter giving examples of botanical
and zoological classifications, as illustrating the mode in which he
proposes to deal with the emotions. This we conceive to be a
philosophical conception; and we have only to regret that Mr. Bain has
overlooked some of its most important implications. For in what has
essentially consisted the progress of natural-history-classification? In
the abandonment of grouping by external, conspicuous characters; and in
the making of certain internal, but all-essential characters, the bases
of groups. Whales are not now ranged along with fish, because in their
general forms and habits of life they resemble fish; but they are
ranged with mammals, because the type of their organization, as
ascertained by dissection, corresponds with that of mammals. No longer
considered as sea-weeds in virtue of their forms and modes of growth,
_Polyzoa_ are now shown, by examination of their economy, to belong to
the animal kingdom. It is found, then, that the discovery of real
relationships involves analysis. It has turned out that the earlier
classifications, guided by general resemblances, though containing much
truth, and though very useful provisionally, were yet in many cases
radically wrong; and that the true affinities of organisms, and the true
homologies of their parts, are to be made out only by examining their
hidden structures. Another fact of great significance in the history of
classification is also to be noted. Very frequently the kinship of an
organism cannot be made out even by exhaustive analysis, if that
analysis is confined to the adult structure. In many cases it is needful
to examine the structure in its earlier stages; and even in its
embryonic stage. So difficult was it, for instance, to determine the
true position of the _Cirrhipedia_ among animals, by examining mature
individuals only, that Cuvier erroneously classed them with _Mollusca_,
even after dissecting them; and not until their early forms were
discovered, were they clearly proved to belong to the _Crustacea_. So
important, indeed, is the study of development as a means to
classification, that the first zoologists now hold it to be the only
absolute criterion.

Here, then, in the advance of natural-history-classification, are two
fundamental facts, which should be borne in mind when classifying the
emotions. If, as Mr. Bain rightly assumes, the emotions are to be
grouped after the natural-history-method; then it should be the
natural-history-method in its complete form, and not in its rude form.
Mr. Bain will doubtless agree in the belief, that a correct account of
the emotions in their natures and relations, must correspond with a
correct account of the nervous system--must form another side of the
same ultimate facts. Structure and function must necessarily harmonize.
Structures which have with each other certain ultimate connexions, must
have functions which have answering connexions. Structures which have
arisen in certain ways, must have functions which have arisen in
parallel ways. And hence if analysis and development are needful for the
right interpretation of structures, they must be needful for the right
interpretation of functions. Just as a scientific description of the
digestive organs must include not only their obvious forms and
connexions, but their microscopic characters, and also the ways in which
they severally result by differentiation from the primitive mucous
membrane; so must a scientific account of the nervous system include its
general arrangements, its minute structure, and its mode of evolution;
and so must a scientific account of nervous actions include the
answering three elements. Alike in classing separate organisms, and
in classing the parts of the same organism, the complete
natural-history-method involves ultimate analysis, aided by development;
and Mr. Bain, in not basing his classification of the emotions on
characters reached through these aids, has fallen short of the
conception with which he set out.

"But," it will perhaps be asked, "how are the emotions to be analyzed,
and their modes of evolution to be ascertained? Different animals, and
different organs of the same animal, may readily be compared in their
internal structures and microscopic structures, as also in their
developments; but functions, and especially such functions as the
emotions, do not admit of like comparisons."

It must be admitted that the application of these methods is here by no
means so easy. Though we can note differences and similarities between
the internal formations of two animals; it is difficult to contrast the
mental states of two animals. Though the true morphological relations of
organs may be made out by observation of embryos; yet, where such organs
are inactive before birth, we cannot completely trace the history of
their actions. Obviously, too, pursuance of inquiries of the kind
indicated, raises questions which science is not yet prepared to answer;
as, for instance--Whether all nervous functions, in common with all
other functions, arise by gradual differentiations, as their organs do?
Whether the emotions are, therefore, to be regarded as divergent modes
of action that have become unlike by successive modifications? Whether,
as two organs which originally budded out of the same membrane have not
only become different as they developed, but have also severally become
compound internally, though externally simple; so two emotions, simple
and near akin in their roots, may not only have grown unlike, but may
also have grown involved in their natures, though seeming homogeneous to
consciousness? And here, indeed, in the inability of existing science to
answer these questions which underlie a true psychological
classification, we see how purely provisional any present classification
is likely to be.

Nevertheless, even now, classification may be aided by development and
ultimate analysis to a considerable extent; and the defect in Mr. Bain's
work is, that he has not systematically availed himself of them as far
as possible. Thus we may, in the first place, study the evolution of the
emotions up through the various grades of the animal kingdom: observing
which of them are earliest and exist with the lowest organization and
intelligence; in what order the others accompany higher endowments; and
how they are severally related to the conditions of life. In the second
place, we may note the emotional differences between the lower and the
higher human races--may regard as earlier and simpler those feelings
which are common to both, and as later and more compound those which are
characteristic of the most civilized. In the third place, we may observe
the order in which the emotions unfold during the progress from infancy
to maturity. And lastly, comparing these three kinds of emotional
development, displayed in the ascending grades of the animal kingdom,
in the advance of the civilized races, and in individual history, we may
see in what respects they harmonize, and what are the implied general
truths.

Having gathered together and generalized these several classes of facts,
analysis of the emotions would be made easier. Setting out with the
assumption that every new form of emotion making its appearance in the
individual or the race, is a modification of some pre-existing emotion,
or a compound of several pre-existing emotions, we should be greatly
aided by knowing what always are the pre-existing emotions. When, for
example, we find that very few of the lower animals show any love of
accumulation, and that this feeling is absent in infancy--when we see
that an infant in arms exhibits anger, fear, wonder, while yet it
manifests no desire of permanent possession, and that a brute which has
no acquisitiveness can nevertheless feel attachment, jealousy, love of
approbation; we may suspect that the feeling which property satisfies is
compounded out of simpler and deeper feelings. We may conclude that as,
when a dog hides a bone, there must exist in him a prospective
gratification of hunger; so there must similarly at first, in all cases
where anything is secured or taken possession of, exist an ideal
excitement of the feeling which that thing will gratify. We may further
conclude that when the intelligence is such that a variety of objects
come to be utilized for different purposes--when, as among savages,
divers wants are satisfied through the articles appropriated for
weapons, shelter, clothing, ornament; the act of appropriating comes to
be one constantly involving agreeable associations, and one which is
therefore pleasurable, irrespective of the end subserved. And when, as
in civilized life, the property acquired is of a kind not conducing to
one order of gratification in particular, but is capable of
administering to all gratifications, the pleasure of acquiring property
grows more distinct from each of the various pleasures subserved--is
more completely differentiated into a separate emotion.

This illustration, roughly as it is sketched, will show what we mean by
the use of comparative psychology in aid of classification. Ascertaining
by induction the actual order of evolution of the emotions, we are led
to suspect this to be their order of successive dependence; and are so
led to recognize their order of ascending complexity; and by consequence
their true groupings.

Thus, in the very process of arranging the emotions into grades,
beginning with those involved in the lowest forms of conscious activity
and ending with those peculiar to the adult civilized man, the way is
opened for that ultimate analysis which alone can lead us to the true
science of the matter. For when we find both that there exist in a man
feelings which do not exist in a child, and that the European is
characterized by some sentiments which are wholly or in great part
absent from the savage--when we see that, besides the new emotions which
arise spontaneously as the individual becomes completely organized,
there are new emotions making their appearance in the more advanced
divisions of our race; we are led to ask--How are new emotions
generated? The lowest savages have not even the ideas of justice or
mercy: they have neither words for them nor can they be made to conceive
them; and the manifestation of them by Europeans they ascribe to fear or
cunning. There are æsthetic emotions common among ourselves, which are
scarcely in any degree experienced by some inferior races; as, for
instance, those produced by music. To which instances may be added the
less marked but more numerous contrasts that exist between civilized
races in the degrees of their several emotions. And if it is manifest,
both that all the emotions are capable of being permanently modified in
the course of successive generations, and that what must be classed as
new emotions may be brought into existence; then it follows that nothing
like a true conception of the emotions is to be obtained, until we
understand how they are evolved.

Comparative Psychology, while it raises this inquiry, prepares the way
for answering it. When observing the differences between races, we can
scarcely fail to observe also how these differences correspond with
differences between their conditions of existence, and consequent
activities. Among the lowest races of men, love of property stimulates
to the obtainment only of such things as satisfy immediate desires, or
desires of the immediate future. Improvidence is the rule: there is
little effort to meet remote contingencies. But the growth of
established societies having gradually given security of possession,
there has been an increasing tendency to provide for coming years: there
has been a constant exercise of the feeling which is satisfied by a
provision for the future; and there has been a growth of this feeling so
great that it now prompts accumulation to an extent beyond what is
needful. Note, again, that under the discipline of social life--under a
comparative abstinence from aggressive actions, and a performance of
those naturally-serviceable actions implied by the division of
labour--there has been a development of those gentle emotions of which
inferior races exhibit but the rudiments. Savages delight in giving pain
rather than pleasure--are almost devoid of sympathy; while among
ourselves, philanthropy organizes itself in laws, establishes numerous
institutions, and dictates countless private benefactions.

From which and other like facts, does it not seem an unavoidable
inference, that new emotions are developed by new experiences--new
habits of life? All are familiar with the truth that, in the individual,
each feeling may be strengthened by performing those actions which it
prompts; and to say that the feeling is _strengthened_, is to say that
it is in part _made_ by these actions. We know, further, that not
unfrequently, individuals, by persistence in special courses of conduct,
acquire special likings for such courses, disagreeable as these may be
to others; and these whims, or morbid tastes, imply incipient emotions
corresponding to these special activities. We know that emotional
characteristics, in common with all others, are hereditary; and the
differences between civilized nations descended from the same stock,
show us the cumulative results of small modifications hereditarily
transmitted. And when we see that between savage and civilized races
which diverged from one another in the remote past, and have for a
hundred generations followed modes of life becoming ever more unlike,
there exist still greater emotional contrasts; may we not infer that the
more or less distinct emotions which characterize civilized races, are
the organized results of certain daily-repeated combinations of mental
states which social life involves? Must we not say that habits not only
modify emotions in the individual, and not only beget tendencies to like
habits and accompanying emotions in descendants, but that when the
conditions of the race make the habits persistent, this progressive
modification may go on to the extent of producing emotions so far
distinct as to seem new? And if so, we may suspect that such new
emotions, and by implication all emotions analytically considered,
consist of aggregated and consolidated groups of those simpler feelings
which habitually occur together in experience. When, in the
circumstances of any race, some one kind of action or set of actions,
sensation or set of sensations, is usually followed, or accompanied, by
various other sets of actions or sensations, and so entails a large mass
of pleasurable or painful states of consciousness; these, by frequent
repetition, become so connected together that the initial action or
sensation brings the ideas of all the rest crowding into consciousness:
producing, in some degree, the pleasures or pains that have before been
felt in reality. And when this relation, besides being frequently
repeated in the individual, occurs in successive generations, all the
many nervous actions involved tend to grow organically connected. They
become incipiently reflex; and, on the occurrence of the appropriate
stimulus, the whole nervous apparatus which in past generations was
brought into activity by this stimulus, becomes nascently excited. Even
while yet there have been no individual experiences, a vague feeling of
pleasure or pain is produced; constituting what we may call the body of
the emotion. And when the experiences of past generations come to be
repeated in the individual, the emotion gains both strength and
definiteness; and is accompanied by the appropriate specific ideas.

This view of the matter, which we believe the established truths of
Physiology and Psychology unite in indicating, and which is the view
that generalizes the phenomena of habit, of national characteristics, of
civilization in its moral aspects, at the same time that it gives us a
conception of emotion in its origin and ultimate nature, may be
illustrated from the mental modifications undergone by animals. On
newly-discovered lands not inhabited by man, birds are so devoid of fear
as to allow themselves to be knocked over with sticks; but in the course
of generations, they acquire such a dread of man as to fly on his
approach; and this dread is manifested by young as well as by old. Now
unless this change be ascribed to the killing-off of the less fearful,
and the preservation and multiplication of the more fearful, which,
considering the comparatively small number killed by man, is an
inadequate cause; it must be ascribed to accumulated experiences; and
each experience must be held to have a share in producing it. We must
conclude that in each bird which escapes with injuries inflicted by man,
or is alarmed by the outcries of other members of the flock (gregarious
creatures of any intelligence being necessarily more or less
sympathetic), there is established an association of ideas between the
human aspect and the pains, direct and indirect, suffered from human
agency. And we must further conclude that the state of consciousness
which impels the bird to take flight, is at first nothing more than an
ideal reproduction of those painful impressions which before followed
man's approach; that such ideal reproduction becomes more vivid and more
massive as the painful experiences, direct or sympathetic, increase; and
that thus the emotion in its incipient state, is nothing else than an
aggregation of the revived pains before experienced. As, in the course
of generations, the young birds of this race begin to display a fear of
man before yet they have been injured by him, it is an unavoidable
inference that the nervous system of the race has been organically
modified by these experiences: we have no choice but to conclude that
when a young bird is thus led to fly, it is because the impression
produced on its senses by the approaching man, entails, through an
incipiently-reflex action, a partial excitement of all those nerves
which in its ancestors had been excited under the like conditions; that
this partial excitement has its accompanying painful consciousness; and
that the vague painful consciousness thus arising, constitutes emotion
proper--_emotion undecomposable into specific experiences, and therefore
seemingly homogeneous_.

If such be the explanation of the fact in this case, then it is in all
cases. If emotion is so generated here, then it is so generated
throughout. We must perforce conclude that the emotional modifications
displayed by different nations, and those higher emotions by which
civilized are distinguished from savage, are to be accounted for on the
same principle. And concluding this, we are led strongly to suspect that
the emotions in general have severally thus originated.

Perhaps we have now made sufficiently clear what we mean by the study of
the emotions through analysis and development. We have aimed to justify
the positions that, without analysis aided by development, there cannot
be a true natural history of the emotions; and that a natural history of
the emotions based on external characters can be but provisional. We
think that Mr. Bain, in confining himself to an account of the emotions
as they exist in the adult civilized man, has neglected those classes of
facts out of which the science of the matter must chiefly be built. It
is true that he has treated of habits as modifying emotions in the
individual; but he has not recognized the fact that where conditions
render habits persistent in successive generations, such modifications
are cumulative: he has not hinted that the modifications produced by
habit are emotions in the making. It is true, also, that he occasionally
refers to the characteristics of children; but he does not
systematically trace the changes through which childhood passes into
manhood, as throwing light on the order and genesis of the emotions. It
is further true that he here and there refers to national traits in
illustration of his subject; but these stand as isolated facts, having
no general significance: there is no hint of any relation between them
and the national circumstances; while all those many moral contrasts
between lower and higher races which throw great light on
classification, are passed over. And once more, it is true that many
passages of his work, and sometimes, indeed, whole sections of it, are
analytical; but his analyses are incidental--they do not underlie his
entire scheme, but are here and there added to it. In brief, he has
written a Descriptive Psychology, which does not appeal to Comparative
Psychology and Analytical Psychology for its leading ideas. And in doing
this, he has omitted much that should be included in a natural history
of the mind; while to that part of the subject with which he has dealt,
he has given a necessarily-imperfect organization.

       *       *       *       *       *

Even leaving out of view the absence of those methods and criteria on
which we have been insisting, it appears to us that meritorious as is
Mr. Bain's book in its details, it is defective in some of its leading
ideas. The first paragraphs of his first chapter, quite startled us by
the strangeness of their definitions--a strangeness which can scarcely
be ascribed to laxity of expression. The paragraphs run thus:--

     "Mind is comprised under three heads,--Emotion, Volition, and
     Intellect.

     "EMOTION is the name here used to comprehend all that is understood
     by feelings, states of feeling, pleasures, pains, passions,
     sentiments, affections. Consciousness, and conscious states also
     for the most part denote modes of emotion, although there is such a
     thing as the Intellectual consciousness.

     "VOLITION, on the other hand, indicates the great fact that our
     Pleasures and Pains, which are not the whole of our emotions,
     prompt to action, or stimulate the active machinery of the living
     framework to perform such operations as procure the first and abate
     the last. To withdraw from a scalding heat, and cling to a gentle
     warmth, are exercises of volition."

The last of these definitions, which we may most conveniently take
first, seems to us very faulty. We cannot but feel astonished that Mr.
Bain, familiar as he is with the phenomena of reflex action, should have
so expressed himself as to include a great part of them along with the
phenomena of volition. He seems to be ignoring the discriminations of
modern science, and returning to the vague conceptions of the past--nay
more, he is comprehending under volition what even the popular speech
would hardly bring under it. If you were to blame any one for snatching
his foot from the scalding water into which he had inadvertently put it,
he would tell you that he could not help it; and his reply would be
indorsed by the general experience, that the withdrawal of a limb from
contact with something extremely hot, is quite involuntary--that it
takes place not only without volition, but in defiance of an effort of
will to maintain the contact. How, then, can that be instanced as an
example of volition, which occurs even when volition is antagonistic? We
are quite aware that it is impossible to draw any absolute line of
demarcation between automatic actions and actions which are not
automatic. Doubtless we may pass gradually from the purely reflex,
through the consensual, to the voluntary. Taking the case Mr. Bain
cites, it is manifest that from a heat of such moderate degree that the
withdrawal from it is wholly voluntary, we may advance by infinitesimal
steps to a heat which compels involuntary withdrawal; and that there is
a stage at which the voluntary and involuntary actions are mixed. But
the difficulty of absolute discrimination is no reason for neglecting
the broad general contrast; any more than it is for confounding light
with darkness. If we are to include as examples of volition, all cases
in which pleasures and pains "stimulate the active machinery of the
living framework to perform such operations as procure the first and
abate the last," then we must consider sneezing and coughing as examples
of volition; and Mr. Bain surely cannot mean this. Indeed, we must
confess ourselves at a loss. On the one hand if he does not mean it, his
expression is lax to a degree that surprises us in so careful a writer.
On the other hand, if he does mean it, we cannot understand his point of
view.

A parallel criticism applies to his definition of Emotion. Here, too, he
has departed from the ordinary acceptation of the word; and, as we
think, in the wrong direction. Whatever may be the interpretation that
is justified by its derivation, the word emotion has come generally to
mean that kind of feeling which is not a direct result of any action on
the organism; but is either an indirect result of such action, or arises
quite apart from such action. It is used to indicate those sentient
states which are independently generated in consciousness; as
distinguished from those generated in our corporeal framework, and known
as sensations. Now this distinction, tacitly made in common speech, is
one which Psychology cannot well reject; but one which it must adopt,
and to which it must give scientific precision. Mr. Bain, however,
appears to ignore any such distinction. Under the term emotion, he
includes not only passions, sentiments, affections, but all "feelings,
states of feeling, pleasures, pains,"--that is, all sensations. This
does not appear to be a mere lapse of expression; for when, in the
opening sentence, he asserts that "mind is comprised under the three
heads--Emotion, Volition, and Intellect," he of necessity implies that
sensation is included under one of these heads; and as it cannot be
included under volition or intellect, it must be classed with emotion;
as it clearly is in the next sentence.

We cannot but think this a retrograde step. Though distinctions which
have been established in popular thought and language, are not
unfrequently merged in the higher generalizations of science (as, for
instance, when crabs and worms are grouped together in the sub-kingdom
_Annulosa_); yet science very generally recognizes the validity of these
distinctions, as real though not fundamental. And so in the present
case. Such community as analysis discloses between sensation and
emotion, must not shut out the broad contrast that exists between them.
If there needs a wider word, as there does, to signify any sentient
state whatever; then we may fitly adopt for this purpose the word
currently so used, namely, "Feeling." And considering as Feelings all
that great division of mental states which we do not class as
Cognitions, we may then separate this great division into the two
orders, Sensations and Emotions.

       *       *       *       *       *

And here we may, before concluding, briefly indicate the leading
outlines of a classification which reduces this distinction to a
scientific form, and develops it somewhat further--a classification
which, while suggested by certain fundamental traits reached without a
very lengthened inquiry, is yet, we believe, in harmony with that
disclosed by detailed analysis.

Leaving out of view the Will, which is a simple homogeneous mental
state, forming the link between feeling and action, and not admitting of
subdivisions; our states of consciousness fall into two great
classes--COGNITIONS and FEELINGS.

COGNITIONS, or those modes of mind in which we are occupied with the
_relations_ that subsist among our feelings, are divisible into four
great sub-classes.

_Presentative cognitions_; or those in which consciousness is occupied
in localizing a sensation impressed on the organism--occupied, that is,
with the relation between this presented mental state and those other
presented mental states which make up our consciousness of the part
affected: as when we cut ourselves.

_Presentative-representative cognitions_; or those in which
consciousness is occupied with the relation between a sensation or group
of sensations and the representations of those various other sensations
that accompany it in experience. This is what we commonly call
perception--an act in which, along with certain impressions presented to
consciousness, there arise in consciousness the ideas of certain other
impressions ordinarily connected with the presented ones: as when its
visible form and colour, lead us to mentally endow an orange with all
its other attributes.

_Representative cognitions_; or those in which consciousness is occupied
with the relations among ideas or represented sensations; as in all acts
of recollection.

_Re-representative cognitions_; or those in which the occupation of
consciousness is not by representation of special relations that have
before been presented to consciousness; but those in which such
represented special relations are thought of merely as comprehended in a
general relation--those in which the concrete relations once
experienced, in so far as they become objects of consciousness at all,
are incidentally represented, along with the abstract relation which
formulates them. The ideas resulting from this abstraction, do not
themselves represent actual experiences; but are symbols which stand for
groups of such actual experiences--represent aggregates of
representations. And thus they may be called re-representative
cognitions. It is clear that the process of re-representation is
carried to higher stages, as the thought becomes more abstract.

FEELINGS, or those modes of mind in which we are occupied, not with the
relations subsisting between our sentient states, but with the sentient
states themselves, are divisible into four parallel sub-classes.

_Presentative feelings_, ordinarily called sensations, are those mental
states in which, instead of regarding a corporeal impression as of this
or that kind, or as located here or there, we contemplate it in itself
as pleasure or pain: as when eating.

_Presentative-representative feelings_, embracing a great part of what
we commonly call emotions, are those in which a sensation, or group of
sensations, or group of sensations and ideas, arouses a vast aggregation
of represented sensations; partly of individual experience, but chiefly
deeper than individual experience, and, consequently, indefinite. The
emotion of terror may serve as an example. Along with certain
impressions made on the eyes or ears, or both, are recalled in
consciousness many of the pains to which such impressions have before
been the antecedents; and when the relation between such impressions and
such pains has been habitual in the race, the definite ideas of such
pains which individual experience has given, are accompanied by
the indefinite pains that result from inherited effects of
experiences--vague feelings which we may call organic representations.
In an infant, crying at a strange sight or sound while yet in the
nurse's arms, we see these organic representations called into existence
in the shape of dim discomfort, to which individual experience has yet
given no specific outlines.

_Representative feelings_, comprehending the ideas of the feelings above
classed, when they are called up apart from the appropriate external
excitements. As instances of these may be named the feelings with which
the descriptive poet writes, and which are aroused in the minds of his
readers.

_Re-representative feelings_, under which head are included those more
complex sentient states that are less the direct results of external
excitements than the indirect or reflex results of them. The love of
property is a feeling of this kind. It is awakened not by the presence
of any special object, but by ownable objects at large; and it is not
from the mere presence of such object, but from a certain ideal relation
to them, that it arises. As before shown (p. 253) it consists, not of
the represented advantages of possessing this or that, but of the
represented advantages of possession in general--is not made up of
certain concrete representations, but of the abstracts of many concrete
representations; and so is re-representative. The higher sentiments, as
that of justice, are still more completely of this nature. Here the
sentient state is compounded out of sentient states that are themselves
wholly, or almost wholly, re-representative: it involves representations
of those lower emotions which are produced by the possession of
property, by freedom of action, etc.; and thus is re-representative in a
higher degree.

This classification, here roughly indicated and capable of further
expansion, will be found in harmony with the results of detailed
analysis aided by development. Whether we trace mental progression
through the grades of the animal kingdom, through the grades of mankind,
or through the stages of individual growth; it is obvious that the
advance, alike in cognitions and feelings, is, and must be, from the
presentative to the more and more remotely representative. It is
undeniable that intelligence ascends from those simple perceptions in
which consciousness is occupied in localizing and classifying
sensations, to perceptions more and more compound, to simple reasoning,
to reasoning more and more complex and abstract--more and more remote
from sensation. And in the evolution of feelings, there is a parallel
series of steps. Simple sensations; sensations combined together;
sensations combined with represented sensations; represented sensations
organized into groups, in which their separate characters are very much
merged; representations of these representative groups, in which the
original components have become still more vague. In both cases, the
progress has necessarily been from the simple and concrete to the
complex and abstract; and as with the cognitions, so with the feelings,
this must be the basis of classification.

The space here occupied with criticisms on Mr. Bain's work, we might
have filled with exposition and eulogy, had we thought this the more
important. Though we have freely pointed out what we conceive to be its
defects, let it not be inferred that we question its great merits. We
repeat that, as a natural history of the mind, we believe it to be
the best yet produced. It is a most valuable collection of
carefully-elaborated materials. Perhaps we cannot better express our
sense of its worth, than by saying that, to those who hereafter give to
this branch of Psychology a thoroughly scientific organization, Mr.
Bain's book will be indispensable.




THE SOCIAL ORGANISM.

    [_First published in_ The Westminster Review _for January,_ 1860.]


Sir James Macintosh got great credit for the saying, that "constitutions
are not made, but grow." In our day, the most significant thing about
this saying is, that it was ever thought so significant. As from the
surprise displayed by a man at some familiar fact, you may judge of his
general culture; so from the admiration which an age accords to a new
thought, its average degree of enlightenment may be inferred. That this
apophthegm of Macintosh should have been quoted and requoted as it has,
shows how profound has been the ignorance of social science. A small ray
of truth has seemed brilliant, as a distant rushlight looks like a star
in the surrounding darkness.

Such a conception could not, indeed, fail to be startling when let fall
in the midst of a system of thought to which it was utterly alien.
Universally in Macintosh's day, things were explained on the hypothesis
of manufacture, rather than that of growth; as indeed they are, by the
majority, in our own day. It was held that the planets were severally
projected round the Sun from the Creator's hand, with just the velocity
required to balance the Sun's attraction. The formation of the Earth,
the separation of sea from land, the production of animals, were
mechanical works from which God rested as a labourer rests. Man was
supposed to be moulded after a manner somewhat akin to that in which a
modeller makes a clay-figure. And of course, in harmony with such
ideas, societies were tacitly assumed to be arranged thus or thus by
direct interposition of Providence; or by the regulations of law-makers;
or by both.

Yet that societies are not artificially put together, is a truth so
manifest, that it seems wonderful men should ever have overlooked it.
Perhaps nothing more clearly shows the small value of historical
studies, as they have been commonly pursued. You need but to look at the
changes going on around, or observe social organization in its leading
traits, to see that these are neither supernatural, nor are determined
by the wills of individual men, as by implication the older historians
teach; but are consequent on general natural causes. The one case of the
division of labour suffices to prove this. It has not been by command of
any ruler that some men have become manufacturers, while others have
remained cultivators of the soil. In Lancashire, millions have devoted
themselves to the making of cotton-fabrics; in Yorkshire, another
million lives by producing woollens; and the pottery of Staffordshire,
the cutlery of Sheffield, the hardware of Birmingham, severally occupy
their hundreds of thousands. These are large facts in the structure of
English society; but we can ascribe them neither to miracle, nor to
legislation. It is not by "the hero as king," any more than by
"collective wisdom," that men have been segregated into producers,
wholesale distributors, and retail distributors. Our industrial
organization, from its main outlines down to its minutest details, has
become what it is, not simply without legislative guidance, but, to a
considerable extent, in spite of legislative hindrances. It has arisen
under the pressure of human wants and resulting activities. While each
citizen has been pursuing his individual welfare, and none taking
thought about division of labour, or conscious of the need of it,
division of labour has yet been ever becoming more complete. It has been
doing this slowly and silently: few having observed it until quite
modern times. By steps so small, that year after year the industrial
arrangements have seemed just what they were before--by changes as
insensible as those through which a seed passes into a tree; society has
become the complex body of mutually-dependent workers which we now see.
And this economic organization, mark, is the all-essential organization.
Through the combination thus spontaneously evolved, every citizen is
supplied with daily necessaries; while he yields some product or aid to
others. That we are severally alive to-day, we owe to the regular
working of this combination during the past week; and could it be
suddenly abolished, multitudes would be dead before another week ended.
If these most conspicuous and vital arrangements of our social structure
have arisen not by the devising of any one, but through the individual
efforts of citizens to satisfy their own wants; we may be tolerably
certain that the less important arrangements have similarly arisen.

"But surely," it will be said, "the social changes directly produced by
law, cannot be classed as spontaneous growths. When parliaments or kings
order this or that thing to be done, and appoint officials to do it, the
process is clearly artificial; and society to this extent becomes a
manufacture rather than a growth." No, not even these changes are
exceptions, if they be real and permanent changes. The true sources of
such changes lie deeper than the acts of legislators. To take first the
simplest instance. We all know that the enactments of representative
governments ultimately depend on the national will: they may for a time
be out of harmony with it, but eventually they must conform to it. And
to say that the national will finally determines them, is to say that
they result from the average of individual desires; or, in other
words--from the average of individual natures. A law so initiated,
therefore, really grows out of the popular character. In the case of a
Government representing a dominant class, the same thing holds, though
not so manifestly. For the very existence of a class monopolizing all
power, is due to certain sentiments in the commonalty. Without the
feeling of loyalty on the part of retainers, a feudal system could not
exist. We see in the protest of the Highlanders against the abolition of
heritable jurisdictions, that they preferred that kind of local rule.
And if to the popular nature must be ascribed the growth of an
irresponsible ruling class; then to the popular nature must be ascribed
the social arrangements which that class creates in the pursuit of its
own ends. Even where the Government is despotic, the doctrine still
holds. The character of the people is, as before, the original source of
this political form; and, as we have abundant proof, other forms
suddenly created will not act, but rapidly retrograde to the old form.
Moreover, such regulations as a despot makes, if really operative, are
so because of their fitness to the social state. His acts being very
much swayed by general opinion--by precedent, by the feeling of his
nobles, his priesthood, his army--are in part immediate results of the
national character; and when they are out of harmony with the national
character, they are soon practically abrogated. The failure of Cromwell
permanently to establish a new social condition, and the rapid revival
of suppressed institutions and practices after his death, show how
powerless is a monarch to change the type of the society he governs. He
may disturb, he may retard, or he may aid the natural process of
organization; but the general course of this process is beyond his
control. Nay, more than this is true. Those who regard the histories of
societies as the histories of their great men, and think that these
great men shape the fates of their societies, overlook the truth that
such great men are the products of their societies. Without certain
antecedents--without a certain average national character, they neither
could have been generated nor could have had the culture which formed
them. If their society is to some extent re-moulded by them, they
were, both before and after birth, moulded by their society--were the
results of all those influences which fostered the ancestral character
they inherited, and gave their own early bias, their creed, morals,
knowledge, aspirations. So that such social changes as are immediately
traceable to individuals of unusual power, are still remotely traceable
to the social causes which produced these individuals; and hence, from
the highest point of view, such social changes also, are parts of the
general developmental process.

Thus that which is so obviously true of the industrial structure of
society, is true of its whole structure. The fact that "constitutions
are not made, but grow," is simply a fragment of the much larger fact,
that under all its aspects and through all its ramifications, society is
a growth and not a manufacture.

       *       *       *       *       *

A perception that there exists some analogy between the body politic and
a living individual body, was early reached; and has from time to time
re-appeared in literature. But this perception was necessarily vague and
more or less fanciful. In the absence of physiological science, and
especially of those comprehensive generalizations which it has but
lately reached, it was impossible to discern the real parallelisms.

The central idea of Plato's model Republic, is the correspondence
between the parts of a society and the faculties of the human mind.
Classifying these faculties under the heads of Reason, Will, and
Passion, he classifies the members of his ideal society under what he
regards as three analogous heads:--councillors, who are to exercise
government; military or executive, who are to fulfil their behests; and
the commonalty, bent on gain and selfish gratification. In other words,
the ruler, the warrior, and the craftsman, are, according to him, the
analogues of our reflective, volitional, and emotional powers. Now
even were there truth in the implied assumption of a parallelism
between the structure of a society and that of a man, this
classification would be indefensible. It might more truly be contended
that, as the military power obeys the commands of the Government, it is
the Government which answers to the Will; while the military power is
simply an agency set in motion by it. Or, again, it might be contended
that whereas the Will is a product of predominant desires, to which the
Reason serves merely as an eye, it is the craftsmen, who, according to
the alleged analogy, ought to be the moving power of the warriors.

Hobbes sought to establish a still more definite parallelism: not,
however, between a society and the human mind, but between a society and
the human body. In the introduction to the work in which he develops
this conception, he says--

     "For by art is created that great LEVIATHAN called a COMMONWEALTH,
     or STATE, in Latin CIVITAS, which is but an artificial man; though
     of greater stature and strength than the natural, for whose
     protection and defence it was intended, and in which the
     _sovereignty_ is an artificial _soul_, as giving life and motion to
     the whole body; the _magistrates_ and other _officers_ of
     judicature and execution, artificial _joints_; _reward_ and
     _punishment_, by which, fastened to the seat of the sovereignty,
     every joint and member is moved to perform his duty, are the
     _nerves_, that do the same in the body natural; the _wealth_ and
     _riches_ of all the particular members are the _strength_; _salus
     populi_, the _people's safety_, its _business_; _counsellors_, by
     whom all things needful for it to know are suggested unto it, are
     the _memory_; _equity_ and _laws_ an artificial _reason_ and
     _will_; _concord_, _health_; _sedition_, _sickness_; and _civil
     war_, _death_."

And Hobbes carries this comparison so far as actually to give a drawing
of the Leviathan--a vast human-shaped figure, whose body and limbs are
made up of multitudes of men. Just noting that these different analogies
asserted by Plato and Hobbes, serve to cancel each other (being, as they
are, so completely at variance), we may say that on the whole those of
Hobbes are the more plausible. But they are full of inconsistencies. If
the sovereignty is the _soul_ of the body-politic, how can it be that
magistrates, who are a kind of deputy-sovereigns, should be comparable
to _joints_? Or, again, how can the three mental functions, memory,
reason, and will, be severally analogous, the first to counsellors, who
are a class of public officers, and the other two to equity and laws,
which are not classes of officers, but abstractions? Or, once more, if
magistrates are the artificial joints of society, how can reward and
punishment be its nerves? Its nerves must surely be some class of
persons. Reward and punishment must in societies, as in individuals, be
_conditions_ of the nerves, and not the nerves themselves.

But the chief errors of these comparisons made by Plato and Hobbes, lie
much deeper. Both thinkers assume that the organization of a society is
comparable, not simply to the organization of a living body in general,
but to the organization of the human body in particular. There is no
warrant whatever for assuming this. It is in no way implied by the
evidence; and is simply one of those fancies which we commonly find
mixed up with the truths of early speculation. Still more erroneous are
the two conceptions in this, that they construe a society as an
artificial structure. Plato's model republic--his ideal of a healthful
body-politic--is to be consciously put together by men, just as a watch
might be; and Plato manifestly thinks of societies in general as thus
originated. Quite specifically does Hobbes express a like view. "For by
_art_," he says, "is created that great LEVIATHAN called a
COMMONWEALTH." And he even goes so far as to compare the supposed social
contract, from which a society suddenly originates, to the creation of a
man by the divine fiat. Thus they both fall into the extreme
inconsistency of considering a community as similar in structure to a
human being, and yet as produced in the same way as an artificial
mechanism--in nature, an organism; in history, a machine.

Notwithstanding errors, however, these speculations have considerable
significance. That such likenesses, crudely as they are thought out,
should have been alleged by Plato and Hobbes and others, is a reason
for suspecting that _some_ analogy exists. The untenableness of the
particular parallelisms above instanced, is no ground for denying an
essential parallelism; since early ideas are usually but vague
adumbrations of the truth. Lacking the great generalizations of biology,
it was, as we have said, impossible to trace out the real relations of
social organizations to organizations of another order. We propose here
to show what are the analogies which modern science discloses.

       *       *       *       *       *

Let us set out by succinctly stating the points of similarity and the
points of difference. Societies agree with individual organisms in four
conspicuous peculiarities:--

1. That commencing as small aggregations, they insensibly augment in
mass: some of them eventually reaching ten thousand times what they
originally were.

2. That while at first so simple in structure as to be considered
structureless, they assume, in the course of their growth, a
continually-increasing complexity of structure.

3. That though in their early, undeveloped states, there exists in them
scarcely any mutual dependence of parts, their parts gradually acquire a
mutual dependence; which becomes at last so great, that the activity and
life of each part is made possible only by the activity and life of the
rest.

4. That the life of a society is independent of, and far more prolonged
than, the lives of any of its component units; who are severally born,
grow, work, reproduce, and die, while the body-politic composed of them
survives generation after generation, increasing in mass, in
completeness of structure, and in functional activity.

These four parallelisms will appear the more significant the more we
contemplate them. While the points specified, are points in which
societies agree with individual organisms, they are also points in which
individual organisms agree with one another, and disagree with all
things else. In the course of its existence, every plant and animal
increases in mass, in a way not paralleled by inorganic objects: even
such inorganic objects as crystals, which arise by growth, show us no
such definite relation between growth and existence as organisms do. The
orderly progress from simplicity to complexity, displayed by
bodies-politic in common with living bodies, is a characteristic which
distinguishes living bodies from the inanimate bodies amid which they
move. That functional dependence of parts, which is scarcely more
manifest in animals than in nations, has no counterpart elsewhere. And
in no aggregate except an organic or a social one, is there a perpetual
removal and replacement of parts, joined with a continued integrity of
the whole. Moreover, societies and organisms are not only alike in these
peculiarities, in which they are unlike all other things; but the
highest societies, like the highest organisms, exhibit them in the
greatest degree. We see that the lowest animals do not increase to
anything like the sizes of the higher ones; and, similarly, we see that
aboriginal societies are comparatively limited in their growths. In
complexity, our large civilized nations as much exceed primitive savage
tribes, as a mammal does a zoophyte. Simple communities, like simple
creatures, have so little mutual dependence of parts, that mutilation or
subdivision causes but little inconvenience; but from complex
communities, as from complex creatures, you cannot remove any
considerable organ without producing great disturbance or death of the
rest. And in societies of low type, as in inferior animals, the life of
the aggregate, often cut short by division or dissolution, exceeds in
length the lives of the component units, very far less than in civilized
communities and superior animals; which outlive many generations of
their component units.

On the other hand, the leading differences between societies and
individual organisms are these:--

1. That societies have no specific external forms. This, however, is a
point of contrast which loses much of its importance, when we remember
that throughout the vegetal kingdom, as well as in some lower divisions
of the animal kingdom, the forms are often very indefinite--definiteness
being rather the exception than the rule; and that they are manifestly
in part determined by surrounding physical circumstances, as the forms
of societies are. If, too, it should eventually be shown, as we believe
it will, that the form of every species of organism has resulted from
the average play of the external forces to which it has been subject
during its evolution as a species; then, that the external forms of
societies should depend, as they do, on surrounding conditions, will be
a further point of community.

2. That though the living tissue whereof an individual organism
consists, forms a continuous mass, the living elements of a society do
not form a continuous mass; but are more or less widely dispersed over
some portion of the Earth's surface. This, which at first sight appears
to be an absolute distinction, is one which yet to a great extent fades
when we contemplate all the facts. For, in the lower divisions of the
animal and vegetal kingdoms, there are types of organization much more
nearly allied, in this respect, to the organization of a society, than
might be supposed--types in which the living units essentially composing
the mass, are dispersed through an inert substance, that can scarcely be
called living in the full sense of the word. It is thus with some of the
_Protococci_ and with the _Nostoceæ_, which exist as cells imbedded in a
viscid matter. It is so, too, with the _Thalassicollæ_--bodies made up
of differentiated parts, dispersed through an undifferentiated jelly.
And throughout considerable portions of their bodies, some of the
_Acalephæ_ exhibit more or less this type of structure. Now this is very
much the case with a society. For we must remember that though the men
who make up a society are physically separate, and even scattered, yet
the surface over which they are scattered is not one devoid of life, but
is covered by life of a lower order which ministers to their life. The
vegetation which clothes a country makes possible the animal life in
that country; and only through its animal and vegetal products can such
a country support a society. Hence the members of the body-politic are
not to be regarded as separated by intervals of dead space, but as
diffused through a space occupied by life of a lower order. In our
conception of a social organism, we must include all that lower organic
existence on which human existence, and therefore social existence,
depend. And when we do this, we see that the citizens who make up a
community may be considered as highly vitalized units surrounded by
substances of lower vitality, from which they draw their nutriment: much
as in the cases above instanced.

3. The third difference is that while the ultimate living elements of an
individual organism are mostly fixed in their relative positions, those
of the social organism are capable of moving from place to place. But
here, too, the disagreement is much less than would be supposed. For
while citizens are locomotive in their private capacities, they are
fixed in their public capacities. As farmers, manufacturers, or traders,
men carry on their businesses at the same spots, often throughout their
whole lives; and if they go away occasionally, they leave behind others
to discharge their functions in their absence. Each great centre of
production, each manufacturing town or district, continues always in the
same place; and many of the firms in such town or district, are for
generations carried on either by the descendants or successors of those
who founded them. Just as in a living body, the cells that make up some
important organ severally perform their functions for a time and then
disappear, leaving others to supply their places; so, in each part of a
society the organ remains, though the persons who compose it change.
Thus, in social life, as in the life of an animal, the units as well as
the larger agencies formed of them, are in the main stationary as
respects the places where they discharge their duties and obtain their
sustenance. And hence the power of individual locomotion does not
practically affect the analogy.

4. The last and perhaps the most important distinction is, that while in
the body of an animal only a special tissue is endowed with feeling, in
a society all the members are endowed with feeling. Even this
distinction, however, is not a complete one. For in some of the lowest
animals, characterized by the absence of a nervous system, such
sensitiveness as exists is possessed by all parts. It is only in the
more organized forms that feeling is monopolized by one class of the
vital elements. And we must remember that societies, too, are not
without a certain differentiation of this kind. Though the units of a
community are all sensitive, they are so in unequal degrees. The classes
engaged in laborious occupations are less susceptible, intellectually
and emotionally, than the rest; and especially less so than the classes
of highest mental culture. Still, we have here a tolerably decided
contrast between bodies-politic and individual bodies; and it is one
which we should keep constantly in view. For it reminds us that while,
in individual bodies, the welfare of all other parts is rightly
subservient to the welfare of the nervous system, whose pleasurable or
painful activities make up the good or ill of life; in bodies-politic
the same thing does not hold, or holds to but a very slight extent. It
is well that the lives of all parts of an animal should be merged in the
life of the whole, because the whole has a corporate consciousness
capable of happiness or misery. But it is not so with a society; since
its living units do not and cannot lose individual consciousness, and
since the community as a whole has no corporate consciousness. This is
an everlasting reason why the welfares of citizens cannot rightly be
sacrificed to some supposed benefit of the State, and why, on the other
hand, the State is to be maintained solely for the benefit of
citizens. The corporate life must here be subservient to the lives of
the parts, instead of the lives of the parts being subservient to the
corporate life.

Such, then, are the points of analogy and the points of difference. May
we not say that the points of difference serve but to bring into clearer
light the points of analogy? While comparison makes definite the obvious
contrasts between organisms commonly so called, and the social organism,
it shows that even these contrasts are not so decided as was to be
expected. The indefiniteness of form, the discontinuity of the parts,
and the universal sensitiveness, are not only peculiarities of the
social organism which have to be stated with considerable
qualifications; but they are peculiarities to which the inferior classes
of animals present approximations. Thus we find but little to conflict
with the all-important analogies. Societies slowly augment in mass; they
progress in complexity of structure; at the same time their parts become
more mutually dependent; their living units are removed and replaced
without destroying their integrity; and the extents to which they
display these peculiarities are proportionate to their vital activities.
These are traits that societies have in common with organic bodies. And
these traits in which they agree with organic bodies and disagree with
all other things, entirely subordinate the minor distinctions: such
distinctions being scarcely greater than those which separate one half
of the organic kingdom from the other. The _principles_ of organization
are the same, and the differences are simply differences of application.

Here ending this general survey of the facts which justify the
comparison of a society with a living body, let us look at them in
detail. We shall find that the parallelism becomes the more marked the
more closely it is examined.

       *       *       *       *       *

The lowest animal and vegetal forms--_Protozoa_ and _Protophyta_--are
chiefly inhabitants of the water. They are minute bodies, most of which
are made individually visible only by the microscope. All of them are
extremely simple in structure, and some of them, as the _Rhizopods_,
almost structureless. Multiplying, as they ordinarily do, by the
spontaneous division of their bodies, they produce halves which may
either become quite separate and move away in different directions, or
may continue attached. By the repetition of this process of fission,
aggregations of various sizes and kinds are formed. Among the
_Protophyta_ we have some classes, as the _Diatomaceæ_ and the
Yeast-plant, in which the individuals may be either separate or attached
in groups of two, three, four, or more; other classes in which a
considerable number of cells are united into a thread (_Conferva_,
_Monilia_); others in which they form a network (_Hydrodictyon_); others
in which they form plates (_Ulva_); and others in which they form masses
(_Laminaria_, _Agaricus_): all which vegetal forms, having no
distinction of root, stem, or leaf, are called _Thallogens_. Among the
_Protozoa_ we find parallel facts. Immense numbers of _Amoeba_-like
creatures, massed together in a framework of horny fibres, constitute
Sponge. In the _Foraminifera_ we see smaller groups of such creatures
arranged into more definite shapes. Not only do these almost
structureless _Protozoa_ unite into regular or irregular aggregations of
various sizes, but among some of the more organized ones, as the
_Vorticellæ_, there are also produced clusters of individuals united to
a common stem. But these little societies of monads, or cells, or
whatever else we may call them, are societies only in the lowest sense:
there is no subordination of parts among them--no organization. Each of
the component units lives by and for itself; neither giving nor
receiving aid. The only mutual dependence is that consequent on
mechanical union.

Do we not here discern analogies to the first stages of human societies?
Among the lowest races, as the Bushmen, we find but incipient
aggregation: sometimes single families, sometimes two or three families
wandering about together. The number of associated units is small and
variable, and their union inconstant. No division of labour exists
except between the sexes, and the only kind of mutual aid is that of
joint attack or defence. We see an undifferentiated group of
individuals, forming the germ of a society; just as in the homogeneous
groups of cells above described, we see the initial stage of animal and
vegetal organization.

The comparison may now be carried a step higher. In the vegetal kingdom
we pass from the _Thallogens_, consisting of mere masses of similar
cells, to the _Acrogens_, in which the cells are not similar throughout
the whole mass; but are here aggregated into a structure serving as leaf
and there into a structure serving as root; thus forming a whole in
which there is a certain subdivision of functions among the units, and
therefore a certain mutual dependence. In the animal kingdom we find
analogous progress. From mere unorganized groups of cells, or cell-like
bodies, we ascend to groups of such cells arranged into parts that have
different duties. The common Polype, from the substance of which may be
separated cells that exhibit, when detached, appearances and movements
like those of a solitary _Amoeba_, illustrates this stage. The
component units, though still showing great community of character,
assume somewhat diverse functions in the skin, in the internal surface,
and in the tentacles. There is a certain amount of "physiological
division of labour."

Turning to societies, we find these stages paralleled in most aboriginal
tribes. When, instead of such small variable groups as are formed by
Bushmen, we come to the larger and more permanent groups formed by
savages not quite so low, we find traces of social structure. Though
industrial organization scarcely shows itself, except in the different
occupations of the sexes; yet there is more or less of governmental
organization. While all the men are warriors and hunters, only a part
of them are included in the council of chiefs; and in this council of
chiefs some one has commonly supreme authority. There is thus a certain
distinction of classes and powers; and through this slight
specialization of functions is effected a rude co-operation among the
increasing mass of individuals, whenever the society has to act in its
corporate capacity. Beyond this analogy in the slight extent to which
organization is carried, there is analogy in the indefiniteness of the
organization. In the _Hydra_, the respective parts of the creature's
substance have many functions in common. They are all contractile;
omitting the tentacles, the whole of the external surface can give
origin to young _hydræ_; and, when turned inside out, stomach performs
the duties of skin and skin the duties of stomach. In aboriginal
societies such differentiations as exist are similarly imperfect.
Notwithstanding distinctions of rank, all persons maintain themselves by
their own exertions. Not only do the head men of the tribe, in common
with the rest, build their own huts, make their own weapons, kill their
own food; but the chief does the like. Moreover, such governmental
organization as exists is inconstant. It is frequently changed by
violence or treachery, and the function of ruling assumed by some other
warrior. Thus between the rudest societies and some of the lowest forms
of animal life, there is analogy alike in the slight extent to which
organization is carried, in the indefiniteness of this organization, and
in its want of fixity.

A further complication of the analogy is at hand. From the aggregation
of units into organized groups, we pass to the multiplication of such
groups, and their coalescence into compound groups. The _Hydra_, when it
has reached a certain bulk, puts forth from its surface a bud which,
growing and gradually assuming the form of the parent, finally becomes
detached; and by this process of gemmation the creature peoples the
adjacent water with others like itself. A parallel process is seen in
the multiplication of those lowly-organized tribes above described. When
one of them has increased to a size that is either too great for
co-ordination under so rude a structure, or else that is greater than
the surrounding country can supply with game and other wild food, there
arises a tendency to divide; and as in such communities there often
occur quarrels, jealousies, and other causes of division, there soon
comes an occasion on which a part of the tribe separates under the
leadership of some subordinate chief and migrates. This process being
from time to time repeated, an extensive region is at length occupied by
numerous tribes descended from a common ancestry. The analogy by no
means ends here. Though in the common _Hydra_ the young ones that bud
out from the parent soon become detached and independent; yet throughout
the rest of the class _Hydrozoa_, to which this creature belongs, the
like does not generally happen. The successive individuals thus
developed continue attached; give origin to other such individuals which
also continue attached; and so there results a compound animal. As in
the _Hydra_ itself we find an aggregation of units which, considered
separately, are akin to the lowest _Protozoa_; so here, in a _Zoophyte_,
we find an aggregation of such aggregations. The like is also seen
throughout the extensive family of _Polyzoa_ or _Molluscoida_. The
Ascidian Mollusks, too, in their many forms, show us the same thing:
exhibiting, at the same time, various degrees of union among the
component individuals. For while in the _Salpæ_ the component
individuals adhere so slightly that a blow on the vessel of water in
which they are floating will separate them; in the _Botryllidæ_ there
exist vascular connexions among them, and a common circulation. Now in
these different stages of aggregation, may we not see paralleled the
union of groups of connate tribes into nations? Though, in regions where
circumstances permit, the tribes descended from some original tribe
migrate in all directions, and become far removed and quite separate;
yet, where the territory presents barriers to distant migration, this
does not happen: the small kindred communities are held in closer
contact, and eventually become more or less united into a nation. The
contrast between the tribes of American Indians and the Scottish clans,
illustrates this. And a glance at our own early history, or the early
histories of continental nations, shows this fusion of small simple
communities taking place in various ways and to various extents. As says
M. Guizot, in his _History of the Origin of Representative
Government_,--

     "By degrees, in the midst of the chaos of the rising society, small
     aggregations are formed which feel the want of alliance and union
     with each other.... Soon inequality of strength is displayed among
     neighbouring aggregations. The strong tend to subjugate the weak,
     and usurp at first the rights of taxation and military service.
     Thus political authority leaves the aggregations which first
     instituted it, to take a wider range."

That is to say, the small tribes, clans, or feudal groups, sprung mostly
from a common stock, and long held in contact as occupants of adjacent
lands, gradually get united in other ways than by kinship and proximity.

A further series of changes begins now to take place, to which, as
before, we find analogies in individual organisms. Returning to the
_Hydrozoa_, we observe that in the simplest of the compound forms the
connected individuals are alike in structure, and perform like
functions; with the exception that here and there a bud, instead of
developing into a stomach, mouth, and tentacles, becomes an egg-sac. But
with the oceanic _Hydrozoa_ this is by no means the case. In the
_Calycophoridæ_ some of the polypes growing from the common germ, become
developed and modified into large, long, sack-like bodies, which, by
their rhythmical contractions, move through the water, dragging the
community of polypes after them. In the _Physophoridæ_ a variety of
organs similarly arise by transformation of the budding polypes; so that
in creatures like the _Physalia_, commonly known as the "Portuguese
Man-of-war," instead of that tree-like group of similar individuals
forming the original type, we have a complex mass of unlike parts
fulfilling unlike duties. As an individual _Hydra_ may be regarded as a
group of _Protozoa_ which have become partially metamorphosed into
different organs; so a _Physalia_ is, morphologically considered, a
group of _Hydræ_ of which the individuals have been variously
transformed to fit them for various functions.

This differentiation upon differentiation is just what takes place
during the evolution of a civilized society. We observed how, in the
small communities first formed, there arises a simple political
organization: there is a partial separation of classes having different
duties. And now we have to observe how, in a nation formed by the fusion
of such small communities, the several sections, at first alike in
structures and modes of activity, grow unlike in both--gradually become
mutually-dependent parts, diverse in their natures and functions.

       *       *       *       *       *

The doctrine of the progressive division of labour, to which we are here
introduced, is familiar to all readers. And further, the analogy between
the economical division of labour and the "physiological division of
labour," is so striking as long since to have drawn the attention of
scientific naturalists: so striking, indeed, that the expression
"physiological division of labour," has been suggested by it. It is not
needful, therefore, to treat this part of the subject in great detail.
We shall content ourselves with noting a few general and significant
facts, not manifest on a first inspection.

Throughout the whole animal kingdom, from the _Coelenterata_ upwards,
the first stage of evolution is the same. Equally in the germ of a
polype and in the human ovum, the aggregated mass of cells out of which
the creature is to arise, gives origin to a peripheral layer of cells,
slightly differing from the rest which they include; and this layer
subsequently divides into two--the inner, lying in contact with the
included yelk, being called the mucous layer, and the outer, exposed to
surrounding agencies, being called the serous layer: or, in the terms
used by Prof. Huxley, in describing the development of the
_Hydrozoa_--the endoderm and ectoderm. This primary division marks out a
fundamental contrast of parts in the future organism. From the mucous
layer, or endoderm, is developed the apparatus of nutrition; while from
the serous layer, or ectoderm, is developed the apparatus of external
action. Out of the one arise the organs by which food is prepared and
absorbed, oxygen imbibed, and blood purified; while out of the other
arise the nervous, muscular, and osseous systems, by the combined
actions of which the movements of the body as a whole are effected.
Though this is not a rigorously-correct distinction, seeing that some
organs involve both of these primitive membranes, yet high authorities
agree in stating it as a broad general distinction. Well, in the
evolution of a society, we see a primary differentiation of analogous
kind, which similarly underlies the whole future structure. As already
pointed out, the only manifest contrast of parts in primitive societies,
is that between the governing and the governed. In the least organized
tribes, the council of chiefs may be a body of men distinguished simply
by greater courage or experience. In more organized tribes, the
chief-class is definitely separated from the lower class, and often
regarded as different in nature--sometimes as god-descended. And later,
we find these two becoming respectively freemen and slaves, or nobles
and serfs. A glance at their respective functions, makes it obvious that
the great divisions thus early formed, stand to each other in a relation
similar to that in which the primary divisions of the embryo stand to
each other. For, from its first appearance, the warrior-class, headed by
chiefs, is that by which the external acts of the society are carried
on: alike in war, in negotiation, and in migration. Afterwards, while
this upper class grows distinct from the lower, and at the same time
becomes more and more exclusively regulative and defensive in its
functions, alike in the persons of kings and subordinate rulers,
priests, and soldiers; the inferior class becomes more and more
exclusively occupied in providing the necessaries of life for the
community at large. From the soil, with which it comes in most direct
contact, the mass of the people takes up, and prepares for use, the food
and such rude articles of manufacture as are known; while the overlying
mass of superior men, maintained by the working population, deals with
circumstances external to the community--circumstances with which, by
position, it is more immediately concerned. Ceasing by-and-by to have
any knowledge of, or power over, the concerns of the society as a whole,
the serf-class becomes devoted to the processes of alimentation; while
the noble class, ceasing to take any part in the processes of
alimentation, becomes devoted to the co-ordinated movements of the
entire body-politic.

Equally remarkable is a further analogy of like kind. After the mucous
and serous layers of the embryo have separated, there presently arises
between the two a third, known to physiologists as the vascular layer--a
layer out of which are developed the chief blood-vessels. The mucous
layer absorbs nutriment from the mass of yelk it encloses; this
nutriment has to be transferred to the overlying serous layer, out of
which the nervo-muscular system is being developed; and between the two
arises a vascular system by which the transfer is effected--a system of
vessels which continues ever after to be the transferrer of nutriment
from the places where it is absorbed and prepared, to the places where
it is needed for growth and repair. Well, may we not trace a parallel
step in social progress? Between the governing and the governed, there
at first exists no intermediate class; and even in some societies that
have reached considerable sizes, there are scarcely any but the nobles
and their kindred on the one hand, and the serfs on the other: the
social structure being such that transfer of commodities takes place
directly from slaves to their masters. But in societies of a higher
type, there grows up, between these two primitive classes, another--the
trading or middle class. Equally at first as now, we may see that,
speaking generally, this middle class is the analogue of the middle
layer in the embryo. For all traders are essentially distributors.
Whether they be wholesale dealers, who collect into large masses the
commodities of various producers; or whether they be retailers, who
divide out to those who want them, the masses of commodities thus
collected together; all mercantile men are agents of transfer from the
places where things are produced to the places where they are consumed.
Thus the distributing apparatus in a society, answers to the
distributing apparatus in a living body; not only in its functions, but
in its intermediate origin and subsequent position, and in the time of
its appearance.

Without enumerating the minor differentiations which these three great
classes afterwards undergo, we will merely note that throughout, they
follow the same general law with the differentiations of an individual
organism. In a society, as in a rudimentary animal, we have seen that
the most general and broadly contrasted divisions are the first to make
their appearance; and of the subdivisions it continues true in both
cases, that they arise in the order of decreasing generality.

Let us observe, next, that in the one case as in the other, the
specializations are at first very incomplete, and approach completeness
as organization progresses. We saw that in primitive tribes, as in the
simplest animals, there remains much community of function between the
parts which are nominally different--that, for instance, the class of
chiefs long remains industrially the same as the inferior class; just
as in a _Hydra_, the property of contractility is possessed by the units
of the endoderm as well as by those of the ectoderm. We noted also how,
as the society advanced, the two great primitive classes partook less
and less of each other's functions. And we have here to remark that all
subsequent specializations are at first vague and gradually become
distinct. "In the infancy of society," says M. Guizot, "everything is
confused and uncertain; there is as yet no fixed and precise line of
demarcation between the different powers in a state." "Originally kings
lived like other landowners, on the incomes derived from their own
private estates." Nobles were petty kings; and kings only the most
powerful nobles. Bishops were feudal lords and military leaders. The
right of coining money was possessed by powerful subjects, and by the
Church, as well as by the king. Every leading man exercised alike the
functions of landowner, farmer, soldier, statesman, judge. Retainers
were now soldiers, and now labourers, as the day required. But by
degrees the Church has lost all civil jurisdiction; the State has
exercised less and less control over religious teaching; the military
class has grown a distinct one; handicrafts have concentrated in towns;
and the spinning-wheels of scattered farmhouses, have disappeared before
the machinery of manufacturing districts. Not only is all progress from
the homogeneous to the heterogeneous, but, at the same time, it is from
the indefinite to the definite.

Another fact which should not be passed over, is that in the evolution
of a large society out of a cluster of small ones, there is a gradual
obliteration of the original lines of separation--a change to which,
also, we may see analogies in living bodies. The sub-kingdom _Annulosa_,
furnishes good illustrations. Among the lower types the body consists of
numerous segments that are alike in nearly every particular. Each has
its external ring; its pair of legs, if the creature has legs; its
equal portion of intestine, or else its separate stomach; its equal
portion of the great blood-vessel, or, in some cases, its separate
heart; its equal portion of the nervous cord; and, perhaps, its separate
pair of ganglia. But in the highest types, as in the large _Crustacea_,
many of the segments are completely fused together; and the internal
organs are no longer uniformly repeated in all the segments. Now the
segments of which nations at first consist, lose their separate external
and internal structures in a similar manner. In feudal times the minor
communities, governed by feudal lords, were severally organized in the
same rude way, and were held together only by the fealty of their
respective rulers to a suzerain. But along with the growth of a central
power, the demarcations of these local communities become relatively
unimportant, and their separate organizations merge into the general
organization. The like is seen on a larger scale in the fusion of
England, Wales, Scotland, and Ireland; and, on the Continent, in the
coalescence of provinces into kingdoms. Even in the disappearance of
law-made divisions, the process is analogous. Among the Anglo-Saxons,
England was divided into tithings, hundreds, and counties: there were
county-courts, courts of hundred, and courts of tithing. The courts of
tithing disappeared first; then the courts of hundred, which have,
however, left traces; while the county-jurisdiction still exists.
Chiefly, however, it is to be noted, that there eventually grows up an
organization which has no reference to these original divisions, but
traverses them in various directions, as is the case in creatures
belonging to the sub-kingdom just named; and, further, that in both
cases it is the sustaining organization which thus traverses old
boundaries, while, in both cases, it is the governmental, or
co-ordinating organization in which the original boundaries continue
traceable. Thus, in the highest _Annulosa_ the exo-skeleton and the
muscular system never lose all traces of their primitive segmentation;
but throughout a great part of the body, the contained viscera do not in
the least conform to the external divisions. Similarly with a nation we
see that while, for governmental purposes, such divisions as counties
and parishes still exist, the structure developed for carrying on the
nutrition of society wholly ignores these boundaries: our great
cotton-manufacture spreads out of Lancashire into North Derbyshire;
Leicestershire and Nottinghamshire have long divided the stocking-trade
between them; one great centre for the production of iron and
iron-goods, includes parts of Warwickshire, Staffordshire, and
Worcestershire; and those various specializations of agriculture which
have made different parts of England noted for different products, show
no more respect to county-boundaries than do our growing towns to the
boundaries of parishes.

If, after contemplating these analogies of structure, we inquire whether
there are any such analogies between the processes of organic change,
the answer is--yes. The causes which lead to increase of bulk in any
part of the body-politic, are of like nature with those which lead to
increase of bulk in any part of an individual body. In both cases the
antecedent is greater functional activity consequent on greater demand.
Each limb, viscus, gland, or other member of an animal, is developed by
exercise--by actively discharging the duties which the body at large
requires of it; and similarly, any class of labourers or artisans, any
manufacturing centre, or any official agency, begins to enlarge when the
community devolves on it more work. In each case, too, growth has its
conditions and its limits. That any organ in a living being may grow by
exercise, there needs a due supply of blood. All action implies waste;
blood brings the materials for repair; and before there can be growth,
the quantity of blood supplied must be more than is requisite for
repair. In a society it is the same. If to some district which
elaborates for the community particular commodities--say the woollens
of Yorkshire--there comes an augmented demand; and if, in fulfilment of
this demand, a certain expenditure and wear of the manufacturing
organization are incurred; and if, in payment for the extra quantity of
woollens sent away, there comes back only such quantity of commodities
as replaces the expenditure, and makes good the waste of life and
machinery; there can clearly be no growth. That there may be growth, the
commodities obtained in return must be more than sufficient for these
ends; and just in proportion as the surplus is great will the growth be
rapid. Whence it is manifest that what in commercial affairs we call
_profit_, answers to the excess of nutrition over waste in a living
body. Moreover, in both cases when the functional activity is high and
the nutrition defective, there results not growth but decay. If in an
animal, any organ is worked so hard that the channels which bring blood
cannot furnish enough for repair, the organ dwindles: atrophy is set up.
And if in the body-politic, some part has been stimulated into great
productivity, and cannot afterwards get paid for all its produce,
certain of its members become bankrupt, and it decreases in size.

One more parallelism to be here noted, is that the different parts of a
social organism, like the different parts of an individual organism,
compete for nutriment; and severally obtain more or less of it according
as they are discharging more or less duty. If a man's brain be
overexcited it abstracts blood from his viscera and stops digestion; or
digestion, actively going on, so affects the circulation through the
brain as to cause drowsiness; or great muscular exertion determines such
a quantity of blood to the limbs as to arrest digestion or cerebral
action, as the case may be. So, likewise, in a society, great activity
in some one direction causes partial arrests of activity elsewhere by
abstracting capital, that is commodities: as instance the way in which
the sudden development of our railway-system hampered commercial
operations; or the way in which the raising of a large military force
temporarily stops the growth of leading industries.

       *       *       *       *       *

The last few paragraphs introduce the next division of our subject.
Almost unawares we have come upon the analogy which exists between the
blood of a living body and the circulating mass of commodities in the
body-politic. We have now to trace out this analogy from its simplest to
its most complex manifestations.

In the lowest animals there exists no blood properly so called. Through
the small assemblage of cells which make up a _Hydra_, permeate the
juices absorbed from the food. There is no apparatus for elaborating a
concentrated and purified nutriment, and distributing it among the
component units; but these component units directly imbibe the
unprepared nutriment, either from the digestive cavity or from one
another. May we not say that this is what takes place in an aboriginal
tribe? All its members severally obtain for themselves the necessaries
of life in their crude states; and severally prepare them for their own
uses as well as they can. When there arises a decided differentiation
between the governing and the governed, some amount of transfer begins
between those inferior individuals who, as workers, come directly in
contact with the products of the earth, and those superior ones who
exercise the higher functions--a transfer parallel to that which
accompanies the differentiation of the ectoderm from the endoderm. In
the one case, as in the other, however, it is a transfer of products
that are little if at all prepared; and takes place directly from the
unit which obtains to the unit which consumes, without entering into any
general current.

Passing to larger organisms--individual and social--we meet the first
advance on this arrangement. Where, as among the compound _Hydrozoa_,
there is a union of many such primitive groups as form _Hydræ_; or
where, as in a _Medusa_, one of these groups has become of great size;
there exist rude channels running throughout the substance of the body:
not, however, channels for the conveyance of prepared nutriment, but
mere prolongations of the digestive cavity, through which the crude
chyle-aqueous fluid reaches the remoter parts, and is moved backwards
and forwards by the creature's contractions. Do we not find in some of
the more advanced primitive communities an analogous condition? When the
men, partially or fully united into one society, become numerous--when,
as usually happens, they cover a surface of country not everywhere alike
in its products--when, more especially, there arise considerable classes
which are not industrial; some process of exchange and distribution
inevitably arises. Traversing here and there the earth's surface,
covered by that vegetation on which human life depends, and in which, as
we say, the units of a society are imbedded, there are formed indefinite
paths, along which some of the necessaries of life occasionally pass, to
be bartered for others which presently come back along the same
channels. Note, however, that at first little else but crude commodities
are thus transferred--fruits, fish, pigs or cattle, skins, etc.: there
are few, if any, manufactured products or articles prepared for
consumption. And note also, that such distribution of these unprepared
necessaries of life as takes place, is but occasional--goes on with a
certain slow, irregular rhythm.

Further progress in the elaboration and distribution of nutriment, or of
commodities, is a necessary accompaniment of further differentiation of
functions in the individual body or in the body-politic. As fast as each
organ of a living animal becomes confined to a special action, it must
become dependent on the rest for those materials which its position and
duty do not permit it to obtain for itself; in the same way that, as
fast as each particular class of a community becomes exclusively
occupied in producing its own commodity, it must become dependent on
the rest for the other commodities it needs. And, simultaneously, a more
perfectly-elaborated blood will result from a highly specialized group
of nutritive organs, severally adapted to prepare its different
elements; in the same way that the stream of commodities circulating
throughout a society, will be of superior quality in proportion to the
greater division of labour among the workers. Observe, also, that in
either case the circulating mass of nutritive materials, besides coming
gradually to consist of better ingredients, also grows more complex. An
increase in the number of the unlike organs which add to the blood their
waste matters, and demand from it the different materials they severally
need, implies a blood more heterogeneous in composition--an _a priori_
conclusion which, according to Dr. Williams, is inductively confirmed by
examination of the blood throughout the various grades of the animal
kingdom. And similarly, it is manifest that as fast as the division of
labour among the classes of a community becomes greater, there must be
an increasing heterogeneity in the currents of merchandize flowing
throughout that community.

The circulating mass of nutritive materials in individual organisms and
in social organisms, becoming at once better in the quality of its
ingredients and more heterogeneous in composition, as the type of
structure becomes higher, eventually has added to it in both cases
another element, which is not itself nutritive but facilitates the
processes of nutrition. We refer, in the case of the individual
organism, to the blood-discs; and in the case of the social organism, to
money. This analogy has been observed by Liebig, who in his _Familiar
Letters on Chemistry_ says:--

     "Silver and gold have to perform in the organism of the state, the
     same function as the blood-corpuscles in the human organism. As
     these round discs, without themselves taking an immediate share in
     the nutritive process, are the medium, the essential condition of
     the change of matter, of the production of the heat and of the
     force by which the temperature of the body is kept up, and the
     motions of the blood and all the juices are determined, so has gold
     become the medium of all activity in the life of the state."

And blood-corpuscles being like coin in their functions, and in the fact
that they are not consumed in nutrition, he further points out that the
number of them which in a considerable interval flows through the great
centres, is enormous when compared with their absolute number; just as
the quantity of money which annually passes through the great mercantile
centres, is enormous when compared with the quantity of money in the
kingdom. Nor is this all. Liebig has omitted the significant
circumstance that only at a certain stage of organization does this
element of the circulation make its appearance. Throughout extensive
divisions of the lower animals, the blood contains no corpuscles; and in
societies of low civilization, there is no money.

Thus far we have considered the analogy between the blood in a living
body and the consumable and circulating commodities in the body-politic.
Let us now compare the appliances by which they are respectively
distributed. We shall find in the developments of these appliances
parallelisms not less remarkable than those above set forth. Already we
have shown that, as classes, wholesale and retail distributors discharge
in a society the office which the vascular system discharges in an
individual creature; that they come into existence later than the other
two great classes, as the vascular layer appears later than the mucous
and serous layers; and that they occupy a like intermediate position.
Here, however, it remains to be pointed out that a complete conception
of the circulating system in a society, includes not only the active
human agents who propel the currents of commodities, and regulate their
distribution, but includes, also, the channels of communication. It is
the formation and arrangement of these to which we now direct attention.

Going back once more to those lower animals in which there is found
nothing but a partial diffusion, not of blood, but only of crude
nutritive fluids, it is to be remarked that the channels through which
the diffusion takes place, are mere excavations through the
half-organized substance of the body: they have no lining membranes, but
are mere _lacunæ_ traversing a rude tissue. Now countries in which
civilization is but commencing, display a like condition: there are no
roads properly so called; but the wilderness of vegetal life covering
the earth's surface is pierced by tracks, through which the distribution
of crude commodities takes place. And while, in both cases, the acts of
distribution occur only at long intervals (the currents, after a pause,
now setting towards a general centre and now away from it), the transfer
is in both cases slow and difficult. But among other accompaniments of
progress, common to animals and societies, comes the formation of more
definite and complete channels of communication. Blood-vessels acquire
distinct walls; roads are fenced and gravelled. This advance is first
seen in those roads or vessels that are nearest to the chief centres of
distribution; while the peripheral roads and peripheral vessels long
continue in their primitive states. At a yet later stage of development,
where comparative finish of structure is found throughout the system as
well as near the chief centres, there remains in both cases the
difference that the main channels are comparatively broad and straight,
while the subordinate ones are narrow and tortuous in proportion to
their remoteness. Lastly, it is to be remarked that there ultimately
arise in the higher social organisms, as in the higher individual
organisms, main channels of distribution still more distinguished by
their perfect structures, their comparative straightness, and the
absence of those small branches which the minor channels perpetually
give off. And in railways we also see, for the first time in the social
organism, a system of double channels conveying currents in opposite
directions, as do the arteries and veins of a well-developed animal.

These parallelisms in the evolutions and structures of the circulating
systems, introduce us to others in the kinds and rates of the movements
going on through them. Through the lowest societies, as through the
lowest creatures, the distribution of crude nutriment is by slow
gurgitations and regurgitations. In creatures that have rude vascular
systems, just as in societies that are beginning to have roads, there is
no regular circulation along definite courses; but, instead, periodical
changes of the currents--now towards this point and now towards that.
Through each part of an inferior mollusk's body, the blood flows for a
while in one direction, then stops and flows in the opposite direction;
just as through a rudely-organized society, the distribution of
merchandize is slowly carried on by great fairs, occurring in different
localities, to and from which the currents periodically set. Only
animals of tolerably complete organizations, like advanced communities,
are permeated by constant currents that are definitely directed. In
living bodies, the local and variable currents disappear when there grow
up great centres of circulation, generating more powerful currents by a
rhythm which ends in a quick, regular pulsation. And when in social
bodies there arise great centres of commercial activity, producing and
exchanging large quantities of commodities, the rapid and continuous
streams drawn in and emitted by these centres subdue all minor and local
circulations: the slow rhythm of fairs merges into the faster one of
weekly markets, and in the chief centres of distribution, weekly markets
merge into daily markets; while in place of the languid transfer from
place to place, taking place at first weekly, then twice or thrice a
week, we by-and-by get daily transfer, and finally transfer many times a
day--the original sluggish, irregular rhythm, becomes a rapid, equable
pulse. Mark, too, that in both cases the increased activity, like the
greater perfection of structure, is much less conspicuous at the
periphery of the vascular system. On main lines of railway, we have,
perhaps, a score trains in each direction daily, going at from thirty to
fifty miles an hour; as, through the great arteries, the blood moves
rapidly in successive gushes. Along high roads, there go vehicles
conveying men and commodities with much less, though still considerable,
speed, and with a much less decided rhythm; as, in the smaller arteries,
the speed of the blood is greatly diminished and the pulse less
conspicuous. In parish-roads, narrower, less complete, and more
tortuous, the rate of movement is further decreased and the rhythm
scarcely traceable; as in the ultimate arteries. In those still more
imperfect by-roads which lead from these parish-roads to scattered
farmhouses and cottages, the motion is yet slower and very irregular;
just as we find it in the capillaries. While along the field-roads,
which, in their unformed, unfenced state, are typical of _lacunæ_, the
movement is the slowest, the most irregular, and the most infrequent; as
it is, not only in the primitive _lacunæ_ of animals and societies, but
as it is also in those _lacunæ_ in which the vascular system ends among
extensive families of inferior creatures.

Thus, then, we find between the distributing systems of living bodies
and the distributing systems of bodies-politic, wonderfully close
parallelisms. In the lowest forms of individual and social organisms,
there exist neither prepared nutritive matters nor distributing
appliances; and in both, these, arising as necessary accompaniments of
the differentiation of parts, approach perfection as this
differentiation approaches completeness. In animals, as in societies,
the distributing agencies begin to show themselves at the same relative
periods, and in the same relative positions. In the one, as in the
other, the nutritive materials circulated are at first crude and simple,
gradually become better elaborated and more heterogeneous, and have
eventually added to them a new element facilitating the nutritive
processes. The channels of communication pass through similar phases of
development, which bring them to analogous forms. And the directions,
rhythms, and rates of circulation, progress by like steps to like final
conditions.

       *       *       *       *       *

We come at length to the nervous system. Having noticed the primary
differentiation of societies into the governing and governed classes,
and observed its analogy to the differentiation of the two primary
tissues which respectively develop into organs of external action and
organs of alimentation; having noticed some of the leading analogies
between the development of industrial arrangements and that of the
alimentary apparatus; and having, above, more fully traced the analogies
between the distributing systems, social and individual; we have now to
compare the appliances by which a society, as a whole, is regulated,
with those by which the movements of an individual creature are
regulated. We shall find here parallelisms equally striking with those
already detailed.

The class out of which governmental organization originates, is, as we
have said, analogous in its relations to the ectoderm of the lowest
animals and of embryonic forms. And as this primitive membrane, out of
which the nervo-muscular system is evolved, must, even in the first
stage of its differentiation, be slightly distinguished from the rest by
that greater impressibility and contractility characterizing the organs
to which it gives rise; so, in that superior class which is eventually
transformed into the directo-executive system of a society (its
legislative and defensive appliances), does there exist in the
beginning, a larger endowment of the capacities required for these
higher social functions. Always, in rude assemblages of men, the
strongest, most courageous, and most sagacious, become rulers and
leaders; and, in a tribe of some standing, this results in the
establishment of a dominant class, characterized on the average by those
mental and bodily qualities which fit them for deliberation and
vigorous combined action. Thus that greater impressibility and
contractility, which in the rudest animal types characterize the units
of the ectoderm, characterize also the units of the primitive social
stratum which controls and fights; since impressibility and
contractility are the respective roots of intelligence and strength.

Again, in the unmodified ectoderm, as we see it in the _Hydra_, the
units are all endowed both with impressibility and contractility; but as
we ascend to higher types of organization, the ectoderm differentiates
into classes of units which divide those two functions between them:
some, becoming exclusively impressible, cease to be contractile; while
some, becoming exclusively contractile, cease to be impressible.
Similarly with societies. In an aboriginal tribe, the directive and
executive functions are diffused in a mingled form throughout the whole
governing class. Each minor chief commands those under him, and, if need
be, himself coerces them into obedience. The council of chiefs itself
carries out on the battle-field its own decisions. The head chief not
only makes laws, but administers justice with his own hands. In larger
and more settled communities, however, the directive and executive
agencies begin to grow distinct from each other. As fast as his duties
accumulate, the head chief or king confines himself more and more to
directing public affairs, and leaves the execution of his will to
others: he deputes others to enforce submission, to inflict punishments,
or to carry out minor acts of offence and defence; and only on occasions
when, perhaps, the safety of the society and his own supremacy are at
stake, does he begin to act as well as direct. As this differentiation
establishes itself, the characteristics of the ruler begin to change. No
longer, as in an aboriginal tribe, the strongest and most daring man,
the tendency is for him to become the man of greatest cunning,
foresight, and skill in the management of others; for in societies that
have advanced beyond the first stage, it is chiefly such qualities
that insure success in gaining supreme power, and holding it against
internal and external enemies. Thus that member of the governing class
who comes to be the chief directing agent, and so plays the same part
that a rudimentary nervous centre does in an unfolding organism, is
usually one endowed with some superiorities of nervous organization.

In those larger and more complex communities possessing, perhaps, a
separate military class, a priesthood, and dispersed masses of
population requiring local control, there grow up subordinate governing
agents; who, as their duties accumulate, severally become more directive
and less executive in their characters. And when, as commonly happens,
the king begins to collect round himself advisers who aid him by
communicating information, preparing subjects for his judgment, and
issuing his orders; we may say that the form of organization is
comparable to one very general among inferior types of animals, in which
there exists a chief ganglion with a few dispersed minor ganglia under
its control.

The analogies between the evolution of governmental structures in
societies, and the evolution of governmental structures in living
bodies, are, however, more strikingly displayed during the formation of
nations by coalescence of tribes--a process already shown to be, in
several respects, parallel to the development of creatures that
primarily consist of many like segments. Among other points of community
between the successive rings which make up the body in the lower
_Annulosa_, is the possession of similar pairs of ganglia. These pairs
of ganglia, though connected by nerves, are very incompletely dependent
on any general controlling power. Hence it results that when the body is
cut in two, the hinder part continues to move forward under the
propulsion of its numerous legs; and that when the chain of ganglia has
been divided without severing the body, the hind limbs may be seen
trying to propel the body in one direction while the fore limbs are
trying to propel it in another. But in the higher _Annulosa_, called
_Articulata_, sundry of the anterior pairs of ganglia, besides growing
larger, unite in one mass; and this great cephalic ganglion having
become the co-ordinator of all the creature's movements, there no longer
exists much local independence. Now may we not in the growth of a
consolidated kingdom out of petty sovereignties or baronies, observe
analogous changes? Like the chiefs and primitive rulers above described,
feudal lords, exercising supreme power over their respective groups of
retainers, discharge functions analogous to those of rudimentary nervous
centres. Among these local governing centres there is, in early feudal
times, very little subordination. They are in frequent antagonism; they
are individually restrained chiefly by the influence of parties in their
own class; and they are but irregularly subject to that most powerful
member of their order who has gained the position of head-suzerain or
king. As the growth and organization of the society progresses, these
local directive centres fall more and more under the control of a chief
directive centre. Closer commercial union between the several segments
is accompanied by closer governmental union; and these minor rulers end
in being little more than agents who administer, in their several
localities, the laws made by the supreme ruler: just as the local
ganglia above described, eventually become agents which enforce, in
their respective segments, the orders of the cephalic ganglion. The
parallelism holds still further. We remarked above, when speaking of the
rise of aboriginal kings, that in proportion as their territories
increase, they are obliged not only to perform their executive functions
by deputy, but also to gather round themselves advisers to aid in their
directive functions; and that thus, in place of a solitary governing
unit, there grows up a group of governing units, comparable to a
ganglion consisting of many cells. Let us here add that the advisers and
chief officers who thus form the rudiment of a ministry, tend from the
beginning to exercise some control over the ruler. By the information
they give and the opinions they express, they sway his judgment and
affect his commands. To this extent he is made a channel through which
are communicated the directions originating with them; and in course of
time, when the advice of ministers becomes the acknowledged source of
his actions, the king assumes the character of an automatic centre,
reflecting the impressions made on him from without.

Beyond this complication of governmental structure many societies do not
progress; but in some, a further development takes place. Our own case
best illustrates this further development and its further analogies. To
kings and their ministries have been added, in England, other great
directive centres, exercising a control which, at first small, has been
gradually becoming predominant: as with the great governing ganglia
which especially distinguish the highest classes of living beings.
Strange as the assertion will be thought, our Houses of Parliament
discharge, in the social economy, functions which are in sundry respects
comparable to those discharged by the cerebral masses in a vertebrate
animal. As it is in the nature of a single ganglion to be affected only
by special stimuli from particular parts of the body; so it is in the
nature of a single ruler to be swayed in his acts by exclusive personal
or class interests. As it is in the nature of a cluster of ganglia,
connected with the primary one, to convey to it a greater variety of
influences from more numerous organs, and thus to make its acts conform
to more numerous requirements; so it is in the nature of the subsidiary
controlling powers surrounding a king to adapt his rule to a greater
number of public exigencies. And as it is in the nature of those great
and latest-developed ganglia which distinguish the higher animals, to
interpret and combine the multiplied and varied impressions conveyed to
them from all parts of the system, and to regulate the actions in such
way as duly to regard them all; so it is in the nature of those great
and latest-developed legislative bodies which distinguish the most
advanced societies, to interpret and combine the wishes of all classes
and localities, and to make laws in harmony with the general wants. We
may describe the office of the brain as that of _averaging_ the
interests of life, physical, intellectual, moral; and a good brain is
one in which the desires answering to these respective interests are so
balanced, that the conduct they jointly dictate, sacrifices none of
them. Similarly, we may describe the office of a Parliament as that of
_averaging_ the interests of the various classes in a community; and a
good Parliament is one in which the parties answering to these
respective interests are so balanced, that their united legislation
allows to each class as much as consists with the claims of the rest.
Besides being comparable in their duties, these great directive centres,
social and individual, are comparable in the processes by which their
duties are discharged. The cerebrum is not occupied with direct
impressions from without but with the ideas of such impressions. Instead
of the actual sensations produced in the body, and directly appreciated
by the sensory ganglia, or primitive nervous centres, the cerebrum
receives only the representations of these sensations; and its
consciousness is called _representative_ consciousness, to distinguish
it from the original or _presentative_ consciousness. Is it not
significant that we have hit on the same word to distinguish the
function of our House of Commons? We call it a _representative_ body,
because the interests with which it deals are not directly presented to
it, but represented to it by its various members; and a debate is a
conflict of representations of the results likely to follow from a
proposed course--a description which applies with equal truth to a
debate in the individual consciousness. In both cases, too, these great
governing masses take no part in the executive functions. As, after a
conflict in the cerebrum, those desires which finally predominate act
on the subjacent ganglia, and through their instrumentality determine
the bodily actions; so the parties which, after a parliamentary
struggle, gain the victory, do not themselves carry out their wishes,
but get them carried out by the executive divisions of the Government.
The fulfilment of all legislative decisions still devolves on the
original directive centres: the impulse passing from the Parliament to
the Ministers and from the Ministers to the King, in whose name
everything is done; just as those smaller, first-developed ganglia,
which in the lowest vertebrata are the chief controlling agents, are
still, in the brains of the higher vertebrata, the agents through which
the dictates of the cerebrum are worked out. Moreover, in both cases
these original centres become increasingly automatic. In the developed
vertebrate animal, they have little function beyond that of conveying
impressions to, and executing the determinations of, the larger centres.
In our highly organized government, the monarch has long been lapsing
into a passive agent of Parliament; and now, ministries are rapidly
falling into the same position. Nay, between the two cases there is a
parallelism even in respect of the exceptions to this automatic action.
For in the individual creature it happens that under circumstances of
sudden alarm, as from a loud sound close at hand, an unexpected object
starting up in front, or a slip from insecure footing, the danger is
guarded against by some quick involuntary jump, or adjustment of the
limbs, which occurs before there is time to consider the impending evil
and take deliberate measures to avoid it: the rationale of which is that
these violent impressions produced on the senses, are reflected from the
sensory ganglia to the spinal cord and muscles, without, as in ordinary
cases, first passing through the cerebrum. In like manner on national
emergencies calling for prompt action, the King and Ministry, not having
time to lay the matter before the great deliberative bodies, themselves
issue commands for the requisite movements or precautions: the
primitive, and now almost automatic, directive centres, resume for a
moment their original uncontrolled power. And then, strangest of all,
observe that in either case there is an after-process of approval or
disapproval. The individual on recovering from his automatic start, at
once contemplates the cause of his fright; and, according to the case,
concludes that it was well he moved as he did, or condemns himself for
his groundless alarm. In like manner, the deliberative powers of the
State discuss, as soon as may be, the unauthorized acts of the executive
powers; and, deciding that the reasons were or were not sufficient,
grant or withhold a bill of indemnity.[28]

Thus far in comparing the governmental organization of the body-politic
with that of an individual body, we have considered only the respective
co-ordinating centres. We have yet to consider the channels through
which these co-ordinating centres receive information and convey
commands. In the simplest societies, as in the simplest organisms, there
is no "internuncial apparatus," as Hunter styled the nervous system.
Consequently, impressions can be but slowly propagated from unit to unit
throughout the whole mass. The same progress, however, which, in
animal-organization, shows itself in the establishment of ganglia or
directive centres, shows itself also in the establishment of
nerve-threads, through which the ganglia receive and convey impressions
and so control remote organs. And in societies the like eventually
takes place. After a long period during which the directive centres
communicate with various parts of the society through other means, there
at last comes into existence an "internuncial apparatus," analogous to
that found in individual bodies. The comparison of telegraph-wires to
nerves is familiar to all. It applies, however, to an extent not
commonly supposed. Thus, throughout the vertebrate sub-kingdom, the
great nerve-bundles diverge from the vertebrate axis side by side with
the great arteries; and similarly, our groups of telegraph-wires are
carried along the sides of our railways. The most striking parallelism,
however, remains. Into each great bundle of nerves, as it leaves the
axis of the body along with an artery, there enters a branch of the
sympathetic nerve; which branch, accompanying the artery throughout its
ramifications, has the function of regulating its diameter and otherwise
controlling the flow of blood through it according to local
requirements. Analogously, in the group of telegraph-wires running
alongside each railway, there is a wire for the purpose of regulating
the traffic--for retarding or expediting the flow of passengers and
commodities, as the local conditions demand. Probably, when our now
rudimentary telegraph-system is fully developed, other analogies will be
traceable.

Such, then, is a general outline of the evidence which justifies the
comparison of societies to living organisms. That they gradually
increase in mass; that they become little by little more complex; that
at the same time their parts grow more mutually dependent; and that they
continue to live and grow as wholes, while successive generations of
their units appear and disappear; are broad peculiarities which
bodies-politic display in common with all living bodies; and in which
they and living bodies differ from everything else. And on carrying out
the comparison in detail, we find that these major analogies involve
many minor analogies, far closer than might have been expected. Others
might be added. We had hoped to say something respecting the different
types of social organization, and something also on social
metamorphoses; but we have reached our assigned limits.

FOOTNOTE:

[Footnote 28: It may be well to warn the reader against an error fallen
into by one who criticised this essay on its first publication--the
error of supposing that the analogy here intended to be drawn, is a
specific analogy between the organization of society in England, and the
human organization. As said at the outset, no such specific analogy
exists. The above parallel is one between the most-developed systems of
governmental organization, individual and social; and the vertebrate
type is instanced merely as exhibiting this most-developed system. If
any specific comparison were made, which it cannot rationally be, it
would be made with some much lower vertebrate form than the human.]




THE ORIGIN OF ANIMAL WORSHIP.

    [_First published in_ The Fortnightly Review _for May,_ 1870.]


Mr. McLennan's recent essays on the Worship of Animals and Plants have
done much to elucidate a very obscure subject. By pursuing in this case,
as before in another case, the truly scientific method of comparing the
phenomena presented by existing uncivilized races with those which the
traditions of civilized races present, he has rendered both of them more
comprehensible than they were before.

It seems to me, however, that Mr. McLennan gives but an indefinite
answer to the essential question--How did the worship of animals and
plants arise? Indeed, in his concluding paper, he expressly leaves this
problem unsolved; saying that his "is not an hypothesis explanatory of
the origin of _Totemism_, be it remembered, but an hypothesis
explanatory of the animal and plant worship of the ancient nations." So
that we have still to ask--Why have savage tribes so generally taken
animals and plants and other things as totems? What can have induced
this tribe to ascribe special sacredness to one creature, and that tribe
to another? And if to these questions the reply is, that each tribe
considers itself to be descended from the object of its reverence, then
there presses for answer the further question--How came so strange a
notion into existence? If this notion occurred in one case only, we
might set it down to some whim of thought or some illusive occurrence.
But appealing, as it does, with multitudinous variations among so many
uncivilized races in different parts of the world, and having left
numerous marks in the superstitions of extinct civilized races, we
cannot assume any special or exceptional cause. Moreover, the general
cause, whatever it may be, must be such as does not negative an
aboriginal intelligence like in nature to our own. After studying the
grotesque beliefs of savages, we are apt to suppose that their reason is
not as our reason. But this supposition is inadmissible. Given the
amount of knowledge which primitive men possess, and given the imperfect
verbal symbols used by them in speech and thought, and the conclusions
they habitually reach will be those that are _relatively_ the most
rational. This must be our postulate; and, setting out with this
postulate, we have to ask how primitive men came so generally, if not
universally, to believe themselves the progeny of animals or plants or
inanimate bodies. There is, I believe, a satisfactory answer.

       *       *       *       *       *

The proposition with which Mr. McLennan sets out, that totem-worship
preceded the worship of anthropomorphic gods, is one to which I can
yield but a qualified assent. It is true in a sense, but not wholly
true. If the words "gods" and "worship" carry with them their ordinary
definite meanings, the statement is true; but if their meanings are
widened so as to comprehend those earliest vague notions out of which
the definite ideas of gods and worship are evolved, I think it is not
true. The rudimentary form of all religion is the propitiation of dead
ancestors, who are supposed to be still existing, and to be capable of
working good or evil to their descendants. As a preparation for dealing
hereafter with the principles of sociology, I have, for some years past,
directed much attention to the modes of thought current in the simpler
human societies; and evidence of many kinds, furnished by all
varieties of uncivilized men, has forced on me a conclusion harmonizing
with that lately expressed in this Review by Prof. Huxley--namely, that
the savage, conceiving a corpse to be deserted by the active personality
who dwelt in it, conceives this active personality to be still existing,
and that his feelings and ideas concerning it form the basis of his
superstitions. Everywhere we find expressed Or implied the belief that
each person is double; and that when he dies, his other self, whether
remaining near at hand or gone far away, may return, and continues
capable of injuring his enemies and aiding his friends.[29]

But how out of the desire to propitiate this second personality of a
deceased man (the words "ghost" and "spirit" are somewhat misleading,
since the savage believes that the second personality reappears in a
form equally tangible with the first), does there grow up the worship of
animals, plants, and inanimate objects? Very simply. Savages habitually
distinguish individuals by names that are either directly suggestive of
some personal trait or fact of personal history, or else express an
observed community of character with some well-known object. Such a
genesis of individual names, before surnames have arisen, is inevitable;
and how easily it arises we shall see on remembering that it still goes
on in its original form, even when no longer needful. I do not refer
only to the significant fact that in some parts of England, as in the
nail-making districts, nicknames are general, and surnames little
recognized; but I refer to a common usage among both children and
adults. The rude man is apt to be known as "a bear;" a sly fellow, as
"an old fox;" a hypocrite, as "the crocodile." Names of plants, too, are
used; as when the red-haired boy is called "carrots" by his
school-fellows. Nor do we lack nicknames derived from inorganic objects
and agents: instance that given by Mr. Carlyle to the elder
Sterling--"Captain Whirlwind." Now, in the earliest savage state, this
metaphorical naming will in most cases commence afresh in each
generation--must do so, indeed, until surnames of some kind have been
established. I say in most cases, because there will occur exceptions in
the cases of men who have distinguished themselves. If "the Wolf,"
proving famous in fight, becomes a terror to neighbouring tribes, and a
dominant man in his own, his sons, proud of their parentage, will not
let fall the fact that they descended from "the Wolf"; nor will this
fact be forgotten by the rest of the tribe who hold "the Wolf" in awe,
and see reason to dread his sons. In proportion to the power and
celebrity of "the Wolf" will this pride and this fear conspire to
maintain among his grandchildren and great-grandchildren, as well as
among those over whom they dominate, the remembrance of the fact that
their ancestor was "the Wolf". And if, as will occasionally happen, this
dominant family becomes the root of a new tribe, the members of this
tribe will become known to themselves and others as "the Wolves".

We need not rest satisfied with the inference that this inheritance of
nicknames _will_ take place. There is proof that it _does_ take place.
As nicknaming after animals, plants, and other objects, still goes on
among ourselves, so among ourselves does there go on the descent of
nicknames. An instance has come under my own notice on an estate in the
West Highlands, belonging to some friends with whom I frequently have
the pleasure of spending a few weeks in the autumn. "Take a young
Croshek," has more than once been the reply of my host to the inquiry,
who should go with me, when I was setting out salmon-fishing. The elder
Croshek I knew well; and supposed that this name, borne by him and by
all belonging to him, was the family surname. Years passed before I
learned that the real surname was Cameron; that the father was called
Croshek, after the name of his cottage, to distinguish him from other
Camerons employed about the premises; and that his children had come to
be similarly distinguished. Though here, as very generally in Scotland,
the nickname was derived from the place of residence, yet had it been
derived from an animal, the process would have been the same:
inheritance of it would have occurred just as naturally. Not even for
this small link in the argument, however, need we depend on inference.
There is fact to bear us out. Mr. Bates, in his _Naturalist on the River
Amazons_ (2d ed., p. 376), describing three half-castes who accompanied
him on a hunting trip, says--"Two of them were brothers, namely, João
(John) and Zephyrino Jabutí: Jabutí, or tortoise, being a nickname which
their father had earned for his slow gait, and which, as is usual in
this country, had descended as the surname of the family." Let me add
the statement made by Mr. Wallace respecting this same region, that "one
of the tribes on the river Isánna is called 'Jurupari' (Devils). Another
is called 'Ducks;' a third, 'Stars;' a fourth, 'Mandiocca.'" Putting
these two statements together, can there be any doubt about the genesis
of these tribal names? Let "the Tortoise" become sufficiently
distinguished (not necessarily by superiority--great inferiority may
occasionally suffice) and the tradition of descent from him, preserved
by his descendants themselves if he was superior, and by their
contemptuous neighbours if he was inferior, may become a tribal
name.[30]

"But this," it will be said, "does not amount to an explanation of
animal-worship." True: a third factor remains to be specified. Given a
belief in the still-existing other self of the deceased ancestor, who
must be propitiated; given this survival of his metaphorical name among
his grandchildren, great-grandchildren, etc.; and the further requisite
is that the distinction between metaphor and reality shall be forgotten.
Let tradition fail to keep clearly in view the fact that the ancestor
was a man called "the Wolf"--let him be habitually spoken of as "the
Wolf", just as when alive; and the natural mistake of taking the name
literally will bring with it, firstly, a belief in descent from an
actual wolf, and, secondly, a treatment of the wolf in a manner likely
to propitiate him--a manner appropriate to one who may be the other self
of the dead ancestor, or one of the kindred, and therefore a friend.

That a misunderstanding of this kind is likely to grow up, becomes
obvious when we bear in mind the great indefiniteness of
primitive language. As Prof. Max Müller says, respecting certain
misinterpretations of an opposite kind: "These metaphors ... would
become mere names handed down in the conversation of a family,
understood perhaps by the grandfather, familiar to the father, but
strange to the son, and misunderstood by the grandson." We have ample
reason, then, for supposing such misinterpretations. Nay, we may go
further. We are justified in saying that they are certain to occur. For
undeveloped languages contain no words capable of indicating the
distinction to be kept in view. In the tongues of existing inferior
races, only concrete objects and acts are expressible. The Australians
have a name for each kind of tree, but no name for tree irrespective of
kind. And though some witnesses allege that their vocabulary is not
absolutely destitute of generic names, its extreme poverty in such is
unquestionable. Similarly with the Tasmanians. Dr. Milligan says they
"had acquired very limited powers of abstraction or generalization. They
possessed no words representing abstract ideas; for each variety of
gum-tree and wattle-tree, etc., etc., they had a name, but they had no
equivalent for the expression, 'a tree;' neither could they express
abstract qualities, such as hard, soft, warm, cold, long, short, round,
etc.; for 'hard,' they would say 'like a stone;' for 'tall,' they would
say 'long legs,' etc.; and for 'round,' they said 'like a ball,' 'like
the moon,' and so on, usually suiting the action to the word, and
confirming, by some sign, the meaning to be understood."[31] Now, even
making allowance for over-statement here (which seems needful, since the
word "long," said to be inexpressible in the abstract, subsequently
occurs as qualifying a concrete in the expression, "long legs"), it is
manifest that so imperfect a language must fail to convey the idea of a
name, as something separate from a thing; and that still less can it be
capable of indicating the act of naming. Familiar use of such
partially-abstract words as are applicable to all objects of a class, is
needful before there can be reached the conception of a name--a word
symbolizing the symbolic character of other words; and the conception of
a name, with its answering abstract term, must be long current before
the verb to name can arise. Hence, men with speech so rude, cannot
transmit the tradition of an ancestor named "the Wolf", as distinguished
from the actual wolf. The children and grandchildren who saw him will
not be led into error; but in later generations, descent from "the Wolf"
will inevitably come to mean descent from the animal known by that name.
And the ideas and sentiments which, as above shown, naturally grow up
round the belief that the dead parents and grandparents are still alive,
and ready, if propitiated, to befriend their descendants, will be
extended to the wolf species.

Before passing to other developments of this general view, let me point
out how not simply animal-worship is thus accounted for, but also the
conception, so variously illustrated in ancient legends, that animals
are capable of displaying human powers of speech and thought and action.
Mythologies are full of stories of beasts and birds and fishes that have
played intelligent parts in human affairs--creatures that have
befriended particular persons by giving them information, by guiding
them, by yielding them help; or else that have deceived them, verbally
or otherwise. Evidently all these traditions, as well as those about
abductions of women by animals and fostering of children by them, fall
naturally into their places as results of the habitual misinterpretation
I have described.

       *       *       *       *       *

The probability of the hypothesis will appear still greater when we
observe how readily it applies to the worship of other orders of
objects. Belief in actual descent from an animal, strange as we may
think it, is one by no means incongruous with the unanalyzed experiences
of the savage; for there come under his notice many metamorphoses,
vegetal and animal, which are apparently of like character. But how
could he possibly arrive at so grotesque a conception as that the
progenitor of his tribe was the sun, or the moon, or a particular star?
No observation of surrounding phenomena affords the slightest suggestion
of any such possibility. But by the inheritance of nicknames that are
eventually mistaken for the names of the objects from which they were
derived, the belief readily arises--is sure to arise. That the names of
heavenly bodies will furnish metaphorical names to the uncivilized, is
manifest. Do we not ourselves call a distinguished singer or actor a
star? And have we not in poems numerous comparisons of men and women to
the sun and moon; as in _Love's Labour's Lost_, where the princess is
called "a gracious moon," and as in _Henry VII._, where we read--"Those
suns of glory, those two lights of men?" Clearly, primitive peoples will
be not unlikely thus to speak of the chief hero of a successful battle.
When we remember how the arrival of a triumphant warrior must affect the
feelings of his tribe, dissipating clouds of anxiety and brightening all
faces with joy, we shall see that the comparison of him to the sun is
quite natural; and in early speech this comparison can be made only by
calling him the sun. As before, then, it will happen that, through a
confounding of the metaphorical name with the actual name, his progeny,
after a few generations, will be regarded by themselves and others as
descendants of the sun. And, as a consequence, partly of actual
inheritance of the ancestral character, and partly of maintenance of the
traditions respecting the ancestor's achievements, it will also
naturally happen that the solar race will be considered a superior race,
as we find it habitually is.

The origin of other totems, equally strange, if not even stranger, is
similarly accounted for, though otherwise unaccountable. One of the
New-Zealand chiefs claimed as his progenitor the neighbouring great
mountain, Tongariro. This seemingly-whimsical belief becomes
intelligible when we observe how easily it may have arisen from a
nickname. Do we not ourselves sometimes speak figuratively of a tall,
fat man as a mountain of flesh? And, among a people prone to speak in
still more concrete terms, would it not happen that a chief, remarkable
for his great bulk, would be nicknamed after the highest mountain within
sight, because he towered above other men as this did above surrounding
hills? Such an occurrence is not simply possible, but probable. And, if
so, the confusion of metaphor with fact would originate this surprising
genealogy. A notion perhaps yet more grotesque, thus receives a
satisfactory interpretation. What could have put it into the imagination
of any one that he was descended from the dawn? Given the extremest
credulity, joined with the wildest fancy, it would still seem requisite
that the ancestor should be conceived as an entity; and the dawn is
entirely without that definiteness and comparative constancy which enter
into the conception of an entity. But when we remember that "the Dawn"
is a natural complimentary name for a beautiful girl opening into
womanhood, the genesis of the idea becomes, on the above hypothesis,
quite obvious.[32]

       *       *       *       *       *

Another indirect verification is that we thus get a clear conception of
Fetichism in general. Under the fetichistic mode of thought, surrounding
objects and agents are regarded as having powers more or less definitely
personal in their natures; and the current interpretation is, that human
intelligence, in its early stages, is obliged to conceive of their
powers under this form. I have myself hitherto accepted this
interpretation; though always with a sense of dissatisfaction. This
dissatisfaction was, I think, well grounded. The theory is scarcely a
theory properly so-called; but rather, a restatement in other words.
Uncivilized men _do_ habitually form anthropomorphic conceptions of
surrounding things; and this observed general fact is transformed into
the theory that at first they _must_ so conceive them--a theory for
which the psychological justification attempted, seems to me inadequate.
From our present stand-point, it becomes manifest that Fetichism is not
primary but secondary. What has been said above almost of itself shows
this. Let us, however, follow out the steps of its genesis. Respecting
the Tasmanians, Dr. Milligan says:--"The names of men and women were
taken from natural objects and occurrences around, as, for instance, a
kangaroo, a gum tree, snow, hail, thunder, the wind," flowers in
blossom, etc. Surrounding objects, then, giving origin to names of
persons, and being, in the way shown, eventually mistaken for the actual
progenitors of those who descend from persons nicknamed after them, it
results that these surrounding objects come to be regarded as in some
manner possessed of personalities like the human. He whose family
tradition is that his ancestor was "the Crab," will conceive the crab as
having a disguised inner power like his own; an alleged descent from
"the Palm-tree" will entail belief in some kind of consciousness
dwelling in the palm-tree. Hence, in proportion as the animals, plants,
and inanimate objects or agents that originate names of persons, become
numerous (which they will do in proportion as a tribe becomes large and
the number of persons to be distinguished from one another increases),
multitudinous things around will acquire imaginary personalities. And so
it will happen that, as Mr. McLennan says of the Feejeeans, "Vegetables
and stones, nay, even tools and weapons, pots and canoes, have souls
that are immortal, and that, like the souls of men, pass on at last to
Mbulu, the abode of departed spirits." Setting out, then, with a belief
in the still-living other self of the dead ancestor, the alleged general
cause of misapprehension affords us an intelligible origin of the
fetichistic conception; and we are enabled to see how it tends to become
a general, if not a universal, conception.

       *       *       *       *       *

Other apparently inexplicable phenomena are at the same time divested of
their strangeness. I refer to the beliefs in, and worship of, compound
monsters--impossible hybrid animals, and forms that are half human, half
brutal. The theory of a primordial Fetichism, supposing it otherwise
adequate, yields no feasible solutions of these. Grant the alleged
original tendency to think of all natural agencies as in some way
personal. Grant, too, that hence may arise a worship of animals, plants,
and even inanimate bodies. Still the obvious implication is that the
worship so derived will be limited to things that are, or have been,
perceived. Why should this mode of thought lead the savage to imagine a
combination of bird and mammal; and not only to imagine it, but to
worship it as a god? If even we admit that some illusion may have
suggested the belief in a creature half man, half fish, we cannot thus
explain the prevalence among Eastern races of idols representing
bird-headed men, and men having their legs replaced by the legs of a
cock, and men with the heads of elephants.

Carrying with us the inferences above drawn, however, it is a corollary
that ideas and practices of these kinds will arise. When tradition
preserves both lines of ancestry--when a chief, nicknamed "the Wolf",
carries away from an adjacent tribe a wife who is remembered either
under the animal name of her tribe, or as a woman; it will happen that
if a son distinguishes himself, the remembrance of him among his
descendants will be that he was born of a wolf and some other animal, or
of a wolf and a woman. Misinterpretation, arising in the way described
from defects of language, will entail belief in a creature uniting the
attributes of the two; and if the tribe grows into a society,
representations of such a creature will become objects of worship. One
of the cases cited by Mr. McLennan may here be repeated in illustration.
"The story of the origin of the Dikokamenni Kirgheez," they say, "from a
red greyhound and a certain queen and her forty handmaidens, is of
ancient date." Now, if "the red greyhound" was the nickname of a man
extremely swift of foot (celebrated runners have been nicknamed
"greyhound" among ourselves), a story of this kind would naturally
arise; and if the metaphorical name was mistaken for the actual name,
there might result, as the idol of the race, a compound form appropriate
to the story. We need not be surprised, then, at finding among the
Egyptians the goddess Pasht represented as a woman with a lion's head,
and the god Har-hat as a man with the head of a hawk. The Babylonian
gods--one having the form of a man with an eagle's tail, and another
uniting a human bust to a fish's body--no longer appear such
unaccountable conceptions. We get feasible explanations, too, of
sculptures representing sphinxes, winged human-headed bulls, etc.; as
well as of the stories about centaurs, satyrs, and the rest.

       *       *       *       *       *

Ancient myths in general thus acquire meanings considerably different
from those ascribed to them by comparative mythologists. Though these
last may be in part correct, yet if the foregoing argument is valid,
they can scarcely be correct in their main outlines. Indeed, if we read
the facts the other way upward, regarding as secondary or additional,
the elements that are said to be primary, while we regard as primary,
certain elements which are considered as accretions of later times, we
shall, I think, be nearer the truth.

The current theory of the myth is that it has grown out of the habit of
symbolizing natural agents and processes, in terms of human
personalities and actions. Now, it may in the first place be remarked
that, though symbolization of this kind is common among civilized races,
it is not common among races that are the most uncivilized. By existing
savages, surrounding objects, motions, and changes, are habitually used
to convey ideas respecting human transactions. It needs but to read the
speech of an Indian chief to see that just as primitive men name one
another metaphorically after surrounding objects, so do they
metaphorically describe one another's doings as though they were the
doings of natural objects. But assuming a contrary habit of thought to
be the dominant one, ancient myths are explained as results of the
primitive tendency to symbolize inanimate things and their changes, by
human beings and their doings.

A kindred difficulty must be added. The change of verbal meaning from
which the myth is said to arise, is a change opposite in kind to that
which prevails in the earlier stages of linguistic development. It
implies a derivation of the concrete from the abstract; whereas at first
abstracts are derived only from concretes: the concrete of abstracts
being a subsequent process. In the words of Prof. Max Müller, there are
"dialects spoken at the present day which have no abstract nouns, and
the more we go back in the history of languages, the smaller we find the
number of these useful expressions" (_Chips_, vol. ii., p. 54); or, as
he says more recently--"Ancient words and ancient thoughts, for both go
together, have not yet arrived at that stage of abstraction in which,
for instance, active powers, whether natural or supernatural, can be
represented in any but a personal and more or less human form."
(_Fraser's Magazine_, April, 1870.) Here the concrete is represented as
original, and the abstract as derivative. Immediately afterward,
however, Prof. Max Müller, having given as examples of abstract nouns,
"day and night, spring and winter, dawn and twilight, storm and
thunder," goes on to argue that, "as long as people thought in language,
it was simply impossible to speak of morning or evening, of spring and
winter, without giving to these conceptions something of an individual,
active, sexual, and at last, personal character." (_Chips_, vol. ii., p.
55.) Here the concrete is derived from the abstract--the personal
conception is represented as coming _after_ the impersonal conception;
and through such transformation of the impersonal into the personal,
Prof. Max Müller considers ancient myths to have arisen. How are these
propositions reconcilable? One of two things must be said:--If
originally there were none of these abstract nouns, then the earliest
statements respecting the daily course of Nature were made in concrete
terms--the personal elements of the myth were the primitive elements,
and the impersonal expressions which are their equivalents came later.
If this is not admitted, then it must be held that, until after there
arose these abstract nouns, there were no current statements at all
respecting these most conspicuous objects and changes which the heavens
and the earth present; and that the abstract nouns having been somehow
formed, and rightly formed, and used without personal meanings,
afterward became personalized--a process the reverse of that which
characterizes early linguistic progress.

No such contradictions occur if we interpret myths after the manner that
has been indicated. Nay, besides escaping contradictions, we meet with
unexpected solutions. The moment we try it, the key unlocks for us with
ease what seems a quite inexplicable fact, which the current hypothesis
takes as one of its postulates. Speaking of such words as sky and earth,
dew and rain, rivers and mountains, as well as of the abstract nouns
above named, Prof. Max Müller says--"Now in ancient languages every one
of these words had necessarily a termination expressive of gender, and
this naturally produced in the mind the corresponding idea of sex, so
that these names received not only an individual, but a sexual
character. There was no substantive which was not either masculine or
feminine; neuters being of later growth, and distinguishable chiefly in
the nominative." (_Chips_, vol. ii., p. 55.) And this alleged necessity
for a masculine or feminine implication is assigned as a part of the
reason why these abstract nouns and collective nouns became
personalized. But should not a true theory of these first steps in the
evolution of thought and language show us how it happened that men
acquired the seemingly-strange habit of so framing their words for sky,
earth, dew, rain, etc., as to make them indicative of sex? Or, at any
rate, must it not be admitted that an interpretation which, instead of
assuming this habit to be "necessary," shows us how it results, thereby
acquires an additional claim to acceptance? The interpretation I have
indicated does this. If men and women are habitually nicknamed, and if
defects of language lead their descendants to regard themselves as
descendants of the things from which the names were taken, then
masculine or feminine genders will be ascribed to these things according
as the ancestors named after them were men or women. If a beautiful
maiden known metaphorically as "the Dawn," afterwards becomes the
mother of some distinguished chief called "the North Wind," it will
result that when, in course of time, the two have been mistaken for the
actual dawn and the actual north wind, these will, by implication, be
respectively considered as male and female.

Looking, now, at the ancient myths in general, their seemingly most
inexplicable trait is the habitual combination of alleged human ancestry
and adventures, with the possession of personalities otherwise figuring
in the heavens and on the earth, with totally non-human attributes. This
enormous incongruity, not the exception but the rule, the current theory
fails to explain. Suppose it to be granted that the great terrestrial
and celestial objects and agents naturally become personalized; it does
not follow that each of them shall have a specific human biography. To
say of some star that he was the son of this king or that hero, was born
in a particular place, and when grown up carried off the wife of a
neighbouring chief, is a gratuitous multiplication of incongruities
already sufficiently great; and is not accounted for by the alleged
necessary personalization of abstract and collective nouns. As looked at
from our present stand-point, however, such traditions become quite
natural--nay, it is clear that they will necessarily arise. When a
nickname has become a tribal name, it thereby ceases to be individually
distinctive; and, as already said, the process of nicknaming inevitably
continues. It commences afresh with each child; and the nickname of each
child is both an individual name and a potential tribal name, which may
become an actual tribal name if the individual is sufficiently
celebrated. Usually, then, there is a double set of distinctions; under
one of which the individual is known by his ancestral name, and under
the other of which he is known by a name suggestive of something
peculiar to himself: just as we have seen happens among the Scotch
clans. Consider, now, what will result when language has reached a
stage of development such that it can convey the notion of naming, and
is able, therefore, to preserve traditions of human ancestry. It will
result that the individual will be known both as the son of such and
such a man by a mother whose name was so and so, and also as "the Crab",
or "the Bear", or "the Whirlwind"--supposing one of these to be his
nickname. Such joint use of nicknames and proper names occurs in every
school. Now, clearly, in advancing from the early state in which
ancestors become identified with the objects they are nicknamed after,
to the state in which there are proper names that have lost their
metaphorical meanings, there must be passed through a state in which
proper names, partially settled only, may or may not be preserved, and
in which the new nicknames are still liable to be mistaken for actual
names. Under such conditions there will arise (especially in the case of
a distinguished man) this seemingly-impossible combination of human
parentage with the possession of the non-human, or superhuman,
attributes of the thing which gave the nickname. Another anomaly
simultaneously disappears. The warrior may have, and often will have, a
variety of complimentary nicknames--"the powerful one," "the destroyer,"
etc. Supposing his leading nickname has been "the Sun"; then when he
comes to be identified by tradition with the sun, it will happen that
the sun will acquire his alternative descriptive titles--the swift one,
the lion, the wolf--titles not obviously appropriate to the sun, but
quite appropriate to the warrior. Then there comes, too, an explanation
of the remaining trait of such myths. When this identification of
conspicuous persons, male and female, with conspicuous natural agents,
has become settled, there will in due course arise interpretations of
the actions of these agents in anthropomorphic terms. Suppose, for
instance, that Endymion and Selene, metaphorically named, the one after
the setting sun, the other after the moon, have had their human
individualities merged in those of the sun and moon, through
misinterpretation of metaphors; what will happen? The legend of their
loves having to be reconciled with their celestial appearances and
motions, these will be spoken of as results of feeling and will; so that
when the sun is going down in the west, while the moon in mid-heaven is
following him, the fact will be expressed by saying: "Selene loves and
watches Endymion." Thus we obtain a consistent explanation of the myth
without distorting it; and without assuming that it contains gratuitous
fictions. We are enabled to accept the biographical part of it, if not
as literal fact, still as having had fact for its root. We are helped to
see how, by an inevitable misinterpretation, there grew out of a more or
less true tradition, this strange identification of its personages, with
objects and powers totally non-human in their aspects. And then we are
shown how, from the attempt to reconcile in thought these contradictory
elements of the myth, there arose the habit of ascribing the actions of
these non-human things to human motives.

One further verification may be drawn from facts which are obstacles to
the converse hypothesis. These objects and powers, celestial and
terrestrial, which force themselves most on men's attention, have some
of them several proper names, identified with those of different
individuals, born at different places, and having different sets of
adventures. Thus we have the sun variously known as Apollo, Endymion,
Helios, Tithonos, etc.--personages having irreconcilable genealogies.
Such anomalies Prof. Max Müller apparently ascribes to the
untrustworthiness of traditions, which are "careless about
contradictions, or ready to solve them sometimes by the most atrocious
expedients." (_Chips_, vol. ii., p. 84.) But if the evolution of the
myth has been that above indicated, there exists no anomalies to be got
rid of: these diverse genealogies become parts of the evidence. For we
have abundant proof that the same objects furnish metaphorical names of
men in different tribes. There are Duck tribes in Australia, in South
America, in North America. The eagle is still a totem among the North
Americans, as Mr. McLennan shows reason to conclude that it was among
the Egyptians, among the Jews, and among the Romans. Obviously, for
reasons already assigned, it naturally happened in the early stages of
the ancient races, that complimentary comparisons of their heroes to the
Sun were frequently made. What resulted? The Sun having furnished names
for sundry chiefs and early founders of tribes, and local traditions
having severally identified them with the Sun, these tribes, when they
grew, spread, conquered, or came otherwise into partial union,
originated a combined mythology, which necessarily contained conflicting
stories about the Sun-god, as about its other leading personages. If the
North-American tribes, among several of which there are traditions of a
Sun-god, had developed a combined civilization, there would similarly
have arisen among them a mythology which ascribed to the Sun several
different proper names and genealogies.

       *       *       *       *       *

Let me briefly set down the leading characters of this hypothesis which
give it probability.

True interpretations of all the natural processes, organic and
inorganic, that have gone on in past times, habitually trace them to
causes still in action. It is thus in Geology; it is thus in Biology; it
is thus in Philology. Here we find this characteristic repeated.
Nicknaming, the inheritance of nicknames, and to some extent, the
misinterpretation of nicknames, go on among us still; and were surnames
absent, language imperfect, and knowledge as rudimentary as of old, it
is tolerably manifest that results would arise like those we have
contemplated.

A further characteristic of a true cause is that it accounts not only
for the particular group of phenomena to be interpreted, but also for
other groups. The cause here alleged does this. It equally well explains
the worship of animals, of plants, of mountains, of winds, of celestial
bodies, and even of appearances too vague to be considered entities. It
gives us an intelligible genesis of fetichistic conceptions in general.
It furnishes us with a reason for the practice, otherwise so
unaccountable, of moulding the words applied to inanimate objects in
such ways as to imply masculine and feminine genders. It shows us how
there naturally arose the worship of compound animals, and of monsters
half man, half brute. And it shows us why the worship of purely
anthropomorphic deities came later, when language had so far developed
that it could preserve in tradition the distinction between proper names
and nicknames.

A further verification of this view is, that it conforms to the general
law of evolution: showing us how, out of one simple, vague, aboriginal
form of belief, there have arisen, by continuous differentiations, the
many heterogeneous forms of belief which have existed and do exist. The
desire to propitiate the other self of the dead ancestor, displayed
among savage tribes, dominantly manifested by the early historic races,
by the Peruvians and Mexicans, by the Chinese at the present time, and
to a considerable degree by ourselves (for what else is the wish to do
that which a lately-deceased parent was known to have desired?) has been
the universal first form of religious belief; and from it have grown up
the many divergent beliefs which have been referred to.

Let me add, as a further reason for adopting this view, that it
immensely diminishes the apparently-great contrast between early modes
of thought and our own mode of thought. Doubtless the aboriginal man
differs considerably from us, both in intellect and feeling. But such an
interpretation of the facts as helps us to bridge over the gap, derives
additional likelihood from doing this. The hypothesis I have sketched
out enables us to see that primitive ideas are not so gratuitously
absurd as we suppose, and also enables us to rehabilitate the ancient
myth with far less distortion than at first sight appears possible.

These views I hope to develop in the first part of _The Principles of
Sociology_. The large mass of evidence which I shall be able to give in
support of the hypothesis, joined with the solutions it will be shown to
yield of many minor problems which I have passed over, will, I think,
then give to it a still greater probability than it seems now to have.

FOOTNOTES:

[Footnote 29: A critical reader may raise an objection. If
animal-worship is to be rationally interpreted, how can the
interpretation set out by assuming a belief in the spirits of dead
ancestors--a belief which just as much requires explanation? Doubtless
there is here a wide gap in the argument. I hope eventually to fill it
up. Here, out of many experiences which conspire to generate this
belief, I can but briefly indicate the leading ones: 1. It is not
impossible that his shadow, following him everywhere, and moving as he
moves, may have some small share in giving to the savage a vague idea of
his duality. It needs but to watch a child's interest in the movements
of its shadow, and to remember that at first a shadow cannot be
interpreted as a negation of light, but is looked upon as an entity, to
perceive that the savage may very possibly consider it as a specific
something which forms part of him. 2. A much more decided suggestion of
the same kind is likely to result from the reflection of his face and
figure in water: imitating him as it does in his form, colours, motions,
grimaces. When we remember that not unfrequently a savage objects to
have his portrait taken, because he thinks whoever carries away a
representation of him carries away some part of his being, we see how
probable it is that he thinks his double in the water is a reality in
some way belonging to him. 3. Echoes must greatly tend to confirm the
idea of duality otherwise arrived at. Incapable as he is of
understanding their natural origin, the primitive man necessarily
ascribes them to living beings--beings who mock him and elude his
search. 4. The suggestions resulting from these and other physical
phenomena are, however, secondary in importance. The root of this belief
in another self lies in the experience of dreams. The distinction so
easily made by us between our life in dreams and our real life, is one
which the savage recognizes in but a vague way; and he cannot express
even that distinction which he perceives. When he awakes, and to those
who have seen him lying quietly asleep, describes where he has been, and
what he has done, his rude language fails to state the difference
between seeing and dreaming that he saw, doing and dreaming that he did.
From this inadequacy of his language it not only results that he cannot
truly represent this difference to others, but also that he cannot truly
represent it to himself. Hence, in the absence of an alternative
interpretation, his belief, and that of those to whom he tells his
adventures, is that his other self has been away, and came back when he
awoke. And this belief, which we find among various existing savage
tribes, we equally find in the traditions of the early civilized races.
5. The conception of another self capable of going away and returning,
receives what to the savage must seem conclusive verifications from the
abnormal suspensions of consciousness, and derangements of
consciousness, that occasionally occur in members of his tribe. One who
has fainted, and cannot be immediately brought back to himself (note the
significance of our own phrases "returning to himself," etc.) as a
sleeper can, shows him a state in which the other self has been away for
a time beyond recall. Still more is this prolonged absence of the other
self shown him in cases of apoplexy, catalepsy, and other forms of
suspended animation. Here for hours the other self persists in remaining
away, and on returning refuses to say where he has been. Further
verification is afforded by every epileptic subject, into whose body,
during the absence of the other self, some enemy has entered; for how
else does it happen that the other self, on returning, denies all
knowledge of what his body has been doing? And this supposition that the
body has been "possessed" by some other being, is confirmed by the
phenomena of somnambulism and insanity. 6. What, then, is the
interpretation inevitably put upon death? The other self has habitually
returned after sleep, which simulates death. It has returned, too, after
fainting, which simulates death much more. It has even returned after
the rigid state of catalepsy, which simulates death very greatly. Will
it not return also after this still more prolonged quiescence and
rigidity? Clearly it is quite possible--quite probable even. The dead
man's other self is gone away for a long time, but it still exists
somewhere, far or near, and may at any moment come back to do all he
said he would do. Hence the various burial-rites--the placing of weapons
and valuables along with the body, the daily bringing of food to it,
etc. I hope hereafter to show that, with such knowledge of the facts as
he has, this interpretation is the most reasonable the savage can arrive
at. Let me here, however, by way of showing how clearly the facts bear
out this view, give one illustration out of many. "The ceremonies with
which they [the Veddahs] invoke them [the shades of the dead] are few as
they are simple. The most common is the following. An arrow is fixed
upright in the ground, and the Veddah dances slowly round it, chanting
this invocation, which is almost musical in its rhythm:"

     "Mâ miya, mâ miy, mâ deyâ,
     Topang koyihetti mittigan yandâh?"

   "My departed one, my departed one, my God!
   Where art thou wandering?"

"This invocation appears to be used on all occasions when the
intervention of the guardian spirits is required, in sickness,
preparatory to hunting, etc. Sometimes, in the latter case, a portion of
the flesh of the game is promised as a votive offering, in the event of
the chase being successful; and they believe that the spirits will
appear to them in dreams and tell them where to hunt. Sometimes they
cook food and place it in the dry bed of a river, or some other secluded
spot, and then call on their deceased ancestors by name. 'Come and
partake of this! Give us maintenance as you did when living! Come,
wheresoever you may be; on a tree, on a rock, in the forest, come!' And
they dance round the food, half chanting, half shouting, the
invocation."--Bailey, in _Transactions of the Ethnological Society_,
London, N. S., ii., p. 301-2.]

[Footnote 30: Since the foregoing pages were written, my attention has
been drawn by Sir John Lubbock to a passage in the appendix to the
second edition of _Prehistoric Times_, in which he has indicated this
derivation of tribal names. He says: "In endeavouring to account for the
worship of animals, we must remember that names are very frequently
taken from them. The children and followers of a man called the Bear or
the Lion would make that a tribal name. Hence the animal itself would be
first respected, at last worshipped." Of the genesis of this worship,
however, Sir John Lubbock does not give any specific explanation.
Apparently he inclines to the belief, tacitly adopted also by Mr.
McLennan, that animal-worship is derived from an original Fetichism, of
which it is a more developed form. As will shortly be seen, I take a
different view of its origin.]

[Footnote 31: _Proceedings of the Royal Society of Tasmania_, iii., p.
280-81.]

[Footnote 32: I have since found, however, that the name Dawn, which
occurs in various places, seems more frequently a birth-name, given
because the birth took place at dawn.]




MORALS AND MORAL SENTIMENTS.

    [_First published in_ The Fortnightly Review _for April,_ 1871.]


If a writer who discusses unsettled questions takes up every gauntlet
thrown down to him, polemical writing will absorb much of his energy.
Having a power of work which unfortunately does not suffice for
executing with anything like due rapidity the task I have undertaken, I
have made it a policy to avoid controversy as much as possible, even at
the cost of being seriously misunderstood. Hence it resulted that when
in _Macmillan's Magazine_, for July, 1869, Mr. Richard Hutton published,
under the title "A Questionable Parentage for Morals," a criticism on a
doctrine of mine, I decided to let his misrepresentations pass unnoticed
until, in the course of my work, I arrived at the stage where, by a full
exposition of this doctrine, they would be set aside. It did not occur
to me that, in the meantime, these erroneous statements, accepted as
true statements, would be repeated by other writers, and my views
commented upon as untenable. This, however, has happened. In more
periodicals than one, I have seen it asserted that Mr. Hutton has
effectually disposed of my hypothesis. Supposing that this hypothesis
has been rightly expressed by Mr. Hutton, Sir John Lubbock, in his
_Origin of Civilisation_, &c., has been led to express a partial
dissent; which I think he would not have expressed had my own
exposition been before him. Mr. Mivart, too, in his recent _Genesis of
Species_, has been similarly betrayed into misapprehensions. And now Sir
Alexander Grant, following the same lead, has conveyed to the readers of
the _Fortnightly Review_ another of these conceptions, which is but very
partially true. Thus I find myself compelled to say as much as will
serve to prevent further spread of the mischief.

       *       *       *       *       *

If a general doctrine concerning a highly-involved class of phenomena
could be adequately presented in a single paragraph of a letter, the
writing of books would be superfluous. In the brief exposition of
certain ethical doctrines held by me, which is given in Professor Bain's
_Mental and Moral Science_, it is stated that they are--

     "as yet, nowhere fully expressed. They form part of the more
     general doctrine of Evolution which he is engaged in working out;
     and they are at present to be gathered only from scattered
     passages. It is true that, in his first work, _Social Statics_, he
     presented what he then regarded as a tolerably complete view of one
     division of Morals. But without abandoning this view, he now
     regards it as inadequate--more especially in respect of its basis."

Mr. Hutton, however, taking the bare enunciation of one part of this
basis, deals with it critically; and, in the absence of any exposition
by me, sets forth what he supposes to be my grounds for it, and proceeds
to show that they are unsatisfactory.

If, in his anxiety to suppress what he doubtless regards as a pernicious
doctrine, Mr. Hutton could not wait until I had explained myself, it
might have been expected that he would use whatever information was to
be had concerning it. So far from seeking out such information, however,
he has, in a way for which I cannot account, ignored the information
immediately before him.

The title which Mr. Hutton has chosen for his criticism is, "A
Questionable Parentage for Morals." Now he has ample means of knowing
that I allege a primary basis of Morals, quite independent of that
which he describes and rejects. I do not refer merely to the fact that
having, when he reviewed _Social Statics_,[33] expressed his very
decided dissent from this primary basis, he must have been aware that I
alleged it; for he may say that in the many years which have since
elapsed he had forgotten all about it. But I refer to the distinct
enunciation of this primary basis in that letter to Mr. Mill from which
he quotes. In a preceding paragraph of the letter, I have explained
that, while I accept utilitarianism in the abstract, I do not accept
that current utilitarianism which recognizes for the guidance of conduct
nothing beyond empirical generalizations; and I have contended that--

     "Morality, properly so-called--the science of right conduct--has
     for its object to determine _how_ and _why_ certain modes of
     conduct are detrimental, and certain other modes beneficial. These
     good and bad results cannot be accidental, but must be necessary
     consequences of the constitution of things; and I conceive it to be
     the business of Moral Science to deduce, from the laws of life and
     the conditions of existence, what kinds of action necessarily tend
     to produce happiness, and what kinds to produce unhappiness. Having
     done this, its deductions are to be recognised as laws of conduct;
     and are to be conformed to irrespective of a direct estimation of
     happiness or misery."

Nor is this the only enunciation of what I conceive to be the primary
basis of morals, contained in this same letter. A subsequent paragraph
separated by four lines only from that which Mr. Hutton extracts,
commences thus:--

    "Progressing civilization, which is of necessity a succession of
    compromises between old and new, requires a perpetual re-adjustment
    of the compromise between the ideal and the practicable in social
    arrangements: to which end, both elements of the compromise must be
    kept in view. If it is true that pure rectitude prescribes a system
    of things far too good for men as they are, it is not less true that
    mere expediency does not of itself tend to establish a system of
    things any better than that which exists. While absolute morality
    owes to expediency the checks which prevent it from rushing into
    Utopian absurdities, expediency is indebted to absolute morality for
    all stimulus to improvement. Granted that we are chiefly interested
    in ascertaining what is _relatively right_, it still follows that we
     must first consider what is _absolutely right_; since the one
    conception presupposes the other."

I do not see how there could well be a more emphatic assertion that
there exists a primary basis of morals independent of, and in a sense
antecedent to, that which is furnished by experiences of utility; and
consequently, independent of, and, in a sense antecedent to, those moral
sentiments which I conceive to be generated by such experiences. Yet no
one could gather from Mr. Hutton's article that I assert this; or would
even find reasons for a faint suspicion that I do so. From the reference
made to my further views, he would infer my acceptance of that empirical
utilitarianism which I have expressly repudiated. And the title which
Mr. Hutton gives to his paper clearly asserts, by implication, that I
recognize no "parentage for morals" beyond that of the accumulation and
organization of the effects of experience. I cannot believe that Mr.
Hutton intended to convey this erroneous impression. He was, I suppose,
too much absorbed in contemplating the proposition he combats to
observe, or, at least, to attach any weight to, the propositions which
accompany it. But I am sorry he did not perceive the mischief he was
likely to do me by spreading this one-sided statement.

       *       *       *       *       *

I pass now to the particular question at issue--not the "parentage for
morals," but the parentage of moral sentiments. In describing my view on
this more special doctrine, Mr. Hutton has similarly, I regret to say,
neglected the data which would have helped him to draw an approximately
true outline of it. It cannot well be that the existence of such data
was unknown to him. They are contained in the _Principles of
Psychology_; and Mr. Hutton reviewed that work when it was first
published.[34] In a chapter on the Feelings, which occurs near the end
of it, there is sketched out a process of evolution by no means like
that which Mr. Hutton indicates; and had he turned to that chapter he
would have seen that his description of the genesis of moral sentiments
out of organized experiences is not such a one as I should have given.
Let me quote a passage from that chapter.

     "Not only are those emotions which form the immediate stimuli to
     actions, thus explicable; but the like explanation applies to the
     emotions that leave the subject of them comparatively passive: as,
     for instance, the emotion produced by beautiful scenery. The
     gradually increasing complexity in the groups of sensations and
     ideas co-ordinated, ends in the co-ordination of those vast
     aggregations of them which a grand landscape excites and suggests.
     The infant taken into the midst of mountains, is totally unaffected
     by them; but is delighted with the small group of attributes and
     relations presented in a toy. The child can appreciate, and be
     pleased with, the more complicated relations of household objects
     and localities, the garden, the field, and the street. But it is
     only in youth and mature age, when individual things and small
     assemblages of them have become familiar and automatically
     cognizable, that those immense assemblages which landscapes present
     can be adequately grasped, and the highly aggregated states of
     consciousness produced by them, experienced. Then, however, the
     various minor groups of states that have been in earlier days
     severally produced by trees, by fields, by streams, by cascades, by
     rocks, by precipices, by mountains, by clouds, are aroused
     together. Along with the sensations immediately received, there are
     partially excited the myriads of sensations that have been in times
     past received from objects such as those presented; further, there
     are partially excited the various incidental feelings that were
     experienced on all these countless past occasions; and there are
     probably also excited certain deeper, but now vague combinations of
     states, that were organized in the race during barbarous times,
     when its pleasurable activities were chiefly among the woods and
     waters. And out of all these excitations, some of them actual but
     most of them nascent, is composed the emotion which a fine
     landscape produces in us."

It is, I think, amply manifest that the processes here indicated are not
to be taken as intellectual processes--not as processes in which
recognized relations between pleasures and their antecedents, or
intelligent adaptations of means to ends, form the dominant elements.
The state of mind produced by an aggregate of picturesque objects is not
one resolvable into propositions. The sentiment does not contain within
itself any consciousness of causes and consequences of happiness. The
vague recollections of other beautiful scenes and other delightful days
which it dimly rouses, are not aroused because of any rational
co-ordinations of ideas that have been formed in bygone years. Mr.
Hutton, however, assumes that in speaking of the genesis of moral
feelings as due to inherited experiences of the pleasures and pains
caused by certain modes of conduct, I am speaking of reasoned-out
experiences--experiences consciously accumulated and generalized. He
overlooks the fact that the genesis of emotions is distinguished from
the genesis of ideas in this; that whereas the ideas are composed of
elements that are simple, definitely related, and (in the case of
general ideas) constantly related, emotions are composed of enormously
complex aggregates of elements that are never twice alike, and which
stand in relations that are never twice alike. The difference in the
resulting modes of consciousness is this:--In the genesis of an idea the
successive experiences, be they of sounds, colours, touches, tastes, or
be they of the special objects which combine many of these into groups,
have so much in common that each, when it occurs, can be definitely
thought of as like those which preceded it. But in the genesis of an
emotion the successive experiences so far differ that each of them, when
it occurs, suggests past experiences which are not specifically similar,
but have only a general similarity; and, at the same time, it suggests
benefits or evils in past experience which likewise are various in their
special natures, though they have a certain community in general nature.
Hence it results that the consciousness aroused is a multitudinous,
confused consciousness, in which, along with a certain kind of
combination among the impressions received from without, there is a
vague cloud of ideal combinations akin to them, and a vague mass of
ideal feelings of pleasure or pain which were associated with these. We
have abundant proof that feelings grow up without reference to
recognized causes and consequences, and without the possessor of them
being able to say why they have grown up; though analysis,
nevertheless, shows that they have been formed out of connected
experiences. The familiar fact that a kind of jam which was, during
childhood, repeatedly taken after medicine, may become, by simple
association of sensations, so nauseous that it cannot be tolerated in
after-life, illustrates clearly the way in which repugnances may be
established by habitual association of feelings, without any belief in
causal connexion; or rather, in spite of the knowledge that there is no
causal connexion. Similarly with pleasurable emotions. The cawing of
rooks is not in itself an agreeable sound: musically considered, it is
very much the contrary. Yet the cawing of rooks usually produces in
people feelings of a grateful kind--feelings which most of them suppose
to result from the quality of the sound itself. Only the few who are
given to self-analysis are aware that the cawing of rooks is agreeable
to them because it has been connected with countless of their greatest
gratifications--with the gathering of wild flowers in childhood; with
Saturday-afternoon excursions in school-boy days; with midsummer
holidays in the country, when books were thrown aside and lessons were
replaced by games and adventures in the fields; with fresh, sunny
mornings in after-years, when a walking excursion was an immense relief
from toil. As it is, this sound, though not causally related to all
these multitudinous and varied past delights, but only often associated
with them, can no more be heard without rousing a dim consciousness of
these delights, than the voice of an old friend unexpectedly coming into
the house can be heard without suddenly raising a wave of that feeling
that has resulted from the pleasures of past companionship. If we are to
understand the genesis of emotions, either in the individual or in the
race, we must take account of this all-important process. Mr. Hutton,
however, apparently overlooking it, and not having reminded himself, by
referring to the _Principles of Psychology_, that I insist upon it,
represents my hypothesis to be that a certain sentiment results from the
consolidation of intellectual conclusions! He speaks of me as believing
that "what seems to us now the 'necessary' intuitions and _a priori_
assumptions of human nature, are likely to prove, when scientifically
analysed, nothing but a similar conglomeration of our ancestors' _best
observations and most useful empirical rules_." He supposes me to think
that men having, in past times, come to _see_ that truthfulness was
useful, "the habit of approving truth-speaking and fidelity to
engagements, which was first based on this ground of utility, became so
rooted, that the utilitarian ground of it was forgotten, and _we_ find
ourselves springing to the belief in truth-speaking and fidelity to
engagements from an inherited tendency." Similarly throughout, Mr.
Hutton has so used the word "utility," and so interpreted it on my
behalf, as to make me appear to mean that moral sentiment is formed out
of _conscious generalizations_ respecting what is beneficial and what
detrimental. Were such my hypothesis, his criticisms would be very much
to the point; but as such is not my hypothesis, they fall to the ground.
The experiences of utility I refer to are those which become registered,
not as distinctly recognized connexions between certain kinds of acts
and certain kinds of remote results, but those which become registered
in the shape of associations between groups of feelings that have often
recurred together, though the relation between them has not been
consciously generalized--associations the origin of which may be as
little perceived as is the origin of the pleasure given by the sounds of
a rookery; but which, nevertheless, have arisen in the course of daily
converse with things, and serve as incentives or deterrents.

In the paragraph which Mr. Hutton has extracted from my letter to Mr.
Mill, I have indicated an analogy between those effects of emotional
experiences out of which I believe moral sentiments have been developed,
and those effects of intellectual experiences out of which I believe
space-intuitions have been developed. Rightly considering that the first
of these hypotheses cannot stand if the last is disproved, Mr. Hutton
has directed part of his attack against this last. But would it not have
been well if he had referred to the _Principles of Psychology_, where
this last hypothesis is set forth at length, before criticising it?
Would it not have been well to give an abstract of my own description of
the process, instead of substituting what he _supposes_ my description
must be? Any one who turns to the _Principles of Psychology_ (first
edition, pp. 218-245), and reads the two chapters, "The Perception of
Body as presenting Statical Attributes", and "The Perception of Space",
will find that Mr. Hutton's account of my view on this matter has given
him no notion of the view as it is expressed by me; and will, perhaps,
be less inclined to smile than he was when he read Mr. Hutton's account.
I cannot here do more than thus imply the invalidity of such part of Mr.
Hutton's argument as proceeds upon this incorrect representation. The
pages which would be required for properly explaining the doctrine that
space-intuitions result from organized experiences may be better used
for explaining this analogous doctrine at present before us. This I will
now endeavour to do; not indirectly by correcting misapprehensions, but
directly by an exposition which shall be as brief as the extremely
involved nature of the process allows.

An infant in arms, when old enough to gaze at objects around with some
vague recognition, smiles in response to the laughing face and soft
caressing voice of its mother. Let there come some one who, with an
angry face, speaks to it in loud, harsh tones. The smile disappears, the
features contract into an expression of pain, and, beginning to cry, it
turns away its head, and makes such movements of escape as are possible.
What is the meaning of these facts? Why does not the frown make it
smile, and the mother's laugh make it weep? There is but one answer.
Already in its developing brain there is coming into play the structure
through which one cluster of visual and auditory impressions excites
pleasurable feelings, and the structure through which another cluster of
visual and auditory impressions excites painful feelings. The infant
knows no more about the relation existing between a ferocious expression
of face, and the evils which may follow perception of it, than the young
bird just out of its nest knows of the possible pain and death which may
be inflicted by a man coming towards it; and as certainly in the one
case as in the other, the alarm felt is due to a partially-established
nervous structure. Why does this partially-established nervous structure
betray its presence thus early in the human being? Simply because, in
the past experiences of the human race, smiles and gentle tones in those
around have been the habitual accompaniments of pleasurable feelings;
while pains of many kinds, immediate and more or less remote, have been
continually associated with the impressions received from knit brows,
and set teeth, and grating voice. Much deeper down than the history of
the human race must we go to find the beginnings of these connexions.
The appearances and sounds which excite in the infant a vague dread,
indicate danger; and do so because they are the physiological
accompaniments of destructive action--some of them common to man and
inferior mammals, and consequently understood by inferior mammals, as
every puppy shows us. What we call the natural language of anger, is due
to a partial contraction of those muscles which actual combat would call
into play; and all marks of irritation, down to that passing shade over
the brow which accompanies slight annoyance, are incipient stages of
these same contractions. Conversely with the natural language of
pleasure, and of that state of mind which we call amicable feeling:
this, too, has a physiological interpretation.[35]

Let us pass now from the infant in arms to the children in the nursery.
What have the experiences of each been doing in aid of the emotional
development we are considering? While its limbs have been growing more
agile by exercise, its manipulative skill increasing by practice, its
perceptions of objects growing by use quicker, more accurate, more
comprehensive; the associations between these two sets of impressions
received from those around, and the pleasures and pains received along
with them, or after them, have been by frequent repetition made
stronger, and their adjustments better. The dim sense of pain and the
vague glow of delight which the infant felt, have, in the urchin,
severally taken shapes that are more definite. The angry voice of a
nursemaid no longer arouses only a formless feeling of dread, but also a
specific idea of the slap that may follow. The frown on the face of a
bigger brother, along with the primitive, indefinable sense of ill,
brings the ideas of ills that are definable as kicks, and cuffs, and
pullings of hair, and losses of toys. The faces of parents, looking now
sunny, now gloomy, have grown to be respectively associated with
multitudinous forms of gratification and multitudinous forms of
discomfort or privation. Hence these appearances and sounds, which imply
amity or enmity in those around, become symbolic of happiness and
misery; so that eventually, perception of the one set or the other can
scarcely occur without raising a wave of pleasurable feeling or of
painful feeling. The body of this wave is still substantially of the
same nature as it was at first; for though in each of these
multitudinous experiences a special set of facial and vocal signs has
been connected with a special set of pleasures or pains; yet since these
pleasures or pains have been immensely varied in their kinds and
combinations, and since the signs that preceded them were in no two
cases quite alike, it results that even to the end the consciousness
produced remains as vague as it is voluminous. The thousands of
partially-aroused ideas resulting from past experiences are massed
together and superposed, so as to form an aggregate in which nothing is
distinct, but which has the character of being pleasurable or painful
according to the nature of its original components: the chief difference
between this developed feeling and the feeling aroused in the infant
being, that on bright or dark background forming the body of it, may now
be sketched out in thought the particular pleasures or pains which the
particular circumstances suggest as likely.

What must be the working of this process under the conditions of
aboriginal life? The emotions given to the young savage by the natural
language of love and hate in the members of his tribe, gain first a
partial definiteness in respect to his intercourse with his family and
playmates; and he learns by experience the utility, in so far as his own
ends are concerned, of avoiding courses which call from others
manifestations of anger, and taking courses which call from them
manifestations of pleasure. Not that he consciously generalizes. He does
not at that age, probably not at any age, formulate his experiences in
the general principle that it is well for him to do things which bring
smiles, and to avoid doing things which bring frowns. What happens is
that having, in the way shown, inherited this connexion between the
perception of anger in others and the feeling of dread, and having
discovered that certain acts of his bring on this anger, he cannot
subsequently think of committing one of these acts without thinking of
the resulting anger, and feeling more or less of the resulting dread. He
has no thought of the utility or inutility of the act itself: the
deterrent is the mainly vague, but partially definite, fear of evil that
may follow. So understood, the deterring emotion is one which has grown
out of experiences of utility, using that word in its ethical sense; and
if we ask why this dreaded anger is called forth from others, we shall
habitually find that it is because the forbidden act entails pain
somewhere--is negatived by utility. On passing from domestic injunctions
to injunctions current in the tribe, we see no less clearly how these
emotions produced by approbation and reprobation come to be connected in
experience with actions which are beneficial to the tribe, and actions
which are detrimental to the tribe; and how there consequently grow up
incentives to the one class of actions and prejudices against the other
class. From early boyhood the young savage hears recounted the daring
deeds of his chief--hears them in words of praise, and sees all faces
glowing with admiration. From time to time also he listens while some
one's cowardice is described in tones of scorn, and with contemptuous
metaphors, and sees him meet with derision and insult whenever he
appears. That is to say, one of the things that come to be associated in
his mind with smiling faces, which are symbolical of pleasures in
general, is courage; and one of the things that come to be associated in
his mind with frowns and other marks of enmity, which form his symbol of
unhappiness, is cowardice. These feelings are not formed in him because
he has reasoned his way to the truth that courage is useful to the
tribe, and, by implication, to himself, or to the truth that cowardice
is a cause of evil. In adult life he may perhaps see this; but he
certainly does not see it at the time when bravery is thus joined in his
consciousness with all that is good, and cowardice with all that is bad.
Similarly there are produced in him feelings of inclination or
repugnance towards other lines of conduct that have become established
or interdicted, because they are beneficial or injurious to the tribe;
though neither the young nor the adults know why they have become
established or interdicted. Instance the praiseworthiness of
wife-stealing, and the viciousness of marrying within the tribe.

We may now ascend a stage to an order of incentives and restraints
derived from these. The primitive belief is that every dead man becomes
a demon, who is often somewhere at hand, may at any moment return, may
give aid or do mischief, and has to be continually propitiated. Hence
among other agents whose approbation or reprobation are contemplated by
the savage as consequences of his conduct, are the spirits of his
ancestors. When a child he is told of their deeds, now in triumphant
tones, now in whispers of horror; and the instilled belief that they may
inflict some vaguely-imagined but fearful evil, or give some great help,
becomes a powerful incentive or deterrent. Especially does this happen
when the story is of a chief, distinguished for his strength, his
ferocity, his persistence in that revenge on enemies which the
experiences of the savage make him regard as beneficial and virtuous.
The consciousness that such a chief, dreaded by neighbouring tribes, and
dreaded, too, by members of his own tribe, may reappear and punish those
who have disregarded his injunctions, becomes a powerful motive. But it
is clear, in the first place, that the imagined anger and the imagined
satisfaction of this deified chief, are simply transfigured forms of the
anger and satisfaction displayed by those around; and that the feelings
accompanying such imaginations have the same original root in the
experiences which have associated an average of painful results with the
manifestation of another's anger, and an average of pleasurable results
with the manifestation of another's satisfaction. And it is clear, in
the second place, that the actions thus forbidden and encouraged must be
mostly actions that are respectively detrimental and beneficial to the
tribe; since the successful chief is usually a better judge than the
rest, and has the preservation of the tribe at heart. Hence experiences
of utility, consciously or unconsciously organized, underlie his
injunctions; and the sentiments which prompt obedience are, though very
indirectly and without the knowledge of those who feel them, referable
to experiences of utility.

This transfigured form of restraint, differing at first but little from
the original form, admits of immense development. Accumulating
traditions, growing in grandeur as they are repeated from generation to
generation, make more and more superhuman the early-recorded hero of the
race. His powers of inflicting punishment and giving happiness become
ever greater, more multitudinous, and more varied; so that the dread of
divine displeasure, and the desire to obtain divine approbation, acquire
a certain largeness and generality. Still the conceptions remain
anthropomorphic. The revengeful deity continues to be thought of in
terms of human emotions, and continues to be represented as displaying
these emotions in human ways. Moreover, the sentiments of right and
duty, so far as they have become developed, refer mainly to divine
commands and interdicts; and have little reference to the natures of the
acts commanded or interdicted. In the intended offering-up of Isaac, in
the sacrifice of Jephthah's daughter, and in the hewing to pieces of
Agag, as much as in the countless atrocities committed from religious
motives by various early historic races, as by some existing savage
races, we see that the morality and immorality of actions, as we
understand them, are at first little recognized; and that the feelings,
chiefly of dread, which serve in place of them, are feelings felt
towards the unseen beings supposed to issue the commands and interdicts.

Here it will be said that, as just admitted, these are not the moral
sentiments properly so called. They are simply sentiments that precede
and make possible those highest sentiments which do not refer either to
personal benefits or evils to be expected from men, or to more remote
rewards and punishments. Several comments are, however, called forth by
this criticism. One is, that if we glance back at past beliefs and their
correlative feelings, as shown in Dante's poem, in the mystery-plays of
the middle ages, in St. Bartholomew massacres, in burnings for heresy,
we get proof that in comparatively modern times right and wrong meant
little else than subordination or insubordination--to a divine ruler
primarily, and under him to a human ruler. Another is, that down to our
own day this conception largely prevails, and is even embodied in
elaborate ethical works--instance the _Essays on the Principles of
Morality_, by Jonathan Dymond, which recognizes no ground of moral
obligation save the will of God as expressed in the current creed. And
yet a further is, that while in sermons the torments of the damned and
the joys of the blessed are set forth as the dominant deterrents and
incentives, and while we have prepared for us printed instructions "how
to make the best of both worlds," it cannot be denied that the feelings
which impel and restrain men are still largely composed of elements like
those operative on the savage: the dread, partly vague, partly specific,
associated with the idea of reprobation, human and divine, and the sense
of satisfaction, partly vague, partly specific, associated with the idea
of approbation, human and divine.

But during the growth of that civilization which has been made possible
by these ego-altruistic sentiments, there have been slowly evolving the
altruistic sentiments. Development of these has gone on only as fast as
society has advanced to a state in which the activities are mainly
peaceful. The root of all the altruistic sentiments is sympathy; and
sympathy could become dominant only when the mode of life, instead of
being one that habitually inflicted direct pain, became one which
conferred direct and indirect benefits: the pains inflicted being mainly
incidental and indirect. Adam Smith made a large step towards this truth
when he recognized sympathy as giving rise to these superior controlling
emotions. His _Theory of Moral Sentiments_, however, requires to be
supplemented in two ways. The natural process by which sympathy becomes
developed into a more and more important element of human nature has to
be explained; and there has also to be explained the process by which
sympathy produces the highest and most complex of the altruistic
sentiments--that of justice. Respecting the first process, I can here do
no more than say that sympathy may be proved, both inductively and
deductively, to be the concomitant of gregariousness: the two having all
along-increased by reciprocal aid. Multiplication has ever tended to
force into an association, more or less close, all creatures having
kinds of food and supplies of food that permit association; and
established psychological laws warrant the inference that some sympathy
will inevitably result from habitual manifestations of feelings in
presence of one another, and that the gregariousness being augmented by
the increase of sympathy, further facilitates the development of
sympathy. But there are negative and positive checks upon this
development--negative, because sympathy cannot advance faster than
intelligence advances, since it presupposes the power of interpreting
the natural language of the various feelings, and of mentally
representing those feelings; positive, because the immediate needs of
self-preservation are often at variance with its promptings, as, for
example, during the predatory stages of human progress. For explanations
of the second process, I must refer to the _Principles of Psychology_ (§
202, first edition, and § 215, second edition) and to _Social Statics_,
part ii. chapter v.[36] Asking that in default of space these
explanations may be taken for granted, let me here point out in what
sense even sympathy, and the sentiments that result from it, are due to
experiences of utility. If we suppose all thought of rewards or
punishments, immediate or remote, to be left out of consideration, it is
clear that any one who hesitates to inflict a pain because of the vivid
representation of that pain which rises in his consciousness, is
restrained, not by any sense of obligation or by any formulated doctrine
of utility, but by the painful association established in him. And it is
clear that if, after repeated experiences of the moral discomfort he has
felt from witnessing the unhappiness indirectly caused by some of his
acts, he is led to check himself when again tempted to those acts, the
restraint is of like nature. Conversely with the pleasure-giving acts:
repetitions of kind deeds, and experiences of the sympathetic
gratifications that follow, tend continually to make stronger the
association between such deeds and feelings of happiness.

Eventually these experiences may be consciously generalized, and there
may result a deliberate pursuit of sympathetic gratifications. There may
also come to be distinctly recognized the truths that the remoter
results, kind and unkind conduct, are respectively beneficial and
detrimental--that due regard for others is conducive to ultimate
personal welfare, and disregard of others to ultimate personal disaster;
and then there may become current such summations of experience as
"honesty is the best policy." But so far from regarding these
intellectual recognitions of utility as preceding and causing the moral
sentiment, I regard the moral sentiment as preceding such recognitions
of utility, and making them possible. The pleasures and pains directly
resulting in experience from sympathetic and unsympathetic actions, had
first to be slowly associated with such actions, and the resulting
incentives and deterrents frequently obeyed, before there could arise
the perceptions that sympathetic and unsympathetic actions are remotely
beneficial or detrimental to the actor; and they had to be obeyed still
longer and more generally before there could arise the perceptions that
they are socially beneficial or detrimental. When, however, the remote
effects, personal and social, have gained general recognition, are
expressed in current maxims, and lead to injunctions having the
religious sanction, the sentiments that prompt sympathetic actions and
check unsympathetic ones are immensely strengthened by their alliances.
Approbation and reprobation, divine and human, come to be associated in
thought with the sympathetic and unsympathetic actions respectively. The
commands of the creed, the legal penalties, and the code of social
conduct, unitedly enforce them; and every child as it grows up, daily
has impressed on it by the words and faces and voices of those around
the authority of these highest principles of conduct. And now we may see
why there arises a belief in the special sacredness of these highest
principles, and a sense of the supreme authority of the altruistic
sentiments answering to them. Many of the actions which, in early social
states, received the religious sanction and gained public approbation,
had the drawback that such sympathies as existed were outraged, and
there was hence an imperfect satisfaction. Whereas these altruistic
actions, while similarly having the religious sanction and gaining
public approbation, bring a sympathetic consciousness of pleasure given
or of pain prevented; and, beyond this, bring a sympathetic
consciousness of human welfare at large, as being furthered by making
altruistic actions habitual. Both this special and this general
sympathetic consciousness become stronger and wider in proportion as the
power of mental representation increases, and the imagination of
consequences, immediate and remote, grows more vivid and comprehensive.
Until at length these altruistic sentiments begin to call in question
the authority of those ego-altruistic sentiments which once ruled
unchallenged. They prompt resistance to laws that do not fulfil the
conception of justice, encourage men to brave the frowns of their
fellows by pursuing a course at variance with customs that are perceived
to be socially injurious, and even cause dissent from the current
religion; either to the extent of disbelief in those alleged divine
attributes and acts not approved by this supreme moral arbiter, or to
the extent of entire rejection of a creed which ascribes such attributes
and acts.

Much that is required to make this hypothesis complete must stand over
until, at the close of the second volume of the _Principles of
Psychology_, I have space for a full exposition. What I have said will
make it sufficiently clear that two fundamental errors have been made in
the interpretation put upon it. Both Utility and Experience have been
construed in senses much too narrow. Utility, convenient a word as it is
from its comprehensiveness, has very inconvenient and misleading
implications. It vividly suggests uses, and means, and proximate ends,
but very faintly suggests the pleasures, positive or negative, which are
the ultimate ends, and which, in the ethical meaning of the word, are
alone considered; and, further, it implies conscious recognition of
means and ends--implies the deliberate taking of some course to gain a
perceived benefit. Experience, too, in its ordinary acceptation,
connotes definite perceptions of causes and consequences, as standing in
observed relations, and is not taken to include the connexions formed in
consciousness between states that recur together, when the relation
between them, causal or other, is not perceived. It is in their widest
senses, however, that I habitually use these words, as will be manifest
to every one who reads the _Principles of Psychology;_ and it is in
their widest senses that I have used them in the letter to Mr. Mill. I
think I have shown above that, when they are so understood, the
hypothesis briefly set forth in that letter is by no means so
indefensible as is supposed. At any rate, I have shown--what seemed for
the present needful to show--that Mr. Hutton's versions of my views must
not be accepted as correct.

FOOTNOTES:

[Footnote 33: See _Prospective Review_ for January, 1852.]

[Footnote 34: His criticism will be found in the _National Review_ for
January, 1856, under the title "Atheism."]

[Footnote 35: Hereafter I hope to elucidate at length these phenomena of
expression. For the present, I can refer only to such further
indications as are contained in two essays on "The Physiology of
Laughter" and "The Origin and Function of Music."]

[Footnote 36: I may add that in _Social Statics_, chap. xxx., I have
indicated, in a general way, the causes of the development of sympathy
and the restraints upon its development--confining the discussion,
however, to the case of the human race, my subject limiting me to that.
The accompanying teleology I now disclaim.]




THE COMPARATIVE PSYCHOLOGY OF MAN.

    [_Originally read before the Anthropological Institute, and
    afterwards published in _Mind, _for January,_ 1876.]


While discussing with two members of the Anthropological Institute the
work to be undertaken by its psychological section, I made certain
suggestions which they requested me to put in writing. When reminded,
some months after, of the promise I had made to do this, I failed to
recall the particular suggestions referred to; but in the endeavour to
remember them, I was led to glance over the whole subject of comparative
human psychology. Hence resulted the following paper.

That making a general survey is useful as a preliminary to deliberate
study, either of a whole or of any part, scarcely needs showing.
Vagueness of thought accompanies the wandering about in a region without
known bounds or landmarks. Attention devoted to some portion of a
subject in ignorance of its connexion with the rest, leads to untrue
conceptions. The whole cannot be rightly conceived without some
knowledge of the parts; and no part can be rightly conceived out of
relation to the whole.

To map out the Comparative Psychology of Man must also conduce to the
more methodic carrying on of inquiries. In this, as in other things,
division of labour will facilitate progress; and that there may be
division of labour, the work itself must be systematically divided.

We may conveniently separate the entire subject into three main
divisions, and may arrange them in the order of increasing speciality.

The first division will treat of the degrees of mental evolution of
different human types, generally considered: taking account of both the
mass of mental manifestation and the complexity of mental manifestation.
This division will include the relations of these characters to physical
characters--the bodily mass and structure, and the cerebral mass and
structure. It will also include inquiries concerning the time taken in
completing mental evolution, and the time during which adult mental
power lasts; as well as certain most general traits of mental action,
such as the greater or less persistence of emotions and of intellectual
processes. The connexion between the general mental type and the general
social type should also be here dealt with.

In the second division may be conveniently placed apart, inquiries
concerning the relative mental natures of the sexes in each race. Under
it will come such questions as these:--What differences of mental mass
and mental complexity, if any, existing between males and females, are
common to all races? Do such differences vary in degree, or in kind, or
in both? Are there reasons for thinking that they are liable to change
by increase or decrease? What relations do they bear in each case to the
habits of life, the domestic arrangements, and the social arrangements?
This division should also include in its scope the sentiments of the
sexes towards one another, considered as varying quantitatively and
qualitatively; as well as their respective sentiments towards offspring,
similarly varying.

For the third division of inquiries may be reserved the more special
mental traits distinguishing different types of men. One class of such
specialities results from differences of proportion among faculties
possessed in common; and another class results from the presence in some
races of faculties that are almost or quite absent from others. Each
difference in each of these groups, when established by comparison, has
to be studied in connexion with the stage of mental evolution reached,
and has to be studied in connexion with the habits of life and the
social development, regarding it as related to these both as cause and
as consequence.

Such being the outlines of these several divisions, let us now consider
in detail the subdivisions contained within each.

       *       *       *       *       *

I.--Under the head of general mental evolution we may begin with the
trait of--

1. _Mental mass._--Daily experiences show us that human beings differ in
volume of mental manifestation. Some there are whose intelligence, high
though it may be, produces little impression on those around; while
there are some who, when uttering even commonplaces, do it so as to
affect listeners in a disproportionate degree. Comparison of two such,
makes it manifest that, generally, the difference is due to the natural
language of the emotions. Behind the intellectual quickness of the one
there is not felt any power of character; while the other betrays a
momentum capable of bearing down opposition--a potentiality of emotion
that has something formidable about it. Obviously the varieties of
mankind differ much in respect of this trait. Apart from kind of
feeling, they are unlike in amount of feeling. The dominant races
overrun the inferior races mainly in virtue of the greater quantity of
energy in which this greater mental mass shows itself. Hence a series of
inquiries, of which these are some:--(_a_) What is the relation between
mental mass and bodily mass? Manifestly, the small races are deficient
in it. But it also appears that races much upon a par in size--as, for
instance, an Englishman and a Damara, differ considerably in mental
mass. (_b_) What is its relation to mass of brain? and, bearing in mind
the general law that in the same species, size of brain increases with
size of body (though not in the same proportion), how far can we connect
the extra mental mass of the higher races, with an extra mass of brain
beyond that which is proper to their greater bodily mass? (_c_) What
relation, if any, is there between mental mass and the physiological
state expressed in vigour of circulation and richness of blood, as
severally determined by mode of life and general nutrition? (_d_) What
are the relations of this trait to the social state, as nomadic or
settled, predatory or industrial?

2. _Mental complexity._--How races differ in respect of the more or less
involved structures of their minds, will best be understood on recalling
the unlikeness between the juvenile mind and the adult mind among
ourselves. In the child we see absorption in special facts. Generalities
even of a low order are scarcely recognized, and there is no recognition
of high generalities. We see interest in individuals, in personal
adventures, in domestic affairs, but no interest in political or social
matters. We see vanity about clothes and small achievements, but little
sense of justice: witness the forcible appropriation of one another's
toys. While there have come into play many of the simpler mental powers,
there has not yet been reached that complication of mind which results
from the addition of powers evolved out of these simpler ones. Kindred
differences of complexity exist between the minds of lower and higher
races; and comparisons should be made to ascertain their kinds and
amounts. Here, too, there may be a subdivision of the inquiries. (_a_)
What is the relation between mental complexity and mental mass? Do not
the two habitually vary together? (_b_) What is the relation to the
social state, as more or less complex? that is to say--Do not mental
complexity and social complexity act and react on each other?

3. _Rate of mental development._--In conformity with the biological law
that the higher the organisms the longer they take to evolve, members of
the inferior human races may be expected to complete their mental
evolution sooner than members of the superior races; and we have
evidence that they do this. Travellers from many regions comment, now on
the great precocity of children among savage and semi-civilized peoples,
and now on the early arrest of their mental progress. Though we scarcely
need more proofs that this general contrast exists, there remains to be
asked the question, whether it is consistently maintained throughout all
groups of races, from the lowest to the highest--whether, say, the
Australian differs in this respect from the Hindu, as much as the Hindu
does from the European. Of secondary inquiries coming under this
sub-head may be named several. (_a_) Is this more rapid evolution and
earlier arrest always unequally shown by the two sexes; or, in other
words, are there in lower types proportional differences in rate and
degree of development, such as higher types show us? (_b_) Is there in
many cases, as there appears to be in some cases, a traceable relation
between the period of arrest and the period of puberty? (_c_) Is mental
decay early in proportion as mental evolution is rapid? (_d_) Can we in
other respects assert that where the type is low, the entire cycle of
mental changes between birth and death--ascending, uniform,
descending--comes within a shorter interval?

4. _Relative plasticity._--Is there any relation between the degree of
mental modifiability which remains in adult life, and the character of
the mental evolution in respect of mass, complexity, and rapidity? The
animal kingdom at large yields reasons for associating an inferior and
more rapidly-completed mental structure, with a relatively automatic
nature. Lowly organized creatures, guided almost entirely by reflex
actions, are in but small degrees changeable by individual experiences.
As the nervous structure complicates, its actions become less rigorously
confined within pre-established limits; and as we approach the highest
creatures, individual experiences take larger and larger shares in
moulding the conduct: there is an increasing ability to take in new
impressions and to profit by the acquisitions. Inferior and superior
human races are contrasted in this respect. Many travellers comment on
the unchangeable habits of savages. The semi-civilized nations of the
East, past and present, were, or are, characterized by a greater
rigidity of custom than characterizes the more civilized nations of the
West. The histories of the most civilized nations show us that in their
earlier times, the modifiability of ideas and habits was less than it is
at present. And if we contrast classes or individuals around us, we see
that the most developed in mind are the most plastic. To inquiries
respecting this trait of comparative plasticity, in its relations to
precocity and early completion of mental development, may fitly be added
inquiries respecting its relations to the social state, which it helps
to determine, and which reacts upon it.

5. _Variability._--To say of a mind that its actions are extremely
inconstant, and at the same time to say that it is of relatively
unchangeable nature, apparently implies a contradiction. When, however,
the inconstancy is understood as referring to the manifestations which
follow one another from minute to minute, and the unchangeableness to
the average manifestations, extending over long periods, the apparent
contradiction disappears; and it becomes comprehensible that the two
traits may, and ordinarily do, co-exist. An infant, quickly wearied with
each kind of perception, wanting ever a new object which it soon
abandons for something else, and alternating a score times a day between
smiles and tears, shows us a very small persistence in each kind of
mental action: all its states, intellectual and emotional, are
transient. Yet at the same time its mind cannot be easily changed in
character. True, it changes spontaneously in due course; but it long
remains incapable of receiving ideas or emotions beyond those of simple
orders. The child exhibits less rapid variations, intellectual and
emotional, while its educability is greater. Inferior human races show
us this combination: great rigidity of general character with great
irregularity in its passing manifestations. Speaking broadly, while they
resist permanent modification, they lack intellectual persistence, and
they lack emotional persistence. Of various low types we read that they
cannot keep the attention fixed beyond a few minutes on anything
requiring thought, even of a simple kind. Similarly with their feelings:
these are less enduring than those of civilized men. There are, however,
qualifications to be made in this statement; and comparisons are needed
to ascertain how far these qualifications go. The savage shows great
persistence in the action of the lower intellectual faculties. He is
untiring in minute observation. He is untiring, also, in that kind of
perceptive activity which accompanies the making of his weapons and
ornaments: often persevering for immense periods in carving stones, &c.
Emotionally, too, he shows persistence not only in the motives prompting
these small industries, but also in certain of his passions--especially
in that of revenge. Hence, in studying the degrees of mental variability
shown us in the daily lives of the different races, we must ask how far
variability characterizes the whole mind, and how far it holds only of
parts of the mind.

6. _Impulsiveness._--This trait is closely allied with the last:
unenduring emotions are emotions which sway the conduct now this way and
now that, without any consistency. The trait of impulsiveness may,
however, be fitly dealt with separately, because it has other
implications than mere lack of persistence. Comparisons of the lower
human races with the higher, appear generally to show that, along with
brevity of the passions, there goes violence. The sudden gusts of
feeling which men of inferior types display, are excessive in degree as
they are short in duration; and there is probably a connexion between
these two traits: intensity sooner producing exhaustion. Observing that
the passions of childhood illustrate this connexion, let us turn to
certain interesting questions concerning the decrease of impulsiveness
which accompanies advance in evolution. The nervous processes of an
impulsive being, are less remote from reflex actions than are those of
an unimpulsive being. In reflex actions we see a simple stimulus passing
suddenly into movement: little or no control being exercised by other
parts of the nervous system. As we ascend to higher actions, guided by
more and more complicated combinations of stimuli, there is not the same
instantaneous discharge in simple motions; but there is a comparatively
deliberate and more variable adjustment of compound motions, duly
restrained and proportioned. It is thus with the passions and sentiments
in the less developed natures and in the more developed natures. Where
there is but little emotional complexity, an emotion, when excited by
some occurrence, explodes in action before the other emotions have been
called into play; and each of these, from time to time, does the like.
But the more complex emotional structure is one in which these simpler
emotions are so co-ordinated that they do not act independently. Before
excitement of any one has had time to cause action, some excitement has
been communicated to others--often antagonistic ones; and the conduct
becomes modified in adjustment to the combined dictates. Hence results a
decreased impulsiveness, and also a greater persistence. The conduct
pursued, being prompted by several emotions co-operating in degrees
which do not exhaust them, acquires a greater continuity; and while
spasmodic force becomes less conspicuous, there is an increase in the
total energy. Examining the facts from this point of view, there are
sundry questions of interest to be put respecting the different races of
men. (_a_) To what other traits than degree of mental evolution is
impulsiveness related? Apart from difference in elevation of type, the
New-World races seem to be less impulsive than the Old-World races. Is
this due to constitutional apathy? Can there be traced (other things
equal) a relation between physical vivacity and mental impulsiveness?
(_b_) What connexion is there between this trait and the social state?
Clearly a very explosive nature--such as that of the Bushman--is unfit
for social union; and, commonly, social union, when by any means
established, checks impulsiveness. (_c_) What respective shares in
checking impulsiveness are taken by the feelings which the social state
fosters--such as the fear of surrounding individuals, the instinct of
sociality, the desire to accumulate property, the sympathetic feelings,
the sentiment of justice? These, which require a social environment for
their development, all of them involve imaginations of consequences more
or less distant; and thus imply checks upon the promptings of the
simpler passions. Hence arise the questions--In what order, in what
degrees, and in what combinations, do they come into play?

7. One further general inquiry of a different kind may be added. What
effect is produced on mental nature by mixture of races? There is reason
for believing that throughout the animal kingdom, the union of varieties
which have become widely divergent is physically injurious; while the
union of slightly divergent varieties is physically beneficial. Does the
like hold with the mental nature? Some facts seem to show that mixture
of human races extremely unlike, produces a worthless type of mind--a
mind fitted neither for the kind of life led by the higher of the two
races, nor for that led by the lower--a mind out of adjustment to all
conditions of life. Contrariwise, we find that peoples of the same
stock, slightly differentiated by lives carried on in unlike
circumstances for many generations, produce by mixture a mental type
having certain superiorities. In his work on _The Huguenots_, Mr. Smiles
points out how large a number of distinguished men among us have
descended from Flemish and French refugees; and M. Alphonse de Candolle,
in his _Histoire des Sciences et des Savants depuis deux Siècles_, shows
that the descendants of French refugees in Switzerland have produced an
unusually great proportion of scientific men. Though, in part, this
result may be ascribed to the original natures of such refugees, who
must have had that independence which is a chief factor in originality,
yet it is probably in part due to mixtures of races. For thinking this,
we have evidence which is not open to two interpretations. Prof. Morley
draws attention to the fact that, during seven hundred years of our
early history "the best genius of England sprang up on the line of
country in which Celts and Anglo-Saxons came together." In like manner
Mr. Galton, in his _English Men of Science_, shows that in recent days
these have mostly come from an inland region, running generally from
north to south, which we may reasonably presume contains more mixed
blood than do the regions east and west of it. Such a result seems
probable _a priori_. Two natures respectively adapted to slightly unlike
sets of social conditions, may be expected by their union to produce a
nature somewhat more plastic than either--a nature more impressible by
the new circumstances of advancing social life, and therefore more
likely to originate new ideas and display modified sentiments. The
Comparative Psychology of Man may, then, fitly include the mental
effects of mixture; and among derivative inquiries we may ask--How far
the conquest of race by race has been instrumental in advancing
civilization by aiding mixture, as well as in other ways.


II.--The second of the three leading divisions named at the outset is
less extensive. Still, concerning the relative mental natures of the
sexes in each race, questions of much interest and importance may be
raised.

1. _Degree of difference between the sexes._--It is an established fact
that, physically considered, the contrast between males and females is
not equally great in all types of mankind. The bearded races, for
instance, show us a greater unlikeness between the two than do the
beardless races. Among South American tribes, men and women have a
greater general resemblance in form, &c., than is usual elsewhere. The
question, then, suggests itself--Do the mental natures of the sexes
differ in a constant or in a variable degree? The difference is unlikely
to be a constant one; and, looking for variation, we may ask what is its
amount, and under what conditions does it occur?

2. _Difference in mass and in complexity._--The comparisons between the
sexes, of course, admit of subdivisions parallel to those made in the
comparisons between races. Relative mental mass and relative mental
complexity have chiefly to be observed. Assuming that the great
inequality in the cost of reproduction to the two sexes, is the cause of
unlikeness in mental mass, as in physical mass, this difference may be
studied in connexion with reproductive differences presented by the
various races, in respect of the ages at which reproduction commences,
and the periods over which it lasts. An allied inquiry may be joined
with this; namely, how far the mental developments of the two sexes are
affected by their relative habits in respect to food and physical
exertion? In many of the lower races, the women, treated with great
brutality, are, physically, much inferior to the men: excess of labour
and defect of nutrition being apparently the combined causes. Is any
arrest of mental development simultaneously caused?

3. _Variation of the differences._--If the unlikeness, physical and
mental, of the sexes is not constant, then, supposing all races have
diverged from one original stock, it follows that there must have been
transmission of accumulated differences to those of the same sex in
posterity. If, for instance, the prehistoric type of man was beardless,
then the production of a bearded variety implies that within that
variety the males continued to transmit an increasing amount of beard to
descendants of the same sex. This limitation of heredity by sex, shown
us in multitudinous ways throughout the animal kingdom, probably applies
to the cerebral structures as much as to other structures. Hence the
question--Do not the mental natures of the sexes in alien types of Man
diverge in unlike ways and degrees?

4. _Causes of the differences._--Are any relations to be traced between
these variable differences and the variable parts the sexes play in the
business of life? Assuming the cumulative effects of habit on function
and structure, as well as the limitation of heredity by sex, it is to be
expected that if, in any society, the activities of one sex, generation
after generation, differ from those of the other, there will arise
sexual adaptations of mind. Some instances in illustration may be named.
Among the Africans of Loango and other districts, as also among some of
the Indian Hill-tribes, the men and women are strongly contrasted as
respectively inert and energetic: the industry of the women having
apparently become so natural to them that no coercion is needed. Of
course, such facts suggest an extensive series of questions. Limitation
of heredity by sex may account both for those sexual differences of mind
which distinguish men and women in all races, and for those which
distinguish them in each race, or each society. An interesting
subordinate inquiry may be, how far such mental differences are inverted
in cases where there is inversion of social and domestic relations; as
among those Khasi Hill-tribes, whose women have so far the upper hand
that they turn off their husbands in a summary way if they displease
them.

5. _Mental modifiability in the two sexes._--Along with comparisons of
races in respect of mental plasticity may go parallel comparisons of the
sexes in each race. Is it true always, as it appears to be generally
true, that women are less modifiable than men? The relative conservatism
of women--their greater adhesion to established ideas and practices--is
manifest in many civilized and semi-civilized societies. Is it so among
the uncivilized? A curious instance of stronger attachment to custom in
women than in men is given by Dalton, as occurring among the Juangs, one
of the lowest wild tribes of Bengal. Until recently the only dress of
both sexes was something less than that which the Hebrew legend gives to
Adam and Eve. Years ago the men were led to adopt a cloth bandage round
the loins, in place of the bunch of leaves; but the women adhered to the
aboriginal habit: a conservatism shown where it might have been least
expected.

6. _The sexual sentiment._--Results of value may be looked for from
comparisons of races made to determine the amounts and characters of the
higher feelings to which the relation of the sexes gives rise. The
lowest varieties of mankind have but small endowments of these feelings.
Among varieties of higher types, such as the Malayo-Polynesians, these
feelings seem considerably developed: the Dyaks, for instance, sometimes
display them in great strength. Speaking generally, they appear to
become stronger with the advance of civilization. Several subordinate
inquiries may be named. (_a_) How far is development of the sexual
sentiment dependent upon intellectual advance--upon growth of
imaginative power? (_b_) How far is it related to emotional advance; and
especially to evolution of those emotions which originate from sympathy?
What are its relations to polyandry and polygyny? (_c_) Does it not
tend towards, and is it not fostered by, monogamy? (_d_) What connexion
has it with maintenance of the family bond, and the consequent better
rearing of children?


III.--Under the third head, to which we may now pass come the more
special traits of the different races.

1. _Imitativeness._--One of the characteristics in which the lower types
of men show us a smaller departure from reflex action than do the higher
types, is their strong tendency to mimic the motions and sounds made by
others--an almost involuntary habit which travellers find it difficult
to check. This meaningless repetition, which seems to imply that the
idea of an observed action cannot be framed in the mind of the observer
without tending forthwith to discharge itself in the action conceived
(and every ideal action is a nascent form of the consciousness
accompanying performance of such action), evidently diverges but little
from the automatic; and decrease of it is to be expected along with
increase of self-regulating power. This trait of automatic mimicry is
evidently allied with that less automatic mimicry which shows itself in
greater persistence of customs. For customs adopted by each generation
from the last without thought or inquiry, imply a tendency to imitate
which overmasters critical and sceptical tendencies: so maintaining
habits for which no reasons can be given. The decrease of this
irrational mimicry, strongest in the lowest savage and feeblest in the
highest of the civilized, should be studied along with the successively
higher stages of social life, as being at once an aid and a hindrance to
civilization: an aid in so far as it gives that fixity to the social
organization without which a society cannot survive; a hindrance in so
far as it offers resistance to changes of social organization that have
become desirable.

2. _Incuriosity._--Projecting our own natures into the circumstances of
the savage, we imagine ourselves as marvelling greatly on first seeing
the products and appliances of civilized life. But we err in supposing
that the savage has feelings such as we should have in his place. Want
of rational curiosity respecting these incomprehensible novelties, is a
trait remarked of the lowest races wherever found; and the
partially-civilized races are distinguished from them as exhibiting
rational curiosity. The relation of this trait to the intellectual
nature, to the emotional nature, and to the social state, should be
studied.

3. _Quality of thought._--Under this vague head may be placed many sets
of inquiries, each of them extensive--(_a_) The degree of generality of
the ideas; (_b_) the degree of abstractness of the ideas; (_c_) the
degree of definiteness of the ideas; (_d_) the degree of coherence of
the ideas; (_e_) the extent to which there have been developed such
notions as those of _class_, of _cause_, of _uniformity_, of _law_, of
_truth_. Many conceptions which have become so familiar to us that we
assume them to be the common property of all minds, are no more
possessed by the lowest savages than they are by our own children; and
comparisons of types should be so made as to elucidate the processes by
which such conceptions are reached. The development under each head has
to be observed--(_a_) independently in its successive stages; (_b_) in
connexion with the co-operative intellectual conceptions; (_c_) in
connexion with the progress of language, of the arts, and of social
organization. Already linguistic phenomena have been used in aid of such
inquiries; and more systematic use of them should be made. Not only the
number of general words, and the number of abstract words, in a people's
vocabulary should be taken as evidence, but also their _degrees_ of
generality and abstractness; for there are generalities of the first,
second, third, &c., orders, and abstractions similarly ascending. _Blue_
is an abstraction referring to one class of impressions derived from
visible objects; _colour_ is a higher abstraction referring to many such
classes of visual impressions; _property_ is a still higher
abstraction referring to classes of impressions received not through the
eyes alone, but through other sense-organs. If generalities and
abstractions were arranged in the order of their extensiveness and in
the order of their grades, tests would be obtained which, applied to the
vocabularies of the uncivilized, would yield definite evidence of the
intellectual stages reached.

4. _Peculiar aptitudes._--To such specialities of intelligence as mark
different degrees of evolution, have to be added minor ones related to
modes of life: the kinds and degrees of faculty which have become
organized in adaptation to daily habits--skill in the use of weapons,
powers of tracking, quick discrimination of individual objects. And
under this head may fitly come inquiries concerning some
race-peculiarities of the æsthetic class, not at present explicable.
While the remains from the Dordogne caves show us that their
inhabitants, low as we must suppose them to have been, could represent
animals, both by drawing and carving, with some degree of fidelity;
there are existing races, probably higher in other respects, who seem
scarcely capable of recognizing pictorial representations. Similarly
with the musical faculty. Almost or quite wanting in some inferior
races, we find it in other races not of high grade, developed to an
unexpected degree: instance the Negroes, some of whom are so innately
musical, that, as I have been told by a missionary among them, the
children in native schools when taught European psalm-tunes,
spontaneously sing seconds to them. Whether any causes can be discovered
for race peculiarities of this kind, is a question of interest.

5. _Specialities of emotional nature._--These are worthy of careful
study, as being intimately related to social phenomena--to the
possibility of social progress, and to the nature of the social
structure. Among others to be noted there are--(_a_) Gregariousness or
sociality--a trait in the strength of which races differ widely: some,
as the Mantras, being almost indifferent to social intercourse; some
being unable to dispense with it. Obviously the degree of this desire
for the presence of fellow-men, affects greatly the formation of social
groups, and consequently influences social progress. (_b_) Intolerance
of restraint. Men of some inferior types, as the Mapuché, are
ungovernable; while those of other types, no higher in grade, not only
submit to restraint, but admire the persons exercising it. These
contrasted natures have to be observed in connexion with social
evolution; to the early stages of which they are respectively
antagonistic and favourable. (_c_) The desire for praise is a trait
which, common to all races, high and low, varies considerably in degree.
There are quite inferior races, as some of those in the Pacific States,
whose members sacrifice without stint to gain the applause which lavish
generosity brings; while, elsewhere, applause is sought with less
eagerness. Notice should be taken of the connexion between this love of
approbation and the social restraints; since it plays an important part
in the maintenance of them. (_d_) The acquisitive propensity. This, too,
is a character the degrees of which, and the relations of which to the
social state, have to be especially noted. The desire for property grows
along with the possibility of gratifying it; and this, extremely small
among the lowest men, increases as social development goes on. With the
advance from tribal property to family property and individual property,
the notion of private right of possession gains definiteness, and the
love of acquisition strengthens. Each step towards an orderly social
state makes larger accumulations possible, and the pleasures achievable
by them more sure; while the resulting encouragement to accumulate,
leads to increase of capital and to further progress. This action and
re-action of the sentiment and the social state, should be in every case
observed.

6. _The altruistic sentiments._--Coming last, these are also highest.
The evolution of them in the course of civilization, shows us clearly
the reciprocal influences of the social unit and the social organism. On
the one hand, there can be no sympathy, nor any of the sentiments which
sympathy generates, unless there are fellow-beings around. On the other
hand, maintenance of union with fellow-beings depends in part on the
presence of sympathy, and the resulting restraints on conduct.
Gregariousness or sociality favours the growth of sympathy; increased
sympathy conduces to closer sociality and a more stable social state;
and so, continuously, each increment of the one makes possible a further
increment of the other. Comparisons of the altruistic sentiments
resulting from sympathy, as exhibited in different types of men and
different social states, may be conveniently arranged under three
heads--(_a_) Pity, which should be observed as displayed towards
offspring, towards the sick and aged, and towards enemies. (_b_)
Generosity (duly discriminated from the love of display) as shown in
giving; as shown in the relinquishment of pleasures for the sake of
others; as shown by active efforts on others' behalf. The manifestations
of this sentiment, too, are to be noted in respect of their
range--whether they are limited to relatives; whether they extend only
to those of the same society; whether they extend to those of other
societies; and they are also to be noted in connexion with the degree of
providence--whether they result from sudden impulses obeyed without
counting the cost, or go along with clear foresight of the future
sacrifices entailed. (_c_) Justice. This most abstract of the altruistic
sentiments is to be considered under aspects like those just named, as
well as under many other aspects--how far it is shown in regard to the
lives of others; how far in regard to their freedom; how far in regard
to their property; how far in regard to their various minor claims. And
comparisons concerning this highest sentiment should, beyond all others,
be carried on along with comparisons of the accompanying social
states, which it largely determines--the forms and actions of
governments; the characters of laws; the relations of classes.

       *       *       *       *       *

Such, stated as briefly as consists with clearness, are the leading
divisions and subdivisions under which the Comparative Psychology of Man
may be arranged. In going rapidly over so wide a field, I have doubtless
overlooked much that should be included. Doubtless, too, various of the
inquiries named will branch out into subordinate inquiries well worth
pursuing. Even as it is, however, the programme is extensive enough to
occupy numerous investigators, who may with advantage take separate
divisions.

Though, after occupying themselves with primitive arts and products,
anthropologists have devoted their attention mainly to the physical
characters of the human races; it must, I think, be admitted that the
study of these yields in importance to the study of their psychical
characters. The general conclusions to which the first set of inquiries
may lead, cannot so much affect our views respecting the highest classes
of phenomena as can the general conclusions to which the second set may
lead. A true theory of the human mind vitally concerns us; and
systematic comparisons of human minds, differing in their kinds and
grades, will help us in forming a true theory. Knowledge of the
reciprocal relations between the characters of men and the characters of
the societies they form, must influence profoundly our ideas of
political arrangements. When the inter-dependence of individual natures
and social structures is understood, our conceptions of the changes now
taking place, and hereafter to take place, will be rectified. A
comprehension of mental development as a process of adaptation to social
conditions, which are continually remoulding the mind and are again
remoulded by it, will conduce to a salutary consciousness of the
remoter effects produced by institutions upon character; and will
check the grave mischiefs which ignorant legislation now causes. Lastly,
a right theory of mental evolution as exhibited by humanity at large,
giving a key, as it does, to the evolution of the individual mind, must
help to rationalize our perverse methods of education; and so to raise
intellectual power and moral nature.




MR. MARTINEAU ON EVOLUTION.

    [_First published in _The Contemporary Review_, for June,_ 1872.]


The article by Mr. Martineau, in the April number of the _Contemporary
Review_, on "The Place of Mind in Nature, and Intuition of Man,"
recalled to me a partially-formed intention to deal with the chief
criticisms which have from time to time been made on the general
doctrine set forth in _First Principles_; since, though not avowedly
directed against propositions asserted or implied in that work, Mr.
Martineau's reasoning tells against them by implication. The fulfilment
of this intention I should, however, have continued to postpone, had I
not learned that the arguments of Mr. Martineau are supposed by many to
be conclusive, and that, in the absence of replies, it will be assumed
that no replies can be made. It seems desirable, therefore, to notice
these arguments at once--especially as the essential ones may, I think,
be effectually dealt with in a comparatively small space.

       *       *       *       *       *

The first definite objection which Mr. Martineau raises is, that the
hypothesis of General Evolution is powerless to account even for the
simpler orders of facts in the absence of numerous different substances.
He argues that were matter all of one kind, no such phenomena as
chemical changes would be possible; and that, "in order to start the
world on its chemical career, you must enlarge its capital and present
it with an outfit of _heterogeneous_ constituents. Try, therefore, the
effect of such a gift; fling into the pre-existing cauldron the whole
list of recognized elementary substances, and give leave to their
affinities to work." The intended implication obviously is, that there
must exist the separately-created elements before evolution can begin.

Here, however, Mr. Martineau makes an assumption which few, if any,
chemists will commit themselves to, and which many will distinctly deny.
There are no "recognized elementary substances," if the expression means
substances known to be elementary. What chemists, for convenience, call
elementary substances, are merely substances which they have thus far
failed to decompose; but, bearing in mind past experiences, they do not
dare to say that they are absolutely undecomposable. Water was taken to
be an element for more than two thousand years, and then was proved to
be a compound; and, until Davy brought a galvanic current to bear upon
them, the alkalies and the earths were supposed to be elements. So
little true is it that "recognized elementary substances" are supposed
to be absolutely elementary, that there has been much speculation among
chemists respecting the process of compounding and recompounding by
which they have been formed out of some ultimate substance--some
chemists having supposed the atom of hydrogen to be the unit of
composition, but others having contended that the atomic weights of the
so-called elements are not thus interpretable. If I remember rightly,
Sir John Herschel was one, among others, who, some five-and-twenty years
ago, threw out suggestions respecting a system of compounding that might
explain these relations of the atomic weights.

What was at that time a suspicion has now become practically a
certainty. Spectrum-analysis yields results wholly irreconcilable with
the assumption that the conventionally-named simple substances are
really simple. Each yields a spectrum having lines varying in number
from two to eighty or more, every one of which implies the intercepting
of ethereal undulations of a certain order by something oscillating in
unison or in harmony with them. Were iron absolutely elementary, it is
not conceivable that its atom could intercept ethereal undulations of
eighty different orders. Though it does not follow that its molecule
contains as many separate atoms as there are lines in its spectrum, it
must clearly be a complex molecule. The evidence thus gained points to
the conclusion that, out of some primordial units, the so-called
elements arise by compounding and recompounding; just as by the
compounding and recompounding of so-called elements there arise oxides,
and acids, and salts.

And this hypothesis is entirely in harmony with the phenomena of
allotropy. Various substances, conventionally distinguished as simple,
have several forms under which they present quite different properties.
The semi-transparent, colourless, extremely active substance called
phosphorus may be so changed as to become opaque, dark red, and inert.
Like changes are known to occur in some gaseous, non-metallic elements,
as oxygen; and also in metallic elements, as antimony. These total
changes of properties, brought about without any changes to be called
chemical, are interpretable only as due to molecular rearrangements;
and, by showing that difference of property is producible by difference
of arrangement, they support the inference otherwise to be drawn, that
the properties of different elements result from differences of
arrangement arising by the compounding and recompounding of ultimate
homogeneous units.

Thus Mr. Martineau's objection, which at best would imply a turning of
our ignorance of the nature of elements into positive knowledge that
they are simple, is, in fact, to be met by two sets of evidences, which
imply that they are compound.

       *       *       *       *       *

Mr. Martineau next alleges that a fatal difficulty is put in the way of
the General Doctrine of Evolution by the existence of a chasm between
the living and the not-living. He says:--"But with all your enlargement
of data, turn them as you will, at the end of every passage which they
explore, the _door of life_ is closed against them still." Here again
our ignorance is employed to play the part of knowledge. The fact that
we do not know distinctly how an alleged transition has taken place, is
transformed into the assumption that no transition has taken place. We
have, in a more general shape, the argument which until lately was
thought conclusive--the argument that because the genesis of each
species of creature had not been explained, therefore each species must
have been separately created.

Merely noting this, however, I go on to remark that scientific discovery
is day by day narrowing the chasm, or, to vary Mr. Martineau's metaphor,
"opening the door." Not many years since, it was held as certain that
the chemical compounds distinguished as organic could not be formed
artificially. Now, more than a thousand organic compounds have been
formed artificially. Chemists have discovered the art of building them
up from the simpler to the more complex, and do not doubt that they will
eventually produce the most complex. Moreover, the phenomena attending
isomeric change give a clue to those movements which are the only
indications we have of life in its lowest forms. In various colloidal
substances, including the albuminoid, isomeric change is accompanied by
contraction or expansion, and consequent motion; and, in such primordial
types as the _Protogenes_ of Haeckel, which do not differ in appearance
from minute portions of albumen, the observed motions are comprehensible
as accompanying isomeric changes caused by variations in surrounding
physical actions. The probability of this interpretation will be seen on
remembering the evidence we have that, in the higher organisms, many
functions are essentially effected by isomeric changes from one to
another of the multitudinous forms which protein assumes.

Thus the reply to this objection is, first, that there is going on from
both sides a narrowing of the chasm supposed to be impassable; and,
secondly, that, even were the chasm not in course of being filled up, we
should no more be justified in therefore assuming a supernatural
commencement of life, than Kepler was justified in assuming that there
were guiding-spirits to keep the planets in their orbits, because he
could not see how else they were to be kept in their orbits.

       *       *       *       *       *

The third definite objection made by Mr. Martineau is of kindred nature.
The Hypothesis of Evolution is, he thinks, met by the insurmountable
difficulty that plant life and animal life are absolutely distinct. "You
cannot," he says, "take a single step toward the deduction of sensation
and thought: neither at the upper limit do the highest plants (the
exogens) transcend themselves and overbalance into animal existence; nor
at the lower, grope as you may among the sea-weeds and sponges, can you
persuade the sporules of the one to develop into the other."

This is an extremely unfortunate objection to raise. For, though there
are no transitions from vegetal to animal life at the places Mr.
Martineau names, where, indeed, no biologist would look for them; yet
the connexion between the two great kingdoms of living things is so
complete that separation is now regarded as impossible. For a long time
naturalists endeavored to frame definitions such as would, the one
include all plants and exclude all animals, and the other include all
animals and exclude all plants. But they have been so repeatedly foiled
in the attempt that they have given it up. There is no chemical
distinction which holds; there is no structural distinction which
holds; there is no functional distinction which holds; there is no
distinction as to mode of existence which holds. Large groups of the
simpler animals contain chlorophyll, and decompose carbonic acid under
the influence of light, as plants do. Large groups of the simpler
plants, as you may observe in the diatoms from any stagnant pool, are no
less actively locomotive than the minute creatures classed as animals
seen along with them. Nay, among these lowest types of living things, it
is common for the life to be now predominantly animal and presently to
become predominantly vegetal. The very name _zoospores_, given to germs
of _algæ_, which for a while swim about actively by means of cilia, and
presently settling down grow into plant-forms, is given because of this
conspicuous community of nature. So complete is this community of nature
that for some time past many naturalists have wished to establish for
these lowest types a sub-kingdom, intermediate between the animal and
the vegetal: the reason against this course being, however, that the
difficulty crops up afresh at any assumed places where this intermediate
sub-kingdom may be supposed to join the other two.

Thus the assumption on which Mr. Martineau proceeds is diametrically
opposed to the conviction of naturalists in general.

       *       *       *       *       *

Though I do not perceive that it is specifically stated, there appears
to be tacitly implied a fourth difficulty of allied kind--the difficulty
that there is no possibility of transition from life of the simplest
kind to mind. Mr. Martineau says, indeed, that there can be "with only
vital resources, as in the vegetable world, no beginning of mind:"
apparently leaving it to be inferred that in the animal world the
resources are such as to make the "beginning of mind" comprehensible.
If, however, instead of leaving it a latent inference, he had
distinctly asserted a chasm between mind and bodily life, for which
there is certainly quite as much reason as for asserting a chasm between
animal life and vegetal life, the difficulties in his way would have
been no less insuperable.

For those lowest forms of irritability in the animal kingdom which, I
suppose, Mr. Martineau refers to as the "beginning of mind," are not
distinguishable from the irritability which plants display: they in no
greater degree imply consciousness. If the sudden folding of a
sensitive-plant's leaf when touched, or the spreading out of the stamens
in a wild-cistus when gently brushed, is to be considered a vital action
of a purely physical kind; then so too must be considered the equally
slow contraction of a polype's tentacles. And yet, from this simple
motion of an animal of low type, we may pass by insensible stages
through ever-complicating forms of actions, with their accompanying
signs of feeling and intelligence, until we reach the highest.

Even apart from the evidence derived from the ascending grades of
animals up from _zoophytes_, as they are significantly named, it needs
only to observe the evolution of a single animal to see that there does
not exist any break or chasm between the life which shows no mind and
the life which shows mind. The yelk of an egg which the cook has just
broken, not only yields no sign of mind, but yields no sign of life. It
does not respond to a stimulus as much even as many plants do. Had the
egg, instead of being broken by the cook, been left under the hen for a
certain time, the yelk would have passed by infinitesimal gradations
through a series of forms ending in the chick; and by similarly
infinitesimal gradations would have arisen those functions which end in
the chick breaking its shell; and which, when it gets out, show
themselves in running about, distinguishing and picking up food, and
squeaking if hurt. When did the feeling begin? and how did there come
into existence that power of perception which the chick's actions show?
Should it be objected that the chick's actions are mainly automatic, I
will not dwell on the fact that, though they are largely so, the chick
manifestly has feeling and therefore consciousness; but I will accept
the objection, and propose that instead we take the human being. The
course of development before birth is just of the same general kind; and
similarly, at a certain stage, begins to be accompanied by reflex
movements. At birth there is displayed an amount of mind certainly not
greater than that of the chick: there is no power of running from
danger--no power of distinguishing and picking up food. If we say the
chick is unintelligent, we must certainly say the infant is
unintelligent. And yet from the unintelligence of the infant to the
intelligence of the adult, there is an advance by steps so small that on
no day is the amount of mind shown, appreciably different from that
shown on preceding and succeeding days.

Thus the tacit assumption that there exists a break, is not simply
gratuitous, but is negatived by the most obvious facts.

       *       *       *       *       *

Certain of the words and phrases used in explaining that particular part
of the Doctrine of Evolution which deals with the origin of species, are
commented upon by Mr. Martineau as having implications justifying his
view. Let us consider his comments.

He says that _competition_ is not an "original power, which can of
itself do anything;" further, that "it cannot act except in the presence
of some _possibility of a better or worse_;" and that this "possibility
of a better or worse" implies a "world pre-arranged for progress," "a
directing Will intent upon the good." Had Mr. Martineau looked more
closely into the matter, he would have found that, though the words and
phrases he quotes are used for convenience, the conceptions they
imply are not at all essential to the doctrine. Under its
rigorously-scientific form, the doctrine is expressible in
purely-physical terms, which neither imply competition nor imply better
and worse.[37]

Beyond this indirect mistake there is a direct mistake. Mr. Martineau
speaks of the "survivorship of the better," as though that were the
statement of the law; and then adds that the alleged result cannot be
inferred "except on the assumption that whatever is _better_ is
_stronger_ too." But the words he here uses are his own words, not the
words of those he opposes. The law is the survival of the _fittest_.
Probably, in substituting "better" for "fittest," Mr. Martineau did not
suppose that he was changing the meaning; though I dare say he perceived
that the meaning of the word "fittest" did not suit his argument so
well. Had he examined the facts, he would have found that the law is not
the survival of the "better" or the "stronger," if we give to those
words any thing like their ordinary meanings. It is the survival of
those which are constitutionally fittest to thrive under the conditions
in which they are placed; and very often that which, humanly speaking,
is inferiority, causes the survival. Superiority, whether in size,
strength, activity, or sagacity, is, other things equal, at the cost of
diminished fertility; and where the life led by a species does not
demand these higher attributes, the species profits by decrease of them,
and accompanying increase of fertility. This is the reason why there
occur so many cases of retrograde metamorphosis--this is the reason why
parasites, internal and external, are so commonly degraded forms of
higher types. Survival of the "better" does not cover these cases,
though survival of the "fittest" does; and as I am responsible for the
phrase, I suppose I am competent to say that the word "fittest" was
chosen for this reason. When it is remembered that these cases outnumber
all others--that there are more species of parasites than there are
species of all other animals put together--it will be seen that the
expression "survivorship of the better" is wholly inappropriate, and the
argument Mr. Martineau bases upon it quite untenable. Indeed, if, in
place of those adjustments of the human sense-organs, which he so
eloquently describes as implying pre-arrangement, Mr. Martineau had
described the countless elaborate appliances which enable parasites to
torture animals immeasurably superior to them, and which, from his point
of view, no less imply pre-arrangement, I think the notes of admiration
which end his descriptions would not have seemed to him so appropriate.

One more word there is from the intrinsic meaning of which Mr. Martineau
deduces what appears a powerful argument--the word _Evolution_ itself.
He says:--

     "It means, to unfold from within; and it is taken from the history
     of the seed or embryo of living natures. And what is the seed but a
     casket of pre-arranged futurities, with its whole contents
     _prospective_, settled to be what they are by reference to ends
     still in the distance?"

Now, this criticism would have been very much to the point did the word
Evolution truly express the process it names. If this process, as
scientifically defined, really involved that conception which the word
evolution was originally designed to convey, the implications would be
those Mr. Martineau alleges. But, unfortunately for him, the word,
having been in possession of the field before the process was
understood, has been adopted merely because displacing it by another
word seemed impracticable. And this adoption of it has been joined with
a caution against misunderstandings arising from its unfitness. Here is
a part of the caution:--"Evolution has other meanings, some of which are
incongruous with, and some even directly opposed to, the meaning here
given to it.... The antithetical word, Involution, would much more truly
express the nature of the process; and would, indeed, describe better
the secondary characters of the process which we shall have to deal
with presently."[38] So that the meanings which the word involves, and
which Mr. Martineau regards as fatal to the hypothesis, are already
repudiated as not belonging to the hypothesis.

       *       *       *       *       *

And now, having dealt with the essential objections raised by Mr.
Martineau to the Hypothesis of Evolution as it is presented under that
purely scientific form which generalizes the process of things, firstly
as observed and secondly as inferred from certain ultimate principles,
let me go on to examine that form of the Hypothesis which he
propounds--Evolution as determined by Mind and Will--Evolution as
pre-arranged by a Divine Actor. For Mr. Martineau apparently abandons
the primitive theory of creation by "fiat of Almighty Will", and also
the theory of creation by manufacture--by "a contriving and adapting
power," and seems to believe in evolution: requiring only that "an
originating Mind" shall be taken as its antecedent. Let us ask, first,
in what relation Mr. Martineau conceives the "originating Mind" to stand
to the evolving Universe. From some passages it is inferable that he
considers the "presence of mind" to be everywhere needful. He says:--

     "It is impossible to work the theory of Evolution upwards from the
     bottom. If all force is to be conceived as One, its type must be
     looked for in the highest and all-comprehending term; and Mind must
     be conceived as there, and as divesting itself of some speciality
     at each step of its descent to a lower stratum of law, till
     represented at the base under the guise of simple Dynamics."

This seems to be an unmistakable assertion that, wherever Evolution is
going on, Mind is then and there behind it. At the close of the
argument, however, a quite different conception is implied. Mr.
Martineau says:--

    "If the Divine Idea will not retire at the bidding of our
    speculative science, but retains its place, it is natural to ask,
    What is its relation to  the series of so-called Forces in the
    world? But the question is too large and deep to be answered here.
    Let it suffice to say, that there need not be any _overruling_ of
    these forces by the Will of God, so that the supernatural should
    disturb the natural; or any _supplementing_ of them, so that He
    should fill up their deficiencies. Rather is His thought related to
    them as, in man, the mental force is related to all below it."

It would take too much space to deal fully with the various questions
which this last passage raises. There is the question--Whence come these
"Forces," spoken of as separate from the "Will of God"--did they
pre-exist? Then what becomes of the Divine Power? Do they exist by the
Divine Will? Then what kind of nature is that by which they act apart
from the Divine Will? Again, there is the question--How do these
deputy-forces co-operate in each particular phenomenon, if the presiding
Will is not there present to control them? Either an organ which
develops into fitness for its function, develops by the co-operation of
these forces under the direction of Mind then present, or it so develops
in the absence of Mind. If it develops in the absence of Mind, the
hypothesis is given up; and if the "originating Mind" is required to be
then and there present, we must suppose a particular providence to be
present in each particular organ of each particular creature throughout
the universe. Once more there is the question--If "His thought is
related to them [these Forces] as, in Man, the mental force is related
to all below it," how can "His thought" be regarded as the cause of
Evolution? In man the mental force is related to the forces below it
neither as a creator of them nor as a regulator of them, save in a very
limited way: the greater part of the forces present in man, both
structural and functional, defy the mental force absolutely. Nay, more,
it needs but to injure a nerve to see that the power of the mental force
over the physical forces is dependent on conditions which are themselves
physical; and one who takes morphia in mistake for magnesia, discovers
that the power of the physical forces over the mental is
_un_conditioned by any thing mental.

Not dwelling on these questions, however, I will merely draw attention
to the entire incongruity of this conception with the previous
conception which I have quoted. Assuming that, when the choice is
pressed on him, Mr. Martineau will choose the first, which alone has any
thing like defensibility, let us go on to ask how far Evolution is made
more comprehensible by postulating Mind, universally immanent, as its
cause.

In metaphysical controversy, many of the propositions propounded and
accepted as quite believable, are absolutely inconceivable. There is a
perpetual confusing of actual ideas with what are nothing but
pseud-ideas. No distinction is made between propositions that contain
real thoughts, and propositions that are only the forms of thoughts. A
thinkable proposition is one of which _the two terms can be brought
together in consciousness under the relation said to exist between
them_. But very often, when the subject of a proposition has been
thought of as something known, and when the predicate has been thought
of as something known, and when the relation alleged between them has
been thought of as a known relation, it is supposed that the proposition
itself has been thought. The thinking separately of the elements of a
proposition is mistaken for the thinking of them in the combination
which the proposition affirms. And hence it continually happens that
propositions which cannot be rendered into thought at all, are supposed
to be not only thought but believed. The proposition that Evolution is
caused by Mind is one of this nature. The two terms are separately
intelligible; but they can be regarded in the relation of effect and
cause only so long as no attempt is made to put them together in this
relation.

The only thing which any one knows as Mind is the series of his own
states of consciousness; and if he thinks of any mind other than his
own, he can think of it only in terms derived from his own. If I am
asked to frame a notion of Mind divested of all those structural traits
under which alone I am conscious of mind in myself, I cannot do it. I
know nothing of thought save as carried on in ideas originally traceable
to the effects wrought by objects and forces on me. A mental act is an
unintelligible phrase if I am not to regard it as an act in which states
of consciousness are severally known as like other states in the series
that has gone by, and in which the relations between them are severally
known as like past relations in the series. If, then, I have to conceive
Evolution as caused by an "originating Mind," I must conceive this Mind
as having attributes akin to those of the only mind I know, and without
which I cannot conceive Mind at all.

I will not dwell on the many incongruities hence resulting, by asking
how the "originating Mind" is to be thought of as having states produced
by things objective to it; as discriminating among these states, and
classing them as like and unlike; and as preferring one objective result
to another. I will simply ask--What happens if we ascribe to the
"originating Mind" the character absolutely essential to the conception
of Mind, that it consists of a series of states of consciousness? Put a
series of states of consciousness as cause, and the evolving Universe as
effect, and then endeavor to see the last as flowing from the first. I
find it possible to imagine in some dim way a series of states of
consciousness serving as antecedent to any one of the movements I see
going on; for my own states of consciousness are often indirectly the
antecedents to such movements. But how if I attempt to think of such a
series as antecedent to _all_ actions throughout the Universe--to the
motions of the multitudinous stars through space, to the revolutions of
all their planets round them, to the gyrations of all these planets on
their axes, to the infinitely-multiplied physical processes going on in
each of these suns and planets? I cannot think of a single series of
states of consciousness as causing even the relatively small group of
actions going on over the Earth's surface. I cannot think of it even as
antecedent to all the various winds and the dissolving clouds they bear,
to the currents of all the rivers, and the grinding actions of all the
glaciers; still less can I think of it as antecedent to the infinity of
processes simultaneously going on in all the plants that cover the
globe, from scattered polar lichens to crowded tropical palms, and in
all the millions of quadrupeds that roam among them, and the millions of
millions of insects that buzz about them. Even to a single small set of
these multitudinous terrestrial changes, I cannot conceive as antecedent
a single series of states of consciousness--cannot, for instance, think
of it as causing the hundred thousand breakers that are at this instant
curling over on the shores of England. How, then, is it possible for me
to conceive an "originating Mind," which I must represent to myself as a
_single_ series of states of consciousness, working the
infinitely-multiplied sets of changes _simultaneously_ going on in
worlds too numerous to count, dispersed throughout a space that baffles
imagination?

If, to account for this infinitude of physical changes everywhere going
on, "Mind must be conceived as there" "under the guise of simple
Dynamics," then the reply is that, to be so conceived, Mind must be
divested of all attributes by which it is distinguished; and that, when
thus divested of its distinguishing attributes, the conception
disappears--the word Mind stands for a blank. If Mr. Martineau takes
refuge in the entirely different and, as it seems to me, incongruous
hypothesis of something like a plurality of minds--if he accepts, as he
seems to do, the doctrine that you cannot explain Evolution "unless
among your primordial elements you scatter already the _germs_ of Mind
as well as the inferior elements"--if the insuperable difficulties I
have just pointed out are to be met by assuming a local series of states
of consciousness for each phenomenon, then we are obviously carried
back to something like the alleged fetichistic notion, with the
difference only, that the assumed spiritual agencies are indefinitely
multiplied.

Clearly, therefore, the proposition that an "originating Mind" is the
cause of Evolution, is a proposition that can be entertained so long
only as no attempt is made to unite in thought its two terms in the
alleged relation. That it should be accepted as a matter of _faith_, may
be a defensible position, provided good cause is shown why it should be
so accepted; but that it should be accepted as a matter of
_understanding_--as a statement making the order of the universe
comprehensible--is a quite indefensible position.

       *       *       *       *       *

Here let me guard myself against a misinterpretation very likely to be
put upon the foregoing arguments; especially by those who have read the
Essay to which they reply. The statements of that Essay carry the
implication that all who adhere to the hypothesis it combats, imagine
they have solved the mystery of things when they have shown the
processes of Evolution to be naturally caused. Mr. Martineau tacitly
represents them as believing that, when every thing has been interpreted
in terms of Matter and Motion, nothing remains to be explained. This,
however, is by no means the fact. The Doctrine of Evolution, under its
purely scientific form, does not involve Materialism, though its
opponents persistently represent it as doing so. Indeed, among adherents
of it who are friends of mine, there are those who speak of the
Materialism of Buechner and his school, with a contempt certainly not
less than that felt by Mr. Martineau. To show how anti-materialistic my
own view is, I may, perhaps, without impropriety, quote some out of many
passages which I have written on the question elsewhere:

     "Hence though of the two it seems easier to translate so-called
     Matter into so-called Spirit, than to translate so-called Spirit
     into so-called Matter (which latter is, indeed, wholly
     impossible); yet no translation can carry us beyond our
     symbols."[39]

And again:

     "See then our predicament. We can think of Matter only in terms of
     Mind. We can think of Mind only in terms of Matter. When we have
     pushed our explorations of the first to the uttermost limit, we are
     referred to the second for a final answer; and, when we have got
     the final answer of the second, we are referred back to the first
     for an interpretation of it. We find the value of _x_ in terms of
     _y_; then we find the value of _y_ in terms of _x_; and so on we
     may continue forever without coming nearer to a solution. The
     antithesis of subject and object, never to be transcended while
     consciousness lasts, renders impossible all knowledge of that
     Ultimate Reality in which subject and object are united."[40]

It is thus, I think, manifest that the difference between Mr.
Martineau's view and the view he opposes is by no means so wide as he
makes it appear; and further, it seems to me that such difference as
exists is rather the reverse of that indicated by his exposition.
Briefly expressed, the difference is that, where he thinks there is no
mystery, the doctrine he combats recognizes a mystery. Speaking for
myself only, I may say that, agreeing entirely with Mr. Martineau in
repudiating the materialistic interpretation as utterly futile, I differ
from him simply in this, that while he says he has found another
interpretation, I confess that I cannot find any interpretation; while
he holds that he can understand the Power which is manifested in things,
I feel obliged to admit, after many failures, that I cannot understand
it. So that, in presence of the transcendent problem which the universe
presents, Mr. Martineau regards the human intellect as capable, and I as
incapable. This contrast does not appear to me of the kind which his
Essay tacitly asserts. If there is such a thing as the "pride of
Science," it is obviously exceeded by the pride of Theology. I fail to
perceive humility in the belief that the human mind is able to
comprehend that which is behind appearances; and I do not see how piety
is especially exemplified in the assertion that the Universe contains
no mode of existence higher in Nature than that which is present to us
in consciousness. On the contrary, I think it quite a defensible
proposition that humility is better shown by a confession of
incompetence to grasp in thought the Cause of all things; and that the
religious sentiment may find its highest sphere in the belief that the
Ultimate Power is no more representable in terms of human consciousness
than human consciousness is representable in terms of a plant's
functions.

FOOTNOTES:

[Footnote 37: _Principles of Biology_, §§ 159-168.]

[Footnote 38: _First Principles_, second edition, § 97.]

[Footnote 39: _Principles of Psychology_, second edition, vol. i., §
63.]

[Footnote 40: Ibid., § 272.]




THE FACTORS OF ORGANIC EVOLUTION.

    [_First published in_ The Nineteenth Century_, for April and May_,
    1886.]


I.

Within the recollection of men now in middle life, opinion concerning
the derivation of animals and plants was in a chaotic state. Among the
unthinking there was tacit belief in creation by miracle, which formed
an essential part of the creed of Christendom; and among the thinking
there were two parties, each of which held an indefensible hypothesis.
Immensely the larger of these parties, including nearly all whose
scientific culture gave weight to their judgments, though not accepting
literally the theologically-orthodox doctrine, made a compromise between
that doctrine and the doctrines which geologists had established; while
opposed to them were some, mostly having no authority in science, who
held a doctrine which was heterodox both theologically and
scientifically. Professor Huxley, in his lecture on "The Coming of Age
of the Origin of Species," remarks concerning the first of these parties
as follows:--

     "One-and-twenty years ago, in spite of the work commenced by Hutton
     and continued with rare skill and patience by Lyell, the dominant
     view of the past history of the earth was catastrophic. Great and
     sudden physical revolutions, wholesale creations and extinctions of
     living beings, were the ordinary machinery of the geological epic
     brought into fashion by the misapplied genius of Cuvier. It was
     gravely maintained and taught that the end of every geological
     epoch was signalised by a cataclysm, by which every living being on
     the globe was swept away, to be replaced by a brand-new creation
     when the world returned to quiescence. A scheme of nature which
     appeared to be modelled on the likeness of a succession of rubbers
     of whist, at the end of each of which the players upset the table
     and called for a new pack, did not seem to shock anybody.

     I may be wrong, but I doubt if, at the present time, there is a
     single responsible representative of these opinions left. The
     progress of scientific geology has elevated the fundament principle
     of uniformitarianism, that the explanation of the past is to be
     sought in the study of the present, into the position of an axiom;
     and the wild speculations of the catastrophists, to which we all
     listened with respect a quarter of a century ago, would hardly find
     a single patient hearer at the present day."

Of the party above referred to as not satisfied with this conception
described by Professor Huxley, there were two classes. The great
majority were admirers of the _Vestiges of the Natural History of
Creation_--a work which, while it sought to show that organic evolution
has taken place, contended that the cause of organic evolution, is "an
impulse" supernaturally "imparted to the forms of life, advancing them,
... through grades of organization." Being nearly all very inadequately
acquainted with the facts, those who accepted the view set forth in the
_Vestiges_ were ridiculed by the well-instructed for being satisfied
with evidence, much of which was either invalid or easily cancelled by
counter-evidence, and at the same time they exposed themselves to the
ridicule of the more philosophical for being content with a supposed
explanation which was in reality no explanation: the alleged "impulse"
to advance giving us no more help in understanding the facts than does
Nature's alleged "abhorrence of a vacuum" help us to understand the
ascent of water in a pump. The remnant, forming the second of these
classes, was very small. While rejecting this mere verbal solution,
which both Dr. Erasmus Darwin and Lamarck had shadowed forth in other
language, there were some few who, rejecting also the hypothesis
indicated by both Dr. Darwin and Lamarck, that the promptings of desires
or wants produced growths of the parts subserving them, accepted the
single _vera causa_ assigned by these writers--the modification of
structures resulting from modification of functions. They recognized
as the sole process in organic development, the adaptation of parts and
powers consequent on the effects of use and disuse--that continual
moulding and re-moulding of organisms to suit their circumstances, which
is brought about by direct converse with such circumstances.

But while this cause accepted by these few is a true cause, since
unquestionably during the life of the individual organism changes of
function produce changes of structure; and while it is a tenable
hypothesis that changes of structure so produced are inheritable; yet it
was manifest to those not prepossessed, that this cause cannot with
reason be assigned for the greater part of the facts. Though in plants
there are some characters which may not irrationally be ascribed to the
direct effects of modified functions consequent on modified
circumstances, yet the majority of the traits presented by plants are
not to be thus explained. It is impossible that the thorns by which a
briar is in large measure defended against browsing animals, can have
been developed and moulded by the continuous exercise of their
protective actions; for in the first place, the great majority of the
thorns are never touched at all, and, in the second place, we have no
ground whatever for supposing that those which are touched are thereby
made to grow, and to take those shapes which render them efficient.
Plants which are rendered uneatable by the thick woolly coatings of
their leaves, cannot have had these coatings produced by any process of
reaction against the action of enemies; for there is no imaginable
reason why, if one part of a plant is eaten, the rest should thereafter
begin to develop the hairs on its surface. By what direct effect of
function on structure, can the shell of a nut have been evolved? Or how
can those seeds which contain essential oils, rendering them unpalatable
to birds, have been made to secrete such essential oils by these actions
of birds which they restrain? Or how can the delicate plumes borne by
some seeds, and giving the wind power to waft them to new stations, be
due to any immediate influences of surrounding conditions? Clearly in
these and in countless other cases, change of structure cannot have been
directly caused by change of function. So is it with animals to a large
extent, if not to the same extent. Though we have proof that by rough
usage the dermal layer may be so excited as to produce a greatly
thickened epidermal layer, sometimes quite horny; and though it is a
feasible hypothesis that an effect of this kind persistently produced
may be inherited; yet no such cause can explain the carapace of the
turtle, the armour of the armadillo, or the imbricated covering of the
manis. The skins of these animals are no more exposed to habitual hard
usage than are those of animals covered by hair. The strange
excrescences which distinguish the heads of the hornbills, cannot
possibly have arisen from any reaction against the action of surrounding
forces; for even were they clearly protective, there is no reason to
suppose that the heads of these birds need protection more than the
heads of other birds. If, led by the evidence that in animals the amount
of covering is in some cases affected by the degree of exposure, it were
admitted as imaginable that the development of feathers from preceding
dermal growths had resulted from that extra nutrition caused by extra
superficial circulation, we should still be without explanation of the
structure of a feather. Nor should we have any clue to the specialities
of feathers--the crests of various birds, the tails sometimes so
enormous, the curiously placed plumes of the bird of paradise, &c., &c.
Still more obviously impossible is it to explain as due to use or disuse
the colours of animals. No direct adaptation to function could have
produced the blue protuberances on a mandril's face, or the striped hide
of a tiger, or the gorgeous plumage of a kingfisher, or the eyes in a
peacock's tail, or the multitudinous patterns of insects' wings. One
single case, that of a deer's horns, might alone have sufficed to show
how insufficient was the assigned cause. During their growth, a deer's
horns are not used at all; and when, having been cleared of the dead
skin and dried-up blood-vessels covering them, they are ready for use,
they are nerveless and non-vascular, and hence are incapable of
undergoing any changes of structure consequent on changes of function.

Of these few then, who rejected the belief described by Professor
Huxley, and who, espousing the belief in a continuous evolution, had to
account for this evolution, it must be said that though the cause
assigned was a true cause, yet, even admitting that it operated through
successive generations, it left unexplained the greater part of the
facts. Having been myself one of these few, I look back with surprise at
the way in which the facts which were congruous with the espoused view
monopolized consciousness and kept out the facts which were incongruous
with it--conspicuous though many of them were. The misjudgment was not
unnatural. Finding it impossible to accept any doctrine which implied a
breach in the uniform course of natural causation, and, by implication,
accepting as unquestionable the origin and development of all organic
forms by accumulated modifications naturally caused, that which appeared
to explain certain classes of these modifications, was supposed to be
capable of explaining the rest: the tendency being to assume that these
would eventually be similarly accounted for, though it was not clear
how.

Returning from this parenthetic remark, we are concerned here chiefly to
remember that, as said at the outset, there existed thirty years ago, no
tenable theory about the genesis of living things. Of the two
alternative beliefs, neither would bear critical examination.

       *       *       *       *       *

Out of this dead lock we were released--in large measure, though not I
believe entirely--by the _Origin of Species_. That work brought into
view a further factor; or rather, such factor, recognized as in
operation by here and there an observer (as pointed out by Mr. Darwin in
his introduction to the second edition), was by him for the first time
seen to have played so immense a part in the genesis of plants and
animals.

Though laying myself open to the charge of telling a thrice-told tale, I
feel obliged here to indicate briefly the several great classes of facts
which Mr. Darwin's hypothesis explains; because otherwise that which
follows would scarcely be understood. And I feel the less hesitation in
doing this because the hypothesis which it replaced, not very widely
known at any time, has of late so completely dropped into the
background, that the majority of readers are scarcely aware of its
existence, and do not therefore understand the relation between Mr.
Darwin's successful interpretation and the preceding unsuccessful
attempt at interpretation. Of these classes of facts, four chief ones
may be here distinguished.

In the first place, such adjustments as those exemplified above are made
comprehensible. Though it is inconceivable that a structure like that of
the pitcher-plant could have been produced by accumulated effects of
function on structure; yet it is conceivable that successive selections
of favourable variations might have produced it; and the like holds of
the no less remarkable appliance of the Venus's Fly-trap, or the still
more astonishing one of that water-plant by which infant-fish are
captured. Though it is impossible to imagine how, by direct influence of
increased use, such dermal appendages as a porcupine's quills could have
been developed; yet, profiting as the members of a species otherwise
defenceless might do by the stiffness of their hairs, rendering them
unpleasant morsels to eat, it is a feasible supposition that from
successive survivals of individuals thus defended in the greatest
degrees, and the consequent growth in successive generations of hairs
into bristles, bristles into spines, spines into quills (for all these
are homologous), this change could have arisen. In like manner, the odd
inflatable bag of the bladder-nosed seal, the curious fishing-rod with
its worm-like appendage carried on the head of the _lophius_ or angler,
the spurs on the wings of certain birds, the weapons of the sword-fish
and saw-fish, the wattles of fowls, and numberless such peculiar
structures, though by no possibility explicable as due to effects of use
or disuse, are explicable as resulting from natural selection operating
in one or other way.

In the second place, while showing us how there have arisen countless
modifications in the forms, structures, and colours of each part, Mr.
Darwin has shown us how, by the establishment of favourable variations,
there may arise new parts. Though the first step in the production of
horns on the heads of various herbivorous animals, may have been the
growth of callosities consequent on the habit of butting--such
callosities thus functionally initiated being afterwards developed in
the most advantageous ways by selection; yet no explanation can be thus
given of the sudden appearance of a duplicate set of horns, as
occasionally happens in sheep: an addition which, where it proved
beneficial, might readily be made a permanent trait by natural
selection. Again, the modifications which follow use and disuse can by
no possibility account for changes in the numbers of vertebræ; but after
recognizing spontaneous, or rather fortuitous, variation as a factor, we
can see that where an additional vertebra hence resulting (as in some
pigeons) proves beneficial, survival of the fittest may make it a
constant character; and there may, by further like additions, be
produced extremely long strings of vertebræ, such as snakes show us.
Similarly with the mammary glands. It is not an unreasonable supposition
that by the effects of greater or less function, inherited through
successive generations, these may be enlarged or diminished in size; but
it is out of the question to allege such a cause for changes in their
numbers. There is no imaginable explanation of these save the
establishment by inheritance of spontaneous variations, such as are
known to occur in the human race.

So too, in the third place, with certain alterations in the connexions
of parts. According to the greater or smaller demands made on this or
that limb, the muscles moving it may be augmented or diminished in bulk;
and, if there is inheritance of changes so wrought, the limb may, in
course of generations, be rendered larger or smaller. But changes in the
arrangements or attachments of muscles cannot be thus accounted for. It
is found, especially at the extremities, that the relations of tendons
to bones and to one another are not always the same. Variations in their
modes of connexion may occasionally prove advantageous, and may thus
become established. Here again, then, we have a class of structural
changes to which Mr. Darwin's hypothesis gives us the key, and to which
there is no other key.

Once more there are the phenomena of mimicry. Perhaps in a more striking
way than any others, these show how traits which seem inexplicable are
explicable as due to the more frequent survival of individuals that have
varied in favourable ways. We are enabled to understand such marvellous
simulations as those of the leaf-insect, those of beetles which
"resemble glittering dew-drops upon the leaves;" those of caterpillars
which, when asleep, stretch themselves out so as to look like twigs. And
we are shown how there have arisen still more astonishing
imitations--those of one insect by another. As Mr. Bates has proved,
there are cases in which a species of butterfly, rendered so unpalatable
to insectivorous birds by its disagreeable taste that they will not
catch it, is simulated in its colours and markings by a species which is
structurally quite different--so simulated that even a practised
entomologist is liable to be deceived: the explanation being that an
original slight resemblance, leading to occasional mistakes on the part
of birds, was increased generation after generation by the more frequent
escape of the most-like individuals, until the likeness became thus
great.

But now, recognizing in full this process brought into clear view by Mr.
Darwin, and traced out by him with so much care and skill, can we
conclude that, taken alone, it accounts for organic evolution? Has the
natural selection of favourable variations been the sole factor? On
critically examining the evidence, we shall find reason to think that it
by no means explains all that has to be explained. Omitting for the
present any consideration of a factor which may be distinguished as
primordial, it may be contended that the above-named factor alleged by
Dr. Erasmus Darwin and by Lamarck, must be recognized as a co-operator.
Utterly inadequate to explain the major part of the facts as is the
hypothesis of the inheritance of functionally-produced modifications,
yet there is a minor part of the facts, very extensive though less,
which must be ascribed to this cause.

       *       *       *       *       *

When discussing the question more than twenty years ago (_Principles of
Biology_, § 166), I instanced the decreased size of the jaws in the
civilized races of mankind, as a change not accounted for by the natural
selection of favourable variations; since no one of the decrements by
which, in thousands of years, this reduction has been effected, could
have given to an individual in which it occurred, such advantage as
would cause his survival, either through diminished cost of local
nutrition or diminished weight to be carried. I did not then exclude, as
I might have done, two other imaginable causes. It may be said that
there is some organic correlation between increased size of brain and
decreased size of jaw: Camper's doctrine of the facial angle being
referred to in proof. But this argument may be met by pointing to the
many examples of small-jawed people who are also small-brained, and by
citing not infrequent cases of individuals remarkable for their mental
powers, and at the same time distinguished by jaws not less than the
average but greater. Again, if sexual selection be named as a possible
cause, there is the reply that, even supposing such slight diminution of
jaw as took place in a single generation to have been an attraction, yet
the other incentives to choice on the part of men have been too many and
great to allow this one to weigh in an adequate degree; while, during
the greater portion of the period, choice on the part of women has
scarcely operated: in earlier times they were stolen or bought, and in
later times mostly coerced by parents. Thus, reconsideration of the
facts does not show me the invalidity of the conclusion drawn, that this
decrease in size of jaw can have had no other cause than continued
inheritance of those diminutions consequent on diminutions of function,
implied by the use of selected and well-prepared food. Here, however, my
chief purpose is to add an instance showing, even more clearly, the
connexion between change of function and change of structure. This
instance, allied in nature to the other, is presented by those
varieties, or rather sub-varieties, of dogs, which, having been
household pets, and habitually fed on soft food, have not been called on
to use their jaws in tearing and crunching, and have been but rarely
allowed to use them in catching prey and in fighting. No inference can
be drawn from the sizes of the jaws themselves, which, in these dogs,
have probably been shortened mainly by selection. To get direct proof of
the decrease of the muscles concerned in closing the jaws or biting,
would require a series of observations very difficult to make. But it is
not difficult to get indirect proof of this decrease by looking at the
bony structures with which these muscles are connected. Examination of
the skulls of sundry indoor dogs contained in the Museum of the College
of Surgeons, proves the relative smallness of such parts. The only
pug-dog's skull is that of an individual not perfectly adult; and though
its traits are quite to the point they cannot with safety be taken as
evidence. The skull of a toy-terrier has much restricted areas of
insertion for the temporal muscles; has weak zygomatic arches; and has
extremely small attachments for the masseter muscles. Still more
significant is the evidence furnished by the skull of a King Charles's
spaniel, which, if we allow three years to a generation, and bear in
mind that the variety must have existed before Charles the Second's
reign, we may assume belongs to something approaching to the hundredth
generation of these household pets. The relative breadth between the
outer surfaces of the zygomatic arches is conspicuously small; the
narrowness of the temporal fossæ is also striking; the zygomata are very
slender; the temporal muscles have left no marks whatever, either by
limiting lines or by the character of the surfaces covered; and the
places of attachment for the masseter muscles are very feebly developed.
At the Museum of Natural History, among skulls of dogs there is one
which, though unnamed, is shown by its small size and by its teeth, to
have belonged to one variety or other of lap-dogs, and which has the
same traits in an equal degree with the skull just described. Here,
then, we have two if not three kinds of dogs which, similarly leading
protected and pampered lives, show that in the course of generations the
parts concerned in clenching the jaws have dwindled. To what cause must
this decrease be ascribed? Certainly not to artificial selection; for
most of the modifications named make no appreciable external signs: the
width across the zygomata could alone be perceived. Neither can natural
selection have had anything to do with it; for even were there any
struggle for existence among such dogs, it cannot be contended that any
advantage in the struggle could be gained by an individual in which a
decrease took place. Economy of nutrition, too, is excluded. Abundantly
fed as such dogs are, the constitutional tendency is to find places
where excess of absorbed nutriment may be conveniently deposited, rather
than to find places where some cutting down of the supplies is
practicable. Nor again can there be alleged a possible correlation
between these diminutions and that shortening of the jaws which has
probably resulted from selection; for in the bull-dog, which has also
relatively short jaws, these structures concerned in closing them are
unusually large. Thus there remains as the only conceivable cause, the
diminution of size which results from diminished use. The dwindling of a
little-exercised part has, by inheritance, been made more and more
marked in successive generations.

       *       *       *       *       *

Difficulties of another class may next be exemplified--those which
present themselves when we ask how there can be effected by the
selection of favourable variations, such changes of structure as adapt
an organism to some useful action in which many different parts
co-operate. None can fail to see how a simple part may, in course of
generations, be greatly enlarged, if each enlargement furthers, in some
decided way, maintenance of the species. It is easy to understand, too,
how a complex part, as an entire limb, may be increased as a whole by
the simultaneous due increase of its co-operative parts; since if, while
it is growing, the channels of supply bring to the limb an unusual
quantity of blood, there will naturally result a proportionately greater
size of all its components--bones, muscles, arteries, veins, &c. But
though in cases like this, the co-operative parts forming some large
complex part may be expected to vary together, nothing implies that they
necessarily do so; and we have proof that in various cases, even when
closely united, they do not do so. An example is furnished by those
blind crabs named in the _Origin of Species_ which inhabit certain dark
caves of Kentucky, and which, though they have lost their eyes, have
not lost the foot-stalks which carried their eyes. In describing the
varieties which have been produced by pigeon-fanciers, Mr. Darwin notes
the fact that along with changes in length of beak produced by
selection, there have not gone proportionate changes in length of
tongue. Take again the case of teeth and jaws. In mankind these have not
varied together. During civilization the jaws have decreased, but the
teeth have not decreased in proportion; and hence that prevalent
crowding of them, often remedied in childhood by extraction of some, and
in other cases causing that imperfect development which is followed by
early decay. But the absence of proportionate variation in co-operative
parts that are close together, and are even bound up in the same mass,
is best seen in those varieties of dogs named above as illustrating the
inherited effects of disuse. We see in them, as we see in the human
race, that diminution in the jaws has not been accompanied by
corresponding diminution in the teeth. In the catalogue of the College
of Surgeons Museum, there is appended to the entry which identifies a
Blenheim Spaniel's skull, the words--"the teeth are closely crowded
together," and to the entry concerning the skull of a King Charles's
Spaniel the words--"the teeth are closely packed, p. 3, is placed quite
transversely to the axis of the skull." It is further noteworthy that in
a case where there is no diminished use of the jaws, but where they have
been shortened by selection, a like want of concomitant variation is
manifested: the case being that of the bull-dog, in the upper jaw of
which also, "the premolars ... are excessively crowded, and placed
obliquely or even transversely to the long axis of the skull."[41]

If, then, in cases where we can test it, we find no concomitant
variation in co-operative parts that are near together--if we do not
find it in parts which, though belonging to different tissues, are so
closely united as teeth and jaws--if we do not find it even when the
co-operative parts are not only closely united, but are formed out of
the same tissue, like the crab's eye and its peduncle; what shall we say
of co-operative parts which, besides being composed of different
tissues, are remote from one another? Not only are we forbidden to
assume that they vary together, but we are warranted in asserting that
they can have no tendency to vary together. And what are the
implications in cases where increase of a structure can be of no service
unless there is concomitant increase in many distant structures, which
have to join it in performing the action for which it is useful?

As far back as 1864 (_Principles of Biology_, § 166) I named in
illustration an animal carrying heavy horns--the extinct Irish elk; and
indicated the many changes in bones, muscles, blood-vessels, nerves,
composing the fore-part of the body, which would be required to make an
increment of size in such horns advantageous. Here let me take another
instance--that of the giraffe: an instance which I take partly because,
in the sixth edition of the _Origin of Species_, issued in 1872, Mr.
Darwin has referred to this animal when effectually disposing of certain
arguments urged against his hypothesis. He there says:--

     "In order that an animal should acquire some structure specially
     and largely developed, it is almost indispensable that several
     other parts should be modified and co-adapted. Although every part
     of the body varies slightly, it does not follow that the necessary
     parts should always vary in the right direction and to the right
     degree" (p. 179).

And in the summary of the chapter, he remarks concerning the adjustments
in the same quadruped, that "the prolonged use of all the parts together
with inheritance will have aided in an important manner in their
co-ordination" (p. 199): a remark probably having reference chiefly to
the increased massiveness of the lower part of the neck; the increased
size and strength of the thorax required to bear the additional burden;
and the increased strength of the fore-legs required to carry the
greater weight of both. But now I think that further consideration
suggests the belief that the entailed modifications are much more
numerous and remote than at first appears; and that the greater part of
these are such as cannot be ascribed in any degree to the selection of
favourable variations, but must be ascribed exclusively to the inherited
effects of changed functions. Whoever has seen a giraffe gallop will
long remember the sight as a ludicrous one. The reason for the
strangeness of the motions is obvious. Though the fore limbs and the
hind limbs differ so much in length, yet in galloping they have to keep
pace--must take equal strides. The result is that at each stride, the
angle which the hind limbs describe round their centre of motion is much
larger than the angle described by the fore limbs. And beyond this, as
an aid in equalizing the strides, the hind part of the back is at each
stride bent very much downwards and forwards. Hence the hind-quarters
appear to be doing nearly all the work. Now a moment's observation shows
that the bones and muscles composing the hind-quarters of the giraffe,
perform actions differing in one or other way and degree, from the
actions performed by the homologous bones and muscles in a mammal of
ordinary proportions, and from those in the ancestral mammal which gave
origin to the giraffe. Each further stage of that growth which produced
the large fore-quarters and neck, entailed some adapted change in sundry
of the numerous parts composing the hind-quarters; since any failure in
the adjustment of their respective strengths would entail some defect in
speed and consequent loss of life when chased. It needs but to remember
how, when continuing to walk with a blistered foot, the taking of steps
in such a modified way as to diminish pressure on the sore point, soon
produces aching of muscles which are called into unusual action, to see
that over-straining of any one of the muscles of the giraffe's
hind-quarters might quickly incapacitate the animal when putting out all
its powers to escape; and to be a few yards behind others would cause
death. Hence if we are debarred from assuming that co-operative parts
vary together even when adjacent and closely united--if we are still
more debarred from assuming that with increased length of fore-legs or
of neck, there will go an appropriate change in any one muscle or bone
in the hind-quarters; how entirely out of the question it is to assume
that there will simultaneously take place the appropriate changes in
_all_ those many components of the hind-quarters which severally require
re-adjustment. It is useless to reply that an increment of length in the
fore-legs or neck might be retained and transmitted to posterity,
waiting an appropriate variation in a particular bone or muscle in the
hind-quarters, which, being made, would allow of a further increment.
For besides the fact that until this secondary variation occurred the
primary variation would be a disadvantage often fatal; and besides the
fact that before such an appropriate secondary variation might be
expected in the course of generations to occur, the primary variation
would have died out; there is the fact that the appropriate variation of
one bone or muscle in the hind-quarters would be useless without
appropriate variations of all the rest--some in this way and some in
that--a number of appropriate variations which it is impossible to
suppose.

Nor is this all. Far more numerous appropriate variations would be
indirectly necessitated. The immense change in the ratio of
fore-quarters to hind-quarters would make requisite a corresponding
change of ratio in the appliances carrying on the nutrition of the two.
The entire vascular system, arterial and veinous, would have to undergo
successive unbuildings and rebuildings to make its channels everywhere
adequate to the local requirements; since any want of adjustment in the
blood-supply in this or that set of muscles, would entail incapacity,
failure of speed, and loss of life. Moreover the nerves supplying the
various sets of muscles would have to be proportionately changed; as
well as the central nervous tracts from which they issued. Can we
suppose that all these appropriate changes, too, would be step by step
simultaneously made by fortunate spontaneous variations, occurring along
with all the other fortunate spontaneous variations? Considering how
immense must be the number of these required changes, added to the
changes above enumerated, the chances against any adequate
re-adjustments fortuitously arising must be infinity to one.

If the effects of use and disuse of parts are inheritable, then any
change in the fore parts of the giraffe which affects the action of the
hind limbs and back, will simultaneously cause, by the greater or less
exercise of it, a re-moulding of each component in the hind limbs and
back in a way adapted to the new demands; and generation after
generation the entire structure of the hind-quarters will be
progressively fitted to the changed structure of the fore-quarters: all
the appliances for nutrition and innervation being at the same time
progressively fitted to both. But in the absence of this inheritance of
functionally-produced modifications, there is no seeing how the required
re-adjustments can be made.

       *       *       *       *       *

Yet a third class of difficulties stands in the way of the belief that
the natural selection of useful variations is the sole factor of organic
evolution. This class of difficulties, already pointed out in § 166 of
the _Principles of Biology_, I cannot more clearly set forth than in the
words there used. Hence I may perhaps be excused for here quoting them.

     "Where the life is comparatively simple, or where surrounding
     circumstances render some one function supremely important, the
     survival of the fittest may readily bring about the appropriate
     structural change, without any aid from the transmission of
     functionally-acquired modifications. But in proportion as the life
     grows complex--in proportion as a healthy existence cannot be
     secured by a large endowment of some one power, but demands many
     powers; in the same proportion do there arise obstacles to the
     increase of any particular power, by 'the preservation of favoured
     races in the struggle for life.' As fast as the faculties are
     multiplied, so fast does it become possible for the several members
     of a species to have various kinds of superiorities over one
     another. While one saves its life by higher speed, another does the
     like by clearer vision, another by keener scent, another by quicker
     hearing, another by greater strength, another by unusual power of
     enduring cold or hunger, another by special sagacity, another by
     special timidity, another by special courage; and others by other
     bodily and mental attributes. Now it is unquestionably true that,
     other things equal, each of these attributes, giving its possessor
     an extra chance of life, is likely to be transmitted to posterity.
     But there seems no reason to suppose that it will be increased in
     subsequent generations by natural selection. That it may be thus
     increased, the individuals not possessing more than average
     endowments of it, must be more frequently killed off than
     individuals highly endowed with it; and this can happen only when
     the attribute is one of greater importance, for the time being,
     than most of the other attributes. If those members of the species
     which have but ordinary shares of it, nevertheless survive by
     virtue of other superiorities which they severally possess; then it
     is not easy to see how this particular attribute can be developed
     by natural selection in subsequent generations. The probability
     seems rather to be, that by gamogenesis, this extra endowment will,
     on the average, be diminished in posterity--just serving in the
     long run to compensate the deficient endowments of other
     individuals, whose special powers lie in other directions; and so
     to keep up the normal structure of the species. The working out of
     the process is here somewhat difficult to follow; but it appears to
     me that as fast as the number of bodily and mental faculties
     increases, and as fast as the maintenance of life comes to depend
     less on the amount of any one, and more on the combined action of
     all; so fast does the production of specialities of character by
     natural selection alone, become difficult. Particularly does this
     seem to be so with a species so multitudinous in its powers as
     mankind; and above all does it seem to be so with such of the human
     powers as have but minor shares in aiding the struggle for
     life--the æsthetic faculties, for example."

Dwelling for a moment on this last illustration of the class of
difficulties described, let us ask how we are to interpret the
development of the musical faculty. I will not enlarge on the family
antecedents of the great composers. I will merely suggest the inquiry
whether the greater powers possessed by Beethoven and Mozart, by Weber
and Rossini, than by their fathers, were not due in larger measure to
the inherited effects of daily exercise of the musical faculty by their
fathers, than to inheritance, with increase, of spontaneous variations;
and whether the diffused musical powers of the Bach clan, culminating in
those of Johann Sebastian, did not result in part from constant
practice; but I will raise the more general question--How came there
that endowment of musical faculty which characterizes modern Europeans
at large, as compared with their remote ancestors. The monotonous chants
of low savages cannot be said to show any melodic inspiration; and it is
not evident that an individual savage who had a little more musical
perception than the rest, would derive any such advantage in the
maintenance of life as would secure the spread of his superiority by
inheritance of the variation. And then what are we to say of harmony? We
cannot suppose that the appreciation of this, which is relatively
modern, can have arisen by descent from the men in whom successive
variations increased the appreciation of it--the composers and musical
performers; for on the whole, these have been men whose worldly
prosperity was not such as enabled them to rear many children inheriting
their special traits. Even if we count the illegitimate ones, the
survivors of these added to the survivors of the legitimate ones, can
hardly be held to have yielded more than average numbers of descendants;
and those who inherited their special traits have not often been thereby
so aided in the struggle for existence as to further the spread of such
traits. Rather the tendency seems to have been the reverse.

Since the above passage was written, I have found in the second volume
of _Animals and Plants under Domestication_, a remark made by Mr.
Darwin, practically implying that among creatures which depend for their
lives on the efficiency of numerous powers, the increase of any one by
the natural selection of a variation is necessarily difficult. Here it
is.

     "Finally, as indefinite and almost illimitable variability is the
     usual result of domestication and cultivation, with the same part
     or organ varying in different individuals in different or even in
     directly opposite ways; and as the same variation, if strongly
     pronounced, usually recurs only after long intervals of time, any
     particular variation would generally be lost by crossing,
     reversion, and the accidental destruction of the varying
     individuals, unless carefully preserved by man."--Vol. ii, 292.

Remembering that mankind, subject as they are to this domestication and
cultivation, are not, like domesticated animals, under an agency which
picks out and preserves particular variations; it results that there
must usually be among them, under the influence of natural selection
alone, a continual disappearance of any useful variations of particular
faculties which may arise. Only in cases of variations which are
specially preservative, as for example, great cunning during a
relatively barbarous state, can we expect increase from natural
selection alone. We cannot suppose that minor traits, exemplified among
others by the æsthetic perceptions, can have been evolved by natural
selection. But if there is inheritance of functionally-produced
modifications of structure, evolution of such minor traits is no longer
inexplicable.

       *       *       *       *       *

Two remarks made by Mr. Darwin have implications from which the same
general conclusion must, I think, be drawn. Speaking of the variability
of animals and plants under domestication, he says:--

     "Changes of any kind in the conditions of life, even extremely
     slight changes, often suffice to cause variability.... Animals and
     plants continue to be variable for an immense period after their
     first domestication; ... In the course of time they can be
     habituated to certain changes, so as to become less variable; ...
     There is good evidence that the power of changed conditions
     accumulates; so that two, three, or more generations must be
     exposed to new conditions before any effect is visible.... Some
     variations are induced by the direct action of the surrounding
     conditions on the whole organization, or on certain parts alone,
     and other variations are induced indirectly through the
     reproductive system being affected in the same manner as is so
     common with organic beings when removed from their natural
     conditions."--(_Animals and Plants under Domestication_, vol. ii,
     270.)

There are to be recognized two modes of this effect produced by changed
conditions on the reproductive system, and consequently on offspring.
Simple arrest of development is one. But beyond the variations of
offspring arising from imperfectly developed reproductive systems in
parents--variations which must be ordinarily in the nature of
imperfections--there are others due to a changed balance of functions
caused by changed conditions. The fact noted by Mr. Darwin in the above
passage, "that the power of changed conditions accumulates; so that two,
three, or more generations must be exposed to new conditions before any
effect is visible," implies that during these generations there is going
on some change of constitution consequent on the changed proportions and
relations of the functions. I will not dwell on the implication, which
seems tolerably clear, that this change must consist of such
modifications of organs as adapt them to their changed functions; and
that if the influence of changed conditions "accumulates," it must be
through the inheritance of such modifications. Nor will I press the
question--What is the nature of the effect registered in the
reproductive elements, and which is subsequently manifested by
variations?--Is it an effect entirely irrelevant to the new requirements
of the variety?--Or is it an effect which makes the variety less fit for
the new requirements?--Or is it an effect which makes it more fit for
the new requirements? But not pressing these questions, it suffices to
point out the necessary implication that changed functions of organs
_do_, in some way or other, register themselves in changed proclivities
of the reproductive elements. In face of these facts it cannot be denied
that the modified action of a part produces an inheritable effect--be
the nature of that effect what it may.

The second of the remarks above adverted to as made by Mr. Darwin, is
contained in his sections dealing with correlated variations. In the
_Origin of Species_, p. 114, he says--

     "The whole organization is so tied together during its growth and
     development, that when slight variations in any one part occur, and
     are accumulated through natural selection, other parts become
     modified."

And a parallel statement contained in _Animals and Plants under
Domestication_, vol. ii, p. 320, runs thus--

     "Correlated variation is an important subject for us; for when one
     part is modified through continued selection, either by man or
     under nature, other parts of the organization will be unavoidably
     modified. From this correlation it apparently follows that, with
     our domesticated animals and plants, varieties rarely or never
     differ from each other by some single character alone."

By what process does a changed part modify other parts? By modifying
their functions in some way or degree, seems the necessary answer. It is
indeed, imaginable, that where the part changed is some dermal appendage
which, becoming larger, has abstracted more of the needful material from
the general stock, the effect may consist simply in diminishing the
amount of this material available for other dermal appendages, leading
to diminution of some or all of them, and may fail to affect in
appreciable ways the rest of the organism: save perhaps the
blood-vessels near the enlarged appendage. But where the part is an
active one--a limb, or viscus, or any organ which constantly demands
blood, produces waste matter, secretes, or absorbs--then all the other
active organs become implicated in the change. The functions performed
by them have to constitute a moving equilibrium; and the function of one
cannot, by alteration of the structure performing it, be modified in
degree or kind, without modifying the functions of the rest--some
appreciably and others inappreciably, according to the directness or
indirectness of their relations. Of such inter-dependent changes, the
normal ones are naturally inconspicuous; but those which are partially
or completely abnormal, sufficiently carry home the general truth. Thus,
unusual cerebral excitement affects the excretion through the kidneys in
quantity or quality or both. Strong emotions of disagreeable kinds check
or arrest the flow of bile. A considerable obstacle to the circulation
offered by some important structure in a diseased or disordered state,
throwing more strain upon the heart, causes hypertrophy of its muscular
walls; and this change which is, so far as concerns the primary evil, a
remedial one, often entails mischiefs in other organs. "Apoplexy and
palsy, in a scarcely credible number of cases, are directly dependent on
hypertrophic enlargement of the heart." And in other cases, asthma,
dropsy, and epilepsy are caused. Now if a result of this
inter-dependence as seen in the individual organism, is that a local
modification of one part produces, by changing their functions,
correlative modifications of other parts, then the question here to be
put is--Are these correlative modifications, when of a kind falling
within normal limits, inheritable or not. If they are inheritable, then
the fact stated by Mr. Darwin that "when one part is modified through
continued selection," "other parts of the organization will be
unavoidably modified" is perfectly intelligible: these entailed
secondary modifications are transmitted _pari passu_ with the successive
modifications produced by selection. But what if they are not
inheritable? Then these secondary modifications caused in the
individual, not being transmitted to descendants, the descendants must
commence life with organizations out of balance, and with each increment
of change in the part affected by selection, their organizations must
get more out of balance--must have a larger and larger amounts of
re-organization to be made during their lives. Hence the constitution of
the variety must become more and more unworkable.

The only imaginable alternative is that the re-adjustments are effected
in course of time by natural selection. But, in the first place, as we
find no proof of concomitant variation among directly co-operative parts
which are closely united, there cannot be assumed any concomitant
variation among parts which are both indirectly co-operative and far
from one another. And, in the second place, before all the many
required re-adjustments could be made, the variety would die out from
defective constitution. Even were there no such difficulty, we should
still have to entertain a strange group of propositions, which would
stand as follows:--1. Change in one part entails, by reaction on the
organism, changes, in other parts, the functions of which are
necessarily changed. 2. Such changes worked in the individual, affect,
in some way, the reproductive elements: these being found to evolve
unusual structures when the constitutional balance has been continuously
disturbed. 3. But the changes in the reproductive elements thus caused,
are not such as represent these functionally-produced changes: the
modifications conveyed to offspring are irrelevant to these various
modifications functionally produced in the organs of the parents. 4.
Nevertheless, while the balance of functions cannot be re-established
through inheritance of the effects of disturbed functions on structures,
wrought throughout the individual organism; it can be re-established by
the inheritance of fortuitous variations which occur in all the affected
organs without reference to these changes of function.

Now without saying that acceptance of this group of propositions is
impossible, we may certainly say that it is not easy.

       *       *       *       *       *

"But where are the direct proofs that inheritance of
functionally-produced modifications takes place?" is a question which
will be put by those who have committed themselves to the current
exclusive interpretation. "Grant that there are difficulties; still,
before the transmitted effects of use and disuse can be legitimately
assigned in explanation of them, we must have good evidence that the
effects of use and disuse _are_ transmitted."

Before dealing directly with this demurrer, let me deal with it
indirectly, by pointing out that the lack of recognized evidence may be
accounted for without assuming that there is not plenty of it.
Inattention and reluctant attention lead to the ignoring of facts which
really exist in abundance; as is well illustrated in the case of
pre-historic implements. Biassed by the current belief that no traces of
man were to be found on the Earth's surface, save in certain superficial
formations of very recent date, geologists and anthropologists not only
neglected to seek such traces, but for a long time continued to
pooh-pooh those who said they had found them. When M. Boucher de Perthes
at length succeeded in drawing the eyes of scientific men to the flint
implements discovered by him in the quarternary deposits of the Somme
valley; and when geologists and anthropologists had thus been convinced
that evidences of human existence were to be found in formations of
considerable age, and thereafter began to search for them; they found
plenty of them all over the world. Or again, to take an instance closely
germane to the matter, we may recall the fact that the contemptuous
attitude towards the hypothesis of organic evolution which naturalists
in general maintained before the publication of Mr. Darwin's work,
prevented them from seeing the multitudinous facts by which it is
supported. Similarly, it is very possible that their alienation from the
belief that there is a transmission of those changes of structure which
are produced by changes of action, makes naturalists slight the evidence
which supports that belief and refuse to occupy themselves in seeking
further evidence.

If it be asked how it happens that there have been recorded
multitudinous instances of variations fortuitously arising and
re-appearing in offspring, while there have not been recorded instances
of the transmission of changes functionally produced, there are three
replies. The first is that changes of the one class are many of them
conspicuous, while those of the other class are nearly all
inconspicuous. If a child is born with six fingers, the anomaly is not
simply obvious but so startling as to attract much notice; and if this
child, growing up, has six-fingered descendents, everybody in the
locality hears of it. A pigeon with specially-coloured feathers, or one
distinguished by a broadened and upraised tail, or by a protuberance of
the neck, draws attention by its oddness; and if in its young the trait
is repeated, occasionally with increase, the fact is remarked, and there
follows the thought of establishing the peculiarity by selection. A lamb
disabled from leaping by the shortness of its legs, could not fail to be
observed; and the fact that its offspring were similarly short-legged,
and had a consequent inability to get over fences, would inevitably
become widely known. Similarly with plants. That this flower had an
extra number of petals, that that was unusually symmetrical, and that
another differed considerably in colour from the average of its kind,
would be easily seen by an observant gardener; and the suspicion that
such anomalies are inheritable having arisen, experiments leading to
further proofs that they are so, would frequently be made. But it is not
thus with functionally-produced modifications. The seats of these are in
nearly all cases the muscular, osseous, and nervous systems, and the
viscera--parts which are either entirely hidden or greatly obscured.
Modification in a nervous centre is inaccessible to vision; bones may be
considerably altered in size or shape without attention being drawn to
them; and, covered with thick coats as are most of the animals open to
continuous observation, the increases or decreases in muscles must be
great before they become externally perceptible.

A further important difference between the two inquiries is that to
ascertain whether a fortuitous variation is inheritable, needs merely a
little attention to the selection of individuals and the observation of
offspring; while to ascertain whether there is inheritance of a
functionally-produced modification, it is requisite to make arrangements
which demand the greater or smaller exercise of some part or parts;
and it is difficult in many cases to find such arrangements, troublesome
to maintain them even for one generation, and still more through
successive generations.

Nor is this all. There exist stimuli to inquiry in the one case which do
not exist in the other. The money-interest and the interest of the
fancier, acting now separately and now together, have prompted
multitudinous individuals to make experiments which have brought out
clear evidence that fortuitous variations are inherited. The
cattle-breeders who profit by producing certain shapes and qualities;
the keepers of pet animals who take pride in the perfections of those
they have bred; the florists, professional and amateur, who obtain new
varieties and take prizes; form a body of men who furnish naturalists
with countless of the required proofs. But there is no such body of men,
led either by pecuniary interest or the interest of a hobby, to
ascertain by experiments whether the effects of use and disuse are
inheritable.

Thus, then, there are amply sufficient reasons why there is a great deal
of direct evidence in the one case and but little in the other: such
little being that which comes out incidentally. Let us look at what
there is of it.

       *       *       *       *       *

Considerable weight attaches to a fact which Brown-Séquard discovered,
quite by accident, in the course of his researches. He found that
certain artificially-produced lesions of the nervous system, so small
even as a section of the sciatic nerve, left, after healing, an
increasing excitability which ended in liability to epilepsy; and there
afterwards came out the unlooked-for result that the offspring of
guinea-pigs which had thus acquired an epileptic habit such that a pinch
on the neck would produce a fit, inherited an epileptic habit of like
kind. It has, indeed, been since alleged that guinea pigs tend to
epilepsy, and that phenomena of the kind described, occur where there
have been no antecedents like those in Brown-Séquard's case. But
considering the improbability that the phenomena observed by him
happened to be nothing more than phenomena which occasionally arise
naturally, we may, until there is good proof to the contrary, assign
some value to his results.

Evidence not of this directly experimental kind, but nevertheless of
considerable weight, is furnished by other nervous disorders. There is
proof enough that insanity admits of being induced by circumstances
which, in one or other way, derange the nervous functions--excesses of
this or that kind; and no one questions the accepted belief that
insanity is inheritable. Is it alleged that the insanity which is
inheritable is that which spontaneously arises, and that the insanity
which follows some chronic perversion of functions is not inheritable?
This does not seem a very reasonable allegation; and until some warrant
for it is forthcoming, we may fairly assume that there is here a further
support for belief in the transmission of functionally-produced changes.

Moreover, I find among physicians the belief that nervous disorders of a
less severe kind are inheritable. Men who have prostrated their nervous
systems by prolonged overwork or in some other way, have children more
or less prone to nervousness. It matters not what may be the form of
inheritance--whether it be of a brain in some way imperfect, or of a
deficient blood-supply; it is in any case the inheritance of
functionally-modified structures.

Verification of the reasons above given for the paucity of this direct
evidence, is yielded by contemplation of it; for it is observable that
the cases named are cases which, from one or other cause, have thrust
themselves on observation. They justify the suspicion that it is not
because such cases are rare that many of them cannot be cited; but
simply because they are mostly unobtrusive, and to be found only by that
deliberate search which nobody makes. I say nobody, but I am wrong.
Successful search has been made by one whose competence as an observer
is beyond question, and whose testimony is less liable than that of all
others to any bias towards the conclusion that such inheritance takes
place. I refer to the author of the _Origin of Species_.

       *       *       *       *       *

Now-a-days most naturalists are more Darwinian than Mr. Darwin himself.
I do not mean that their beliefs in organic evolution are more decided;
though I shall be supposed to mean this by the mass of readers, who
identify Mr. Darwin's great contribution to the theory of organic
evolution, with the theory of organic evolution itself, and even with
the theory of evolution at large. But I mean that the particular factor
which he first recognized as having played so immense a part in organic
evolution, has come to be regarded by his followers as the sole factor,
though it was not so regarded by him. It is true that he apparently
rejected altogether the causal agencies alleged by earlier inquirers. In
the Historical Sketch prefixed to the later editions of his _Origin of
Species_ (p. xiv, note), he writes:--"It is curious how largely my
grandfather, Dr. Erasmus Darwin, anticipated the views and erroneous
grounds of opinion of Lamarck in his 'Zoonomia' (vol. i, pp. 500-510),
published in 1794." And since, among the views thus referred to, was the
view that changes of structure in organisms arise by the inheritance of
functionally-produced changes, Mr. Darwin seems, by the above sentence,
to have implied his disbelief in such inheritance. But he did not mean
to imply this; for his belief in it as a cause of evolution, if not an
important cause, is proved by many passages in his works. In the first
chapter of the _Origin of Species_ (p. 8 of the sixth edition), he says
respecting the inherited effects of habit, that "with animals the
increased use or disuse of parts has had a more marked influence;" and
he gives as instances the changed relative weights of the wing bones and
leg bones of the wild duck and the domestic duck, "the great and
inherited development of the udders in cows and goats," and the drooping
ears of various domestic animals. Here are other passages taken from the
latest edition of the work.

     "I think there can be no doubt that use in our domestic animals has
     strengthened and enlarged certain parts, and disuse diminished
     them; and that such modifications are inherited" (p. 108). [And on
     the following pages he gives five further examples of such
     effects.] "Habit in producing constitutional peculiarities and use
     in strengthening and disuse in weakening and diminishing organs,
     appear in many cases to have been potent in their effects" (p.
     131). "When discussing special cases, Mr. Mivart passes over the
     effects of the increased use and disuse of parts, which I have
     always maintained to be highly important, and have treated in my
     'Variation under Domestication' at greater length than, as I
     believe, any other writer" (p. 176). "Disuse, on the other hand,
     will account for the less developed condition of the whole inferior
     half of the body, including the lateral fins" (p. 188). "I may give
     another instance of a structure which apparently owes its origin
     exclusively to use or habit" (p. 188). "It appears probable that
     disuse has been the main agent in rendering organs rudimentary"
     (pp. 400-401). "On the whole, we may conclude that habit, or use
     and disuse, have, in some cases, played a considerable part in the
     modification of the constitution and structure; but that the
     effects have often been largely combined with, and sometimes
     overmastered by, the natural selection of innate variations" (p.
     114).

In his subsequent work, _The Variation of Animals and Plants under
Domestication_, where he goes into full detail, Mr. Darwin gives more
numerous illustrations of the inherited effects of use and disuse. The
following are some of the cases, quoted from volume i of the first
edition.

     Treating of domesticated rabbits, he says:--"the want of exercise
     has apparently modified the proportional length of the limbs in
     comparison with the body" (p. 116). "We thus see that the most
     important and complicated organ [the brain] in the whole
     organization is subject to the law of decrease in size from disuse"
     (p. 129). He remarks that in birds of the oceanic islands "not
     persecuted by any enemies, the reduction of their wings has
     probably been caused by gradual disuse." After comparing one of
     these, the water-hen of Tristan d'Acunha, with the European
     water-hen, and showing that all the bones concerned in flight are
     smaller, he adds--"Hence in the skeleton of this natural species
     nearly the same changes have occurred, only carried a little
     further, as with our domestic ducks, and in this latter case I
     presume no one will dispute that they have resulted from the
     lessened use of the wings and the increased use of the legs" (pp.
     286-7). "As with other long-domesticated animals, the instincts of
     the silk-moth have suffered. The caterpillars, when placed on a
     mulberry-tree, often commit the strange mistake of devouring the
     base of the leaf on which they are feeding, and consequently fall
     down; but they are capable, according to M. Robinet, of again
     crawling up the trunk. Even this capacity sometimes fails, for M.
     Martins placed some caterpillars on a tree, and those which fell
     were not able to remount and perished of hunger; they were even
     incapable of passing from leaf to leaf" (p. 304).

Here are some instances of like meaning from volume ii.

     "In many cases there is reason to believe that the lessened use of
     various organs has affected the corresponding parts in the
     offspring. But there is no good evidence that this ever follows in
     the course of a single generation.... Our domestic fowls, ducks,
     and geese have almost lost, not only in the individual but in the
     race, their power of flight; for we do not see a chicken, when
     frightened, take flight like a young pheasant.... With domestic
     pigeons, the length of the sternum, the prominence of its crest,
     the length of the scapulæ and furcula, the length of the wings as
     measured from tip to tip of the radius, are all reduced relatively
     to the same parts in the wild pigeon." [After detailing kindred
     diminutions in fowls and ducks, Mr. Darwin adds] "The decreased
     weight and size of the bones, in the foregoing cases, is probably
     the indirect result of the reaction of the weakened muscles on the
     bones" (pp. 297-8). "Nathusius has shown that, with the improved
     races of the pig, the shortened legs and snout, the form of the
     articular condyles of the occiput, and the position of the jaws
     with the upper canine teeth projecting in a most anomalous manner
     in front of the lower canines, may be attributed to these parts not
     having been fully exercised.... These modifications of structure,
     which are all strictly inherited, characterise several improved
     breeds, so that they cannot have been derived from any single
     domestic or wild stock. With respect to cattle, Professor Tanner
     has remarked that the lungs and liver in the improved breeds 'are
     found to be considerably reduced in size when compared with those
     possessed by animals having perfect liberty;' ... The cause of the
     reduced lungs in highly-bred animals which take little exercise is
     obvious" (pp. 299-300). [And on pp. 301, 302 and 303, he gives
     facts showing the effects of use and disuse in changing, among
     domestic animals, the characters of the ears, the lengths of the
     intestines, and, in various ways, the natures of the instincts.]

But Mr. Darwin's admission, or rather his assertion, that the
inheritance of functionally-produced modifications has been a factor in
organic evolution, is made clear not by these passages alone and by
kindred ones. It is made clearer still by a passage in the preface to
the second edition of his _Descent of Man_. He there protests against
that current version of his views in which this factor makes no
appearance. The passage is as follows.

     "I may take this opportunity of remarking that my critics
     frequently assume that I attribute all changes of corporeal
     structure and mental power exclusively to the natural selection of
     such variations as are often called spontaneous; whereas, even in
     the first edition of the 'Origin of Species,' I distinctly stated
     that great weight must be attributed to the inherited effects of
     use and disuse, with respect both to the body and mind."

Nor is this all. There is evidence that Mr. Darwin's belief in the
efficiency of this factor, became stronger as he grew older and
accumulated more evidence. The first of the extracts above given, taken
from the sixth edition of the _Origin of Species_, runs thus:--

     "I think there can be no doubt that use in our domestic animals has
     strengthened and enlarged certain parts, and disuse diminished
     them; and that such modifications are inherited."

Now on turning to the first edition, p. 134, it will be found that
instead of the words--"I think there can be no doubt," the words
originally used were--"I think there can be _little_ doubt." That this
deliberate erasure of a qualifying word and substitution of a word
implying unqualified belief, was due to a more decided recognition of a
factor originally under-estimated, is clearly implied by the wording of
the above-quoted passage from the preface to the _Descent of Man_; where
he says that "_even_ in the first edition of the 'Origin of Species,'"
&c.: the implication being that much more in subsequent editions, and
subsequent works, had he insisted on this factor. The change thus
indicated is especially significant as having occurred at a time of life
when the natural tendency is towards fixity of opinion.

During that earlier period when he was discovering the multitudinous
cases in which his own hypothesis afforded solutions, and simultaneously
observing how utterly futile in these multitudinous cases was the
hypothesis propounded by his grandfather and Lamarck, Mr. Darwin was,
not unnaturally, almost betrayed into the belief that the one is
all-sufficient and the other inoperative. But in the mind of one so
candid and ever open to more evidence, there naturally came a reaction.
The inheritance of functionally-produced modifications, which, judging
by the passage quoted above concerning the views of these earlier
enquirers, would seem to have been at one time denied, but which as we
have seen was always to some extent recognized, came to be recognized
more and more, and deliberately included as a factor of importance.

       *       *       *       *       *

Of this reaction displayed in the later writings of Mr. Darwin, let us
now ask--Has it not to be carried further? Was the share in organic
evolution which Mr. Darwin latterly assigned to the transmission of
modifications caused by use and disuse, its due share? Consideration of
the groups of evidences given above, will, I think, lead us to believe
that its share has been much larger than he supposed even in his later
days.

There is first the implication yielded by extensive classes of phenomena
which remain inexplicable in the absence of this factor. If, as we see,
co-operative parts do not vary together, even when few and close
together, and may not therefore be assumed to do so when many and
remote, we cannot account for those innumerable changes in organization
which are implied when, for advantageous use of some modified part, many
other parts which join it in action have to be modified.

Further, as increasing complexity of structure, accompanying increasing
complexity of life, implies increasing number of faculties, of which
each one conduces to preservation of self or descendants; and as the
various individuals of a species, severally requiring something like the
normal amounts of all these, may individually profit, here by an unusual
amount of one, and there by an unusual amount of another; it follows
that as the number of faculties becomes greater, it becomes more
difficult for any one to be further developed by natural selection. Only
where increase of some one is _predominantly_ advantageous does the
means seem adequate to the end. Especially in the case of powers which
do not subserve self-preservation in appreciable degrees, does
development by natural selection appear impracticable.

It is a fact recognized by Mr. Darwin, that where, by selection through
successive generations, a part has been increased or decreased, its
reaction upon other parts entails changes in them. This reaction is
effected through the changes of function involved. If the changes of
structure produced by such changes of function, are inheritable, then
the re-adjustment of parts throughout the organism, taking place
generation after generation, maintains an approximate balance; but if
not, then generation after generation the organism must get more and
more out of gear, and tend to become unworkable.

Further, as it is proved that change in the balance of functions
registers its effects on the reproductive elements, we have to choose
between the alternatives that the registered effects are irrelevant to
the particular modifications which the organism has undergone, or that
they are such as tend to produce repetitions of these modifications. The
last of these alternatives makes the facts comprehensible; but the first
of them not only leaves us with several unsolved problems, but is
incongruous with the general truth that by reproduction, ancestral
traits, down to minute details, are transmitted.

Though, in the absence of pecuniary interests and the interests in
hobbies, no such special experiments as those which have established the
inheritance of fortuitous variations have been made to ascertain whether
functionally-produced modifications are inherited; yet certain apparent
instances of such inheritance have forced themselves on observation
without being sought for. In addition to other indications of a less
conspicuous kind, is the one I have given above--the fact that the
apparatus for tearing and mastication has decreased with decrease of its
function, alike in civilized man and in some varieties of dogs which
lead protected and pampered lives. Of the numerous cases named by Mr.
Darwin, it is observable that they are yielded not by one class of parts
only, but by most if not all classes--by the dermal system, the muscular
system, the osseous system, the nervous system, the viscera; and that
among parts liable to be functionally modified, the most numerous
observed cases of inheritance are furnished by those which admit of
preservation and easy comparison--the bones: these cases, moreover,
being specially significant as showing how, in sundry unallied species,
parallel changes of structure have occurred along with parallel changes
of habit.

What, then, shall we say of the general implication? Are we to stop
short with the admission that inheritance of functionally-produced
modifications takes place only in cases in which there is evidence of
it? May we properly assume that these many instances of changes of
structure caused by changes of function, occurring in various tissues
and various organs, are merely special and exceptional instances having
no general significance? Shall we suppose that though the evidence which
already exists has come to light without aid from a body of inquirers,
there would be no great increase were due attention devoted to the
collection of evidence? This is, I think, not a reasonable supposition.
To me the _ensemble_ of the facts suggests the belief, scarcely to be
resisted, that the inheritance of functionally-produced modifications
takes place universally. Looking at physiological phenomena as
conforming to physical principles, it is difficult to conceive that a
changed play of organic forces which in many cases of different kinds
produces an inherited change of structure, does not do this in all
cases. The implication, very strong I think, is that the action of every
organ produces on it a reaction which, usually not altering its rate of
nutrition, sometimes leaves it with diminished nutrition consequent on
diminished action, and at other times increases its nutrition in
proportion to its increased action; that while generating a modified
_consensus_ of functions and of structures, the activities are at the
same time impressing this modified _consensus_ on the sperm-cells and
germ-cells whence future individuals are to be produced; and that in
ways mostly too small to be identified, but occasionally in more
conspicuous ways and in the course of generations, the resulting
modifications of one or other kind show themselves. Further, it seems to
me that as there are certain extensive classes of phenomena which are
inexplicable if we assume the inheritance of fortuitous variations to be
the sole factor, but which become at once explicable if we admit the
inheritance of functionally-produced changes, we are justified in
concluding that this inheritance of functionally-produced changes has
been not simply a co-operating factor in organic evolution, but has been
a co-operating factor without which organic evolution, in its higher
forms at any rate, could never have taken place.

Be this or be it not a warrantable conclusion, there is, I think, good
reason for a provisional acceptance of the hypothesis that the effects
of use and disuse are inheritable; and for a methodic pursuit of
inquiries with the view of either establishing it or disproving it. It
seems scarcely reasonable to accept without clear demonstration, the
belief that while a trivial difference of structure arising
spontaneously is transmissible, a massive difference of structure,
maintained generation after generation by change of function, leaves no
trace in posterity. Considering that unquestionably the modification of
structure by function is a _vera causa_, in so far as concerns the
individual; and considering the number of facts which so competent an
observer as Mr. Darwin regarded as evidence that transmission of such
modifications takes place in particular cases; the hypothesis that such
transmission takes place in conformity with a general law, holding of
all active structures, should, I think, be regarded as at least a good
working hypothesis.

       *       *       *       *       *

But now supposing the broad conclusion above drawn to be
granted--supposing all to agree that from the beginning, along with
inheritance of useful variations fortuitously arising, there has been
inheritance of effects produced by use and disuse; do there remain no
classes of organic phenomena unaccounted for? To this question I think
it must be replied that there do remain classes of organic phenomena
unaccounted for. It may, I believe, be shown that certain cardinal
traits of animals and plants at large are still unexplained; and that a
further factor must be recognized. To show this, however, will require
another paper.


II.

Ask a plumber who is repairing your pump, how the water is raised in it,
and he replies--"By suction." Recalling the ability which he has to suck
up water into his mouth through a tube, he is certain that he
understands the pump's action. To inquire what he means by suction,
seems to him absurd. He says you know as well as he does, what he means;
and he cannot see that there is any need for asking how it happens that
the water rises in the tube when he strains his mouth in a particular
way. To the question why the pump, acting by suction, will not make the
water rise above 32 feet, and practically not so much, he can give no
answer; but this does not shake his confidence in his explanation.

On the other hand an inquirer who insists on knowing what suction is,
may obtain from the physicist answers which give him clear ideas, not
only about it but about many other things. He learns that on ourselves
and all things around, there is an atmospheric pressure amounting to
about 15 pounds on the square inch: 15 pounds being the average weight
of a column of air having a square inch for its base and extending
upwards from the sea-level to the limit of the Earth's atmosphere. He is
made to observe that when he puts one end of a tube into water and the
other end into his mouth, and then draws back his tongue, so leaving a
vacant space, two things happen. One is that the pressure of air outside
his cheeks, no longer balanced by an equal pressure of air inside,
thrusts his cheeks inwards; and the other is that the pressure of air on
the surface of the water, no longer balanced by an equal pressure of air
within the tube and his mouth (into which part of the air from the tube
has gone) the water is forced up the tube in consequence of the unequal
pressure. Once understanding thus the nature of the so-called suction,
he sees how it happens that when the plunger of the pump is raised and
relieves from atmospheric pressure the water below it, the atmospheric
pressure on the water in the well, not being balanced by that on the
water in the tube, forces the water higher up the tube, so that it
follows the plunger. And now he sees why the water cannot be raised
beyond the theoretic limit of 32 feet: a limit made much lower in
practice by imperfections in the apparatus. For if, simplifying the
conception, he supposes the tube of the pump to be a square inch in
section, then the atmospheric pressure of 15 pounds per square inch on
the water in the well, can raise the water in the tube to such height
only that the entire column of it weighs 15 pounds. Having been thus
enlightened about the pump's action, the action of a barometer becomes
intelligible. He perceives how, under the conditions established, the
weight of the column of mercury balances that of an atmospheric column
of equal diameter; and how, as the weight of the atmospheric column
varies, there is a corresponding variation in the weight of the
mercurial column,--shown by change of height. Moreover, having
previously supposed that he understood the ascent of a balloon when he
ascribed it to relative lightness, he now sees that he did not truly
understand it. For he did not recognize it as a result of that upward
pressure caused by the difference between the weight of the mass formed
by the gas in the balloon _plus_ the cylindrical column of air extending
above it to the limit of the atmosphere, and the weight of a similar
cylindrical column of air extending down to the under surface of the
balloon: this difference of weight causing an equivalent upward pressure
on the under surface.

Why do I introduce these familiar truths so entirely irrelevant to my
subject? I do it to show, in the first place, the contrast between a
vague conception of a cause and a distinct conception of it; or rather,
the contrast between that conception of a cause which results when it is
simply classed with some other or others which familiarity makes us
think we understand, and that conception of a cause which results when
it is represented in terms of definite physical forces admitting of
measurement. And I do it to show, in the second place, that when we
insist on resolving a verbally-intelligible cause into its actual
factors, we get not only a clear solution of the problem before us, but
we find that the way is opened to solutions of sundry other problems.
While we rest satisfied with unanalyzed causes, we may be sure both that
we do not rightly comprehend the production of the particular effects
ascribed to them, and that we overlook other effects which would be
revealed to us by contemplation of the causes as analyzed. Especially
must this be so where the causation is complex. Hence we may infer that
the phenomena presented by the development of species, are not likely to
be truly conceived unless we keep in view the concrete agencies at work.
Let us look closely at the facts to be dealt with.

       *       *       *       *       *

The growth of a thing is effected by the joint operation of certain
forces on certain materials; and when it dwindles, there is either a
lack of some materials, or the forces co-operate in a way different from
that which produces growth. If a structure has varied, the implication
is that the processes which built it up were made unlike the parallel
processes in other cases, by the greater or less amount of some one or
more of the matters or actions concerned. Where there is unusual
fertility, the play of vital activities is thereby shown to have
deviated from the ordinary play of vital activities; and conversely, if
there is infertility. If the germs, or ova, or seed, or offspring
partially developed, survive more or survive less, it is either because
their molar or molecular structures are unlike the average ones, or
because they are affected in unlike ways by surrounding agencies. When
life is prolonged, the fact implies that the combination of actions,
visible and invisible, constituting life, retains its equilibrium longer
than usual in presence of environing forces which tend to destroy its
equilibrium. That is to say, growth, variation, survival, death, if they
are to be reduced to the forms in which physical science can recognize
them, must be expressed as effects of agencies definitely
conceived--mechanical forces, light, heat, chemical affinity, &c.

This general conclusion brings with it the thought that the phrases
employed in discussing organic evolution, though convenient and indeed
needful, are liable to mislead us by veiling the actual agencies. That
which really goes on in every organism is the working together of
component parts in ways conducing to the continuance of their combined
actions, in presence of things and actions outside; some of which tend
to subserve, and others to destroy, the combination. The matters and
forces in these two groups, are the sole causes properly so called. The
words "natural selection," do not express a cause in the physical sense.
They express a mode of co-operation among causes--or rather, to speak
strictly, they express an effect of this mode of co-operation. The idea
they convey seems perfectly intelligible. Natural selection having been
compared with artificial selection, and the analogy pointed out, there
apparently remains no indefiniteness: the inconvenience being, however,
that the definiteness is of a wrong kind. The tacitly implied Nature
which selects, is not an embodied agency analogous to the man who
selects artificially; and the selection is not the picking out of an
individual fixed on, but the overthrowing of many individuals by
agencies which one successfully resists, and hence continues to live and
multiply. Mr. Darwin was conscious of these misleading implications. In
the introduction to his _Animals and Plants under Domestication_ (p. 6)
he says:--

     "For brevity sake I sometimes speak of natural selection as an
     intelligent power; ... I have, also, often personified the word
     Nature; for I have found it difficult to avoid this ambiguity; but
     I mean by nature only the aggregate action and product of many
     natural laws,--and by laws only the ascertained sequence of
     events."

But while he thus clearly saw, and distinctly asserted, that the factors
of organic evolution are the concrete actions, inner and outer, to which
every organism is subject, Mr. Darwin, by habitually using the
convenient figure of speech, was, I think, prevented from recognizing so
fully as he would otherwise have done, certain fundamental consequences
of these actions.

Though it does not personalize the cause, and does not assimilate its
mode of working to a human mode of working, kindred objections may be
urged against the expression to which I was led when seeking to present
the phenomena in literal terms rather than metaphorical terms--the
survival of the fittest;[42] for in a vague way the first word, and in a
clear way the second word, calls up an anthropocentric idea. The
thought of survival inevitably suggests the human view of certain sets
of phenomena, rather than that character which they have simply as
groups of changes. If, asking what we really know of a plant, we exclude
all the ideas associated with the words life and death, we find that the
sole facts known to us are that there go on in the plant certain
inter-dependent processes, in presence of certain aiding and hindering
influences outside of it; and that in some cases a difference of
structure or a favourable set of circumstances, allows these
inter-dependent processes to go on for longer periods than in other
cases. Again, in the working together of those many actions, internal
and external, which determine the lives or deaths of organisms, we see
nothing to which the words fitness and unfitness are applicable in the
physical sense. If a key fits a lock, or a glove a hand, the relation of
the things to one another is presentable to the perceptions. No approach
to fitness of this kind is made by an organism which continues to live
under certain conditions. Neither the organic structures themselves, nor
their individual movements, nor those combined movements of certain
among them which constitute conduct, are related in any analogous way to
the things and actions in the environment. Evidently the word fittest,
as thus used, is a figure of speech; suggesting the fact that amid
surrounding actions, an organism characterized by the word has either a
greater ability than others of its kind to maintain the equilibrium of
its vital activities, or else has so much greater a power of
multiplication that though not longer lived than they, it continues to
live in posterity more persistently. And indeed, as we here see, the
word fittest has to cover cases in which there may be less ability than
usual to survive individually, but in which the defect is more than made
good by higher degrees of fertility.

I have elaborated this criticism with the intention of emphasizing the
need for studying the changes which have gone on, and are ever going
on, in organic bodies, from an exclusively physical point of view. On
contemplating the facts from this point of view, we become aware that,
besides those special effects of the co-operating forces which eventuate
in the longer survival of one individual than of others, and in the
consequent increase through generations, of some trait which furthered
its survival, many other effects are being wrought on each and all of
the individuals. Bodies of every class and quality, inorganic as well as
organic, are from instant to instant subject to the influences in their
environments; are from instant to instant being changed by these in ways
that are mostly inconspicuous; and are in course of time changed by them
in conspicuous ways. Living things in common with dead things, are, I
say, being thus perpetually acted upon and modified; and the changes
hence resulting, constitute an all-important part of those undergone in
the course of organic evolution. I do not mean to imply that changes of
this class pass entirely unrecognized; for, as we shall see, Mr. Darwin
takes cognizance of certain secondary and special ones. But the effects
which are not taken into account, are those primary and universal
effects which give certain fundamental characters to all organisms.
Contemplation of an analogy will best prepare the way for appreciation
of them, and of the relation they bear to those which at present
monopolize attention.

An observant rambler along shores, will, here and there, note places
where the sea has deposited things more or less similar, and separated
them from dissimilar things--will see shingle parted from sand; larger
stones sorted from smaller stones; and will occasionally discover
deposits of shells more or less worn by being rolled about. Sometimes
the pebbles or boulders composing the shingle at one end of a bay, he
will find much larger than those at the other: intermediate sizes,
having small average differences, occupying the space between the
extremes. An example occurs, if I remember rightly, some mile or two to
the west of Tenby; but the most remarkable and well-known example is
that afforded by the Chesil bank. Here, along a shore some sixteen miles
long, there is a gradual increase in the sizes of the stones; which,
being at one end but mere pebbles, are at the other end immense
boulders. In this case, then, the breakers and the undertow have
effected a selection--have at each place left behind those stones which
were too large to be readily moved, while taking away others small
enough to be moved easily. But now, if we contemplate exclusively this
selective action of the sea, we overlook certain important effects which
the sea simultaneously works. While the stones have been differently
acted upon in so far that some have been left here and some carried
there; they have been similarly acted upon in two allied, but
distinguishable, ways. By perpetually rolling them about and knocking
them one against another, the waves have so broken off their most
prominent parts as to produce in all of them more or less rounded forms;
and then, further, the mutual friction of the stones simultaneously
caused, has smoothed their surfaces. That is to say in general terms,
the actions of environing agencies, so far as they have operated
indiscriminately, have produced in the stones a certain unity of
character; at the same time that they have, by their differential
effects, separated them: the larger ones having withstood certain
violent actions which the smaller ones could not withstand.

Similarly with other assemblages of objects which are alike in their
primary traits but unlike in their secondary traits. When simultaneously
exposed to the same set of actions, some of these actions, rising to a
certain intensity, may be expected to work on particular members of the
assemblage changes which they cannot work in those which are markedly
unlike; while others of the actions will work in all of them similar
changes, because of the uniform relations between these actions and
certain attributes common to all members of the assemblage. Hence it is
inferable that on living organisms, which form an assemblage of this
kind, and are unceasingly exposed in common to the agencies composing
their inorganic environments, there must be wrought two such sets of
effects. There will result a universal likeness among them consequent on
the likeness of their respective relations to the matters and forces
around; and there will result, in some cases, the differences due to the
differential effects of these matters and forces, and in other cases,
the changes which, being life-sustaining or life-destroying, eventuate
in certain natural selections.

I have, above, made a passing reference to the fact that Mr. Darwin did
not fail to take account of some among these effects directly produced
on organisms by surrounding inorganic agencies. Here are extracts from
the sixth edition of the _Origin of Species_ showing this.

     "It is very difficult to decide how far changed conditions, such as
     of climate, food, &c., have acted in a definite manner. There is
     reason to believe that in the course of time the effects have been
     greater than can be proved by clear evidence.... Mr. Gould believes
     that birds of the same species are more brightly coloured under a
     clear atmosphere, than when living near the coast or on islands;
     and Wollaston is convinced that residence near the sea affects the
     colours of insects. Moquin-Tandon gives a list of plants which,
     when growing near the sea-shore, have their leaves in some degree
     fleshy, though not elsewhere fleshy" (pp. 106-7). "Some observers
     are convinced that a damp climate affects the growth of the hair,
     and that with the hair the horns are correlated" (p. 159).

In his subsequent work, _Animals and Plants under Domestication_, Mr.
Darwin still more clearly recognizes these causes of change in
organization. A chapter is devoted to the subject. After premising that
"the direct action of the conditions of life, whether leading to
definite or indefinite results, is a totally distinct consideration from
the effects of natural selection;" he goes on to say that changed
conditions of life "have acted so definitely and powerfully on the
organisation of our domesticated productions, that they have sufficed
to form new sub-varieties or races, without the aid of selection by man
or of natural selection." Of his examples here are two.

     "I have given in detail in the ninth chapter the most remarkable
     case known to me, namely, that in Germany several varieties of
     maize brought from the hotter parts of America were transformed in
     the course of only two or three generations." (Vol. ii, p. 277.)
     [And in this ninth chapter concerning these and other such
     instances he says "some of the foregoing differences would
     certainly be considered of specific value with plants in a state of
     nature." (Vol. i, p. 321.)] "Mr. Meehan, in a remarkable paper,
     compares twenty-nine kinds of American trees, belonging to various
     orders, with their nearest European allies, all grown in close
     proximity in the same garden and under as nearly as possible the
     same conditions." And then enumerating six traits in which the
     American forms all of them differ in like ways from their allied
     European forms, Mr. Darwin thinks there is no choice but to
     conclude that these "have been definitely caused by the
     long-continued action of the different climate of the two
     continents on the trees." (Vol. ii, pp. 281-2.)

But the fact we have to note is that while Mr. Darwin thus took account
of special effects due to special amounts and combinations of agencies
in the environment, he did not take account of the far more important
effects due to the general and constant operation of these agencies.[43]
If a difference between the quantities of a force which acts on two
organisms, otherwise alike and otherwise similarly conditioned, produces
some difference between them; then, by implication, this force produces
in both of them effects which they show in common. The inequality
between two things cannot have a value unless the things themselves have
values. Similarly if, in two cases, some unlikeness of proportion among
the surrounding inorganic agencies to which two plants or two animals
are exposed, is followed by some unlikeness in the changes wrought on
them; then it follows that these several agencies taken separately, work
changes in both of them. Hence we must infer that organisms have certain
structural characters in common, which are consequent on the action of
the medium in which they exist: using the word medium in a comprehensive
sense, as including all physical forces falling upon them as well as
matters bathing them. And we may conclude that from the primary
characters thus produced there must result secondary characters.

Before going on to observe those general traits of organisms due to the
general action of the inorganic environment upon them, I feel tempted to
enlarge on the effects produced by each of the several matters and
forces constituting the environment. I should like to do this not only
to give a clear preliminary conception of the ways in which all
organisms are affected by these universally-present agents, but also to
show that, in the first place, these agents modify inorganic bodies as
well as organic bodies, and that, in the second place, the organic are
far more modifiable by them than the inorganic. But to avoid undue
suspension of the argument, I content myself with saying that when the
respective effects of gravitation, heat, light, &c., are studied, as
well as the respective effects, physical and chemical, of the matters
forming the media, water and air, it will be found that while more or
less operative on all bodies, each modifies organic bodies to an extent
immensely greater than the extent to which it modifies inorganic bodies.

       *       *       *       *       *

Here, not discriminating among the special effects which these various
forces and matters in the environment produce on both classes of bodies,
let us consider their combined effects, and ask--What is the most
general trait of such effects?

Obviously the most general trait is the greater amount of change wrought
on the outer surface than on the inner mass. In so far as the matters of
which the medium is composed come into play, the unavoidable implication
is that they act more on the parts directly exposed to them than on the
parts sheltered from them. And in so far as the forces pervading the
medium come into play, it is manifest that, excluding gravity, which
affects outer and inner parts indiscriminately, the outer parts have to
bear larger shares of their actions. If it is a question of heat, then
the exterior must lose it or gain it faster than the interior; and in a
medium which is now warmer and now colder, the two must habitually
differ in temperature to some extent--at least where the size is
considerable. If it is a question of light, then in all but absolutely
transparent masses, the outer parts must undergo more of any change
producible by it than the inner parts--supposing other things equal; by
which I mean, supposing the case is not complicated by any such
convexities of the outer surface as produce internal concentrations of
rays. Hence then, speaking generally, the necessity is that the primary
and almost universal effect of the converse between the body and its
medium, is to differentiate its outside from its inside. I say almost
universal, because where the body is both mechanically and chemically
stable, like, for instance, a quartz crystal, the medium may fail to
work either inner or outer change.

Of illustrations among inorganic bodies, a convenient one is supplied by
an old cannon-ball that has been long lying exposed. A coating of rust,
formed of flakes within flakes, incloses it; and this thickens year by
year, until, perhaps, it reaches a stage at which its exterior loses as
much by rain and wind as its interior gains by further oxidation of the
iron. Most mineral masses--pebbles, boulders, rocks--if they show any
effect of the environment at all, show it only by that disintegration of
surface which follows the freezing of absorbed water: an effect which,
though mechanical rather than chemical, equally illustrates the general
truth. Occasionally a "rocking-stone" is thus produced. There are formed
successive layers relatively friable in texture, each of which, thickest
at the most exposed parts, and being presently lost by weathering,
leaves the contained mass in a shape more rounded than before; until,
resting on its convex under-surface, it is easily moved. But of all
instances perhaps the most remarkable is one to be seen on the west bank
of the Nile at Philæ, where a ridge of granite 100 feet high, has had
its outer parts reduced in course of time to a collection of
boulder-shaped masses, varying from say a yard in diameter to six or
eight feet, each one of which shows in progress an exfoliation of
successively-formed shells of decomposed granite: most of the masses
having portions of such shells partially detached.

If, now, inorganic masses, relatively so stable in composition, thus
have their outer parts differentiated from their inner parts, what must
we say of organic masses, characterized by such extreme chemical
instability?--instability so great that their essential material is
named protein, to indicate the readiness with which it passes from one
isomeric form to another. Clearly the necessary inference is that this
effect of the medium must be wrought inevitably and promptly, wherever
the relation of outer and inner has become settled: a qualification for
which the need will be seen hereafter.

       *       *       *       *       *

Beginning with the earliest and most minute kinds of living things, we
necessarily encounter difficulties in getting direct evidence; since, of
the countless species now existing, all have been subject during
millions upon millions of years to the evolutionary process, and have
had their primary traits complicated and obscured by those endless
secondary traits which the natural selection of favourable variations
has produced. Among protophytes it needs but to think of the
multitudinous varieties of diatoms and desmids, with their
elaborately-constructed coverings; or of the definite methods of growth
and multiplication among such simple _Algæ_ as the _Conjugatæ_; to see
that most of their distinctive characters are due to inherited
constitutions, which have been slowly moulded by survival of the fittest
to this or that mode of life. To disentangle such parts of their
developmental changes as are due to the action of the medium, is
therefore hardly possible. We can hope only to get a general conception
of it by contemplating the totality of the facts.

The first cardinal fact is that all protophytes are cellular--all show
us this contrast between outside and inside. Supposing the multitudinous
specialities of the envelope in different orders and genera of
protophytes to be set against one another, and mutually cancelled, there
remains as a trait common to them--an envelope unlike that which it
envelopes. The second cardinal fact is that this simple trait is the
earliest trait displayed in germs, or spores, or other parts from which
new individuals are to arise; and that, consequently, this trait must be
regarded as having been primordial. For it is an established truth of
organic evolution that embryos show us, in general ways, the forms of
remote ancestors; and that the first changes undergone, indicate, more
or less clearly, the first changes which took place in the series of
forms through which the existing form has been reached. Describing, in
successive groups of plants, the early transformations of these
primitive units, Sachs[44] says of the lowest _Algæ_ that "the
conjugated protoplasmic body clothes itself with a cell-wall" (p. 10);
that in "the spores of Mosses and Vascular Cryptogams" and in "the
pollen of Phanerogams" ... "the protoplasmic body of the mother-cell
breaks up into four lumps, which quickly round themselves off and
contract, and become enveloped by a cell-membrane only after complete
separation" (p. 13); that in the _Equisetaceæ_ "the young spores, when
first separated, are still naked, but they soon become surrounded by a
cell-membrane" (p. 14); and that in higher plants, as in the pollen of
many Dicotyledons, "the contracting daughter-cells secrete cellulose
even during their separation" (p. 14). Here, then, in whatever way we
interpret it, the fact is that there quickly arises an outer layer
different from the contained matter. But the most significant evidence
is furnished by "the masses of protoplasm that escape into water from
the injured sacs of _Vaucheria_, which often instantly become rounded
into globular bodies," and of which the "hyaline protoplasm envelopes
the whole as a skin" (p. 41) which "is denser than the inner and more
watery substance" (p. 42). As in this case the protoplasm is but a
fragment, and as it is removed from the influence of the parent-cell,
this differentiating process can scarcely be regarded as anything more
than the effect of physico-chemical actions: a conclusion which is
supported by the statement of Sachs that "not only every vacuole in a
solid protoplasmic body, but also every thread of protoplasm which
penetrates the sap-cavity, and finally the inner side of the
protoplasm-sac which encloses the sap-cavity, is also bounded by a skin"
(p. 42). If then "every portion of a protoplasmic body immediately
surrounds itself, when it becomes isolated, with such a skin," which is
shown in all cases to arise at the surface of contact with sap or water,
this primary differentiation of outer from inner must be ascribed to the
direct action of the medium. Whether the coating thus initiated is
secreted by the protoplasm, or whether, as seems more likely, it
results from transformation of it, matters not to the argument. Either
way the action of the medium causes its formation; and either way the
many varied and complex differentiations which developed cell-walls
display, must be considered as originating from those variations of this
physically-generated covering which natural selection has taken
advantage of.

The contained protoplasm of a vegetal cell, which has self-mobility and
when liberated sometimes performs amoeba-like motions for a time, may
be regarded as an imprisoned amoeba; and when we pass from it to a
free amoeba, which is one of the simplest types of first animals, or
_Protozoa_, we naturally meet with kindred phenomena. The general trait
which here concerns us, is that while its plastic or semi-fluid sarcode
goes on protruding, in irregular ways, now this and now that part of its
periphery, and again withdrawing into its interior first one and then
another of these temporary processes, perhaps with some small portion of
food attached, there is but an indistinct differentiation of outer from
inner (a fact shown by the frequent coalescence of the pseudopodia in
Rhizopods); but that when it eventually becomes quiescent, the surface
becomes differentiated from the contents: the passing into an encysted
state, doubtless in large measure due to inherited proclivity, being
furthered, and having probably been once initiated, by the action of the
medium. The connexion between constancy of relative position among the
parts of the sarcode, and the rise of a contrast between superficial and
central parts, is perhaps best shown in the minutest and simplest
_Infusoria_, the _Monadinæ_. The genus _Monas_ is described by Kent as
"plastic and unstable in form, possessing no distinct cuticular
investment; ... the food-substances incepted at all parts of the
periphery";[45] and the genus _Scytomonas_ he says "differs from _Monas_
only in its persistent shape and accompanying greater rigidity of the
peripheral or ectoplasmic layer."[46] Describing generally such low
forms, some of which are said to have neither nucleus nor vacuole, he
remarks that in types somewhat higher "the outer or peripheral border of
the protoplasmic mass, while not assuming the character of a distinct
cell-wall or so-called cuticle, presents, as compared with the inner
substance of that mass, a slightly more solid type of composition."[47]
And it is added that these forms having so slightly differentiated an
exterior, "while usually exhibiting a more or less characteristic normal
outline, can revert at will to a pseud-amoeboid and repent state."[48]
Here, then, we have several indications of the truth that the permanent
externality of a certain part of the substance, is followed by
transformation of it into a coating unlike the substance it contains.
Indefinite and structureless in the simplest of these forms, as instance
again the _Gregarina_,[49] the limiting membrane becomes, in higher
_Infusoria_, definite and often complex: showing that the selection of
favourable variations has had largely to do with its formation. In such
types as the _Foraminifera_, which, almost structureless internally
though they are, secrete calcareous shells, it is clear that the nature
of this outer layer is determined by inherited constitution. But
recognition of this consists with the belief that the action of the
medium initiated the outer layer, specialized though it now is; and that
even still, contact with the medium excites secretion of it.

A remarkable analogy remains to be named. When we study the action of
the medium in an inorganic mass, we are led to see that between the
outer changed layer and the inner unchanged mass, comes a surface where
active change is going on. Here we have to note that, alike in the
plant-cell and in the animal-cell, there is a similar relation of parts.
Immediately inside the envelope comes the primordial utricle in the
one case, and in the other case the layer of active sarcode. In either
case the living protoplasm, placed in the position of a lining to the
cuticle of the cell, is shielded from the direct action of the medium,
and yet is not beyond the reach of its influences.

       *       *       *       *       *

Limited, as thus far drawn, to a certain common trait of those minute
organisms which are mostly below the reach of unaided vision, the
foregoing conclusion appears trivial enough. But it ceases to appear
trivial on passing into a wider field, and observing the implications,
direct and indirect, as they concern plants and animals of sensible
sizes.

Popular expositions of science have so far familiarized many readers
with a certain fundamental trait of living things around, that they have
ceased to perceive how marvellous a trait it is, and, until interpreted
by the Theory of Evolution, how utterly mysterious. In past times, the
conception of an ordinary plant or animal which prevailed, not
throughout the world at large only but among the most instructed, was
that it is a single continuous entity. One of these livings things was
unhesitatingly regarded as being in all respects a unit. Parts it might
have, various in their sizes, forms, and compositions; but these were
components of a whole which had been from the beginning in its original
nature a whole. Even to naturalists fifty years ago, the assertion that
a cabbage or a cow, though in one sense a whole, is in another sense a
vast society of minute individuals, severally living in greater or less
degrees, and some of them maintaining their independent lives
unrestrained, would have seemed an absurdity. But this truth which, like
so many of the truths established by science, is contrary to that common
sense in which most people have so much confidence, has been gradually
growing clear since the days when Leeuwenhoeck and his contemporaries
began to examine through lenses the minute structures of common plants
and animals. Each improvement in the microscope, while it has widened
our knowledge of those minute forms of life described above, has
revealed further evidence of the fact that all the larger forms of life
consist of units severally allied in their fundamental traits to these
minute forms of life. Though, as formulated by Schwann and Schleiden,
the cell-doctrine has undergone qualifications of statement; yet the
qualifications have not been such as to militate against the general
proposition that organisms visible to the naked eye, are severally
compounded of invisible organisms--using that word in its most
comprehensive sense. And then, when the development of any animal is
traced, it is found that having been primarily a nucleated cell, and
having afterwards become by spontaneous fission a cluster of nucleated
cells, it goes on through successive stages to form out of such cells,
ever multiplying and modifying in various ways, the several tissues and
organs composing the adult.

On the hypothesis of evolution this universal trait has to be accepted
not as a fact that is strange but unmeaning. It has to be accepted as
evidence that all the visible forms of life have arisen by union of the
invisible forms; which, instead of flying apart when they divided,
remained together. Various intermediate stages are known. Among plants,
those of the _Volvox_ type show us the component protophytes so feebly
combined that they severally carry on their lives with no appreciable
subordination to the life of the group. And among animals, a parallel
relation between the lives of the units and the life of the group is
shown us in _Uroglena_ and _Syncrypta_. From these first stages upwards,
may be traced through successively higher types, an increasing
subordination of the units to the aggregate; though still a
subordination leaving to them conspicuous amounts of individual
activity. Joining which facts with the phenomena presented by the
cell-multiplication and aggregation of every unfolding germ, naturalists
are now accepting the conclusion that by this process of composition
from _Protozoa_, were formed all classes of the _Metazoa_[50]--(as
animals formed by this compounding are now called); and that in a
similar way from _Protophyta_, were formed all classes of what I suppose
will be called _Metaphyta_, though the word does not yet seem to have
become current.

And now what is the general meaning of these truths, taken in connexion
with the conclusion reached in the last section. It is that this
universal trait of the _Metazoa_ and _Metaphyta_, must be ascribed to
the primitive action and re-action between the organism and its medium.
The operation of those forces which produced the primary differentiation
of outer from inner in early minute masses of protoplasm, pre-determined
this universal cell-structure of all embryos, plant and animal, and the
consequent cell-composition of adult forms arising from them. How
unavoidable is this implication, will be seen on carrying further an
illustration already used--that of the shingle-covered shore, the
pebbles on which, while being in some cases selected, have been in all
cases rounded and smoothed. Suppose a bed of such shingle to be, as we
often see it, solidified, along with interfused material, into a
conglomerate. What in such case must be considered as the chief trait of
such conglomerate; or rather--what must we regard as the chief cause of
its distinctive characters? Evidently the action of the sea. Without the
breakers, no pebbles; without the pebbles, no conglomerate. Similarly
then, in the absence of that action of the medium by which was effected
the differentiation of outer from inner in those microscopic portions of
protoplasm constituting the earliest and simplest animals and plants,
there could not have existed this cardinal trait of composition which
all the higher animals and plants show us.

So that, active as has been the part played by natural selection, alike
in modifying and moulding the original units--largely as survival of
the fittest has been instrumental in furthering and controlling the
combination of these units into visible organisms, and eventually into
large ones; yet we must ascribe to the direct effect of the medium
on the first forms of life, that character of which this
everywhere-operative factor has taken advantage.

       *       *       *       *       *

Let us turn now to another and more obvious attribute of higher
organisms, for which also there is this same general cause. Let us
observe how, on a higher platform, there recurs this differentiation of
outer from inner--how this primary trait in the living units with which
life commences, re-appears as a primary trait in those aggregates of
such units which constitute visible organisms.

In its simplest and most unmistakable form, we see this in the early
changes of an unfolding ovum of primitive type. The original fertilized
single cell, having by spontaneous fission multiplied into a cluster of
such cells, there begins to show itself a contrast between periphery and
centre; and presently there is formed a sphere consisting of a
superficial layer unlike its contents. The first change, then, is the
rise of a difference between that outer part which holds direct converse
with the surrounding medium, and that inclosed part which does not. This
primary differentiation in these compound embryos of higher animals,
parallels the primary differentiation undergone by the simplest living
things.

Leaving, for the present, succeeding changes of the compound embryo, the
significance of which we shall have to consider by-and-by, let us pass
now to the adult forms of visible plants and animals. In them we find
cardinal traits which, after what we have seen above, will further
impress us with the importance of the effects wrought on the organism by
its medium.

From the thallus of a sea-weed up to the leaf of a highly developed
phænogam, we find, at all stages, a contrast between the inner and
outer parts of these flattened masses of tissue. In the higher _Algæ_
"the outermost layers consist of smaller and firmer cells, while the
inner cells are often very large, and sometimes extremely long;"[51] and
in the leaves of trees the epidermal layer, besides differing in the
sizes and shapes of its component cells from the parenchyma forming the
inner substance of the leaf, is itself differentiated by having a
continuous cuticle, and by having the outer walls of its cells unlike
the inner walls.[52] Especially significant is the structure of such
intermediate types as the Liverworts. Beyond the differentiation of the
covering cells from the contained cells, and the contrast between upper
surface and under surface, the frond of _Marchantia polymorpha_ clearly
shows us the direct effect of incident forces; and shows us, too, how it
is involved with the effect of inherited proclivities. The frond grows
from a flat disc-shaped gemma, the two sides of which are alike. Either
side may fall uppermost; and then of the developing shoot, the side
exposed to the light "is under all circumstances the upper side which
forms stomata, the dark side becomes the under side which produces
root-hairs and leafy processes."[53] So that while we have undeniable
proof that the contrasted influences of the medium on the two sides,
initiate the differentiation, we have also proof that the completion of
it is determined by the transmitted structure of the type; since it is
impossible to ascribe the development of stomata to the direct action of
air and light. On turning from foliar expansions, to stems and roots,
facts of like meaning meet us. Speaking generally of epidermal tissue
and inner tissue, Sachs remarks that "the contrast of the two is the
plainer the more the part of the plant concerned is exposed to air and
light."[54] Elsewhere, in correspondence with this, it is said that in
roots the cells of the epidermis, though distinguished by bearing hairs,
"are otherwise similar to those of the fundamental tissue" which they
clothe,[55] while the cuticular covering is relatively thin; whereas in
stems the epidermis (often further differentiated) is composed of layers
of cells which are smaller and thicker-walled: a stronger contrast of
structure corresponding to a stronger contrast of conditions. By way of
meeting the suggestion that these respective differences are wholly due
to the natural selection of favourable variations, it will suffice if I
draw attention to the unlikeness between imbedded roots and exposed
roots. While in darkness, and surrounded by moist earth, the outermost
protective coats, even of large roots, are comparatively thin; but when
the accidents of growth entail permanent exposure to light and air,
roots acquire coverings allied in character to the coverings of
branches. That the action of the medium causes these and converse
changes, cannot be doubted when we find, on the one hand, that "roots
can become directly transformed into leaf-bearing shoots," and, on the
other hand, that in some plants certain "apparent roots are only
underground shoots," and that nevertheless "they are similar to true
roots in function and in the formation of tissue, but have no root-cap,
and, when they come to the light above ground, continue to grow in the
manner of ordinary leaf-shoots."[56] If, then, in highly developed
plants inheriting pronounced structures, this differentiating influence
of the medium is so marked, it must have been all-important at the
outset while types were undetermined.

As with plants so with animals, we find good reason for inferring that
while the specialities of the tegumentary parts must be ascribed to the
natural selection of favourable variations, their most general traits
are due to the direct action of surrounding agencies. Here we come upon
the border of those changes which are ascribable to use and disuse. But
from this class of changes we may fitly exclude those in which the parts
concerned are wholly or mainly passive. A corn and a blister will
conveniently serve to illustrate the way in which certain outer actions
initiate in the superficial tissues, effects of very marked kinds, which
are related neither to the needs of the organism nor to its normal
structure. They are neither adaptive changes nor changes towards
completion of the type. After noting them we may pass to allied, but
still more instructive, changes. Continuous pressure on any portion of
the surface causes absorption, while intermittent pressure causes
growth: the one impeding circulation and the passage of plasma from the
capillaries into the tissues, and the other aiding both. There are yet
further mechanically-produced effects. That the general character of the
ribbed skin on the under surfaces of the feet and insides of the hands
is directly due to friction and intermittent pressure, we have the
proofs:--first, that the tracts most exposed to rough usage are the most
ribbed; second, that the insides of hands subject to unusual amounts of
rough usage, as those of sailors, are strongly ribbed all over; and
third, that in hands which are very little used, the parts commonly
ribbed become quite smooth. These several kinds of evidence, however,
full of meaning as they are, I give simply to prepare the way for
evidence of a much more conclusive kind.

Where a wide ulcer has eaten away the deep-seated layer out of which the
epidermis grows, or where this layer has been destroyed by an extensive
burn, the process of healing is very significant. From the subjacent
tissues, which in the normal order have no concern with outward growth,
there is produced a new skin, or rather a pro-skin; for this substituted
outward-growing layer contains no hair-follicles or other specialities
of the original one. Nevertheless, it is like the original one in so far
that it is a continually renewed protective covering. Doubtless it may
be contended that this make-shift skin results from the inherited
proclivity of the type--the tendency to complete afresh the structure
of the species when injured. We cannot, however, ignore the immediate
influence of the medium, on recalling the facts above named, or on
remembering the further fact that an inflamed surface of skin, when not
sheltered from the air, will throw out a film of coagulable lymph. But
that the direct action of the medium is a chief factor we are clearly
shown by another case. Accident or disease occasionally causes permanent
eversion, or protrusion, of mucous membrane. After a period of
irritability, great at first but decreasing as the change advances, this
membrane assumes the general character of ordinary skin. Nor is this
all: its microscopic structure changes. Where it is a mucous membrane of
the kind covered by cylinder-epithelium, the cylinders gradually
shorten, becoming finally flat, and there results a squamous epithelium:
there is a near approach in minute composition to epidermis. Here a
tendency towards completion of the type cannot be alleged; for there is,
contrariwise, divergence from the type. The effect of the medium is so
great that, in a short time, it overcomes the inherited proclivity and
produces a structure of opposite kind to the normal one.

With but little break we come here upon a significant analogy, parallel
to an analogy already described. As was pointed out, an inorganic body
that is modifiable by its medium, acquires, after a time, an outer coat
which has already undergone such change as surrounding agencies can
effect; has a contained mass which is as yet unchanged, because
unreached; and has a surface between the two where change is going on--a
region of activity. And we saw that alike in the vegetal cell and the
animal cell there exist analogous distributions: of course with the
difference that the innermost part is not inert. Now we have to note
that in those aggregates of cells constituting the _Metaphyta_ and
_Metazoa_, analogous distributions also exist. In plants they are of
course not to be looked for in leaves and other deciduous portions, but
only in portions of long duration--stems and branches. Naturally, too,
we need not expect them in plants having modes of growth which early
produce an outer practically dead part, that effectually shields the
inner actively living part of the stem from the influence of the
medium--long-lived acrogens such as tree-ferns and long-lived endogens
such as palms. But in the highest plants, exogens, which have the
actively living part of their stems within reach of environing agencies,
we find this part,--the cambium layer,--is one from which there is a
growth inwards forming wood, and a growth outwards forming bark: there
is an increasingly thick covering (where it does not scale off) of
tissue changed by the medium, and inside this a film of highest
vitality. In so far as concerns the present argument, it is the same
with the _Metazoa_, or at least all of them which have developed
organizations. The outer skin grows up from a limiting plane, or layer,
a little distance below the surface--a place of predominant vital
activity. Here perpetually arise new cells, which, as they develop, are
thrust outwards and form the epidermis: flattening and drying up as they
approach the surface, whence, having for a time served to shield the
parts below, they finally scale off and leave younger ones to take their
places. This still undifferentiated tissue forming the base of the
epidermis, and existing also as a source of renewal in internal organs,
is the essentially living substance; and facts above given imply that it
was the action of the medium on this essentially living substance,
which, during early stages in the organization of the _Metazoa_,
initiated that protective envelope which presently became an inherited
structure--a structure which, though now mainly inherited, still
continues to be modifiable by its initiator.

Fully to perceive the way in which these evidences compel us to
recognize the influence of the medium as a primordial factor, we need
but conceive them as interpreted without it. Suppose, for instance, we
say that the structure of the epidermis is wholly determined by the
natural selection of favourable variations; what must be the position
taken in presence of the fact above named, that when mucous membrane is
exposed to the air its cell-structure changes into the cell-structure of
skin? The position taken must be this:--Though mucous membrane in a
highly-evolved individual organism, thus shows the powerful effect of
the medium on its surface; yet we must not suppose that the medium had
the effect of producing such a cell-structure on the surfaces of
primitive forms, undifferentiated though they were; or, if we suppose
that such an effect was produced on them, we must not suppose that it
was inheritable. Contrariwise, we must suppose that such effect of the
medium either was not wrought at all, or that it was evanescent: though
repeated through millions upon millions of generations it left no
traces. And we must conclude that this skin-structure arose only in
consequence of spontaneous variations not physically initiated (though
like those physically initiated) which natural selection laid hold of
and increased. Does any one think this a tenable position?

       *       *       *       *       *

And now we approach the last and chief series of morphological phenomena
which must be ascribed to the direct action of environing matters and
forces. These are presented to us when we study the early stages in the
development of the embryos of the _Metazoa_ in general.

We will set out with the fact already noted in passing, that after
repeated spontaneous fissions have changed the original fertilized
germ-cell into that cluster of cells which forms a gemmule or a
primitive ovum, the first contrast which arises is between the
peripheral parts and the central parts. Where, as with lower creatures
which do not lay up large stores of nutriment with the germs of their
offspring, the inner mass is inconsiderable, the outer layer of cells,
which are presently made quite small by repeated subdivisions, forms a
membrane extending over the whole surface--the blastoderm. The next
stage of development, which ends in this covering layer becoming double,
is reached in two ways--by invagination and by delamination; but which
is the original way and which the abridged way, is not quite certain. Of
invagination, multitudinously exemplified in the lowest types, Mr.
Balfour says:--"On purely _à priori_ grounds there is in my opinion more
to be said for invagination than for any other view";[57] and, for
present purposes, it will suffice if we limit ourselves to this: making
its nature clear to the general reader by a simple illustration.

Take a small india-rubber ball--not of the inflated kind, nor of the
solid kind, but of the kind about an inch or so in diameter with a small
hole through which, under pressure, the air escapes. Suppose that
instead of consisting of india-rubber its wall consists of small cells
made polyhedral in form by mutual pressure, and united together. This
will represent the blastoderm. Now with the finger, thrust in one side
of the ball until it touches the other: so making a cup. This action
will stand for the process of invagination. Imagine that by continuance
of it, the hemispherical cup becomes very much deepened and the opening
narrowed, until the cup becomes a sac, of which the introverted wall is
everywhere in contact with the outer wall. This will represent the
two-layered "gastrula"--the simplest ancestral form of the _Metazoa_: a
form which is permanently represented in some of the lowest types; for
it needs but tentacles round the mouth of the sac, to produce a common
hydra. Here the fact which it chiefly concerns us to remark, is that of
these two layers the outer, called in embryological language the
epiblast, continues to carry on direct converse with the forces and
matters in the environment; while the inner, called the hypoblast, comes
in contact with such only of these matters as are put into the
food-cavity which it lines. We have further to note that in the embryos
of _Metazoa_ at all advanced in organization, there arises between these
two layers a third--the mesoblast. The origin of this is seen in types
where the developmental process is not obscured by the presence of a
large food-yolk. While the above-described introversion is taking place,
and before the inner surfaces of the resulting epiblast and hypoblast
have come into contact, cells, or amoeboid units equivalent to them,
are budded off from one or both of these inner surfaces, or some part of
one or other; and these form a layer which eventually lies between the
other two--a layer which, as this mode of formation implies, never has
any converse with the surrounding medium and its contents, or with the
nutritive bodies taken in from it. The striking facts to which this
description is a necessary introduction, may now be stated. From the
outer layer, or epiblast, are developed the permanent epidermis and its
out-growths, the nervous system, and the organs of sense. From the
introverted layer, or hypoblast, are developed the alimentary canal and
those parts of its appended organs, liver, pancreas, &c., which are
concerned in delivering their secretions into the alimentary canal, as
well as the linings of those ramifying tubes in the lungs which convey
air to the places where gaseous exchange is effected. And from the
mesoblast originate the bones, the muscles, the heart and blood-vessels,
and the lymphatics, together with such parts of various internal organs
as are most remotely concerned with the outer world. Minor
qualifications being admitted, there remain the broad general facts,
that out of that part of the external layer which remains permanently
external, are developed all the structures which carry on intercourse
with the medium and its contents, active and passive; out of the
introverted part of this external layer, are developed the structures
which carry on intercourse with the quasi-external substances that are
taken into the interior--solid food, water, and air; while out of the
mesoblast are developed structures which have never had, from first to
last, any intercourse with the environment. Let us contemplate these
general facts.

Who would have imagined that the nervous system is a modified portion of
the primitive epidermis? In the absence of proofs furnished by the
concurrent testimony of embryologists during the last thirty or forty
years, who would have believed that the brain arises from an infolded
tract of the outer skin, which, sinking down beneath the surface,
becomes imbedded in other tissues and eventually surrounded by a bony
case? Yet the human nervous system in common with the nervous systems of
lower animals is thus originated. In the words of Mr. Balfour, early
embryological changes imply that--

     "the functions of the central nervous system, which were originally
     taken by the whole skin, became gradually concentrated in a special
     part of the skin which was step by step removed from the surface,
     and has finally become in the higher types a well-defined organ
     imbedded in the subdermal tissues.... The embryological evidence
     shows that the ganglion-cells of the central part of the nervous
     system are originally derived from the simple undifferentiated
     epithelial cells of the surface of the body."[58]

Less startling perhaps, though still startling enough, is the fact that
the eye is evolved out of a portion of the skin; and that while the
crystalline lens and its surroundings thus originate, the "percipient
portions of the organs of special sense, especially of optic organs, are
often formed from the same part of the primitive epidermis" which forms
the central nervous system.[59] Similarly is it with the organs for
smelling and hearing. These, too, begin as sacs formed by infoldings of
the epidermis; and while their parts are developing they are joined from
within by nervous structures which were themselves epidermic in origin.
How are we to interpret these strange transformations? Observing, as we
pass, how absurd from the point of view of the special-creationist,
would appear such a filiation of structures, and such a round-about
mode of embryonic development, we have here to remark that the process
is not one to have been anticipated as a result of natural selection.
After numbers of spontaneous variations had occurred, as the hypothesis
implies, in useless ways, the variation which primarily initiated a
nervous centre might reasonably have been expected to occur in some
internal part where it would be fitly located. Its initiation in a
dangerous place and subsequent migration to a safe place, would be
incomprehensible. Not so if we bear in mind the cardinal truth above set
forth, that the structures for holding converse with the medium and its
contents, arise in that completely superficial part which is directly
affected by the medium and its contents; and if we draw the inference
that the external actions themselves initiate the structures. These once
commenced, and furthered by natural selection where favourable to life,
would form the first term of a series ending in developed sense organs
and a developed nervous system.[60]

Though it would enforce the argument, I must, for brevity's sake, pass
over the analogous evolution of that introverted layer, or hypoblast,
out of which the alimentary canal and attached organs arise. It will
suffice to emphasize the fact that having been originally external, this
layer continues in its developed form to have a quasi-externality, alike
in its digesting part and in its respiratory part; since it continues to
deal with matters alien to the organism. I must also refrain from
dwelling at length on the fact already adverted to, that the
intermediate derived layer, or mesoblast, which was at the outset
completely internal, originates those structures which ever remain
completely internal, and have no communication with the environment save
through the structures developed from the other two: an antithesis which
has great significance.

Here, instead of dwelling on these details, it will be better to draw
attention to the most general aspect of the facts. Whatever may be the
course of subsequent changes, the first change is the formation of a
superficial layer or blastoderm; and by whatever series of
transformations the adult structure is reached, it is from the
blastoderm that all the organs forming the adult originate. Why this
marvellous fact?

Meaning is given to it if we go back to the first stage in which
_Protozoa_, having by repeated fissions formed a cluster, then arranged
themselves into a hollow sphere, as do the protophytes forming a
_Volvox_. Originally alike all over its surface, the hollow sphere of
ciliated units thus formed, would, if not quite spherical, assume a
constant attitude when moving through the water; and hence one part of
the spheroid would more frequently than the rest come in contact with
nutritive matters to be taken in. A division of labour resulting from
such a variation being advantageous, and tending therefore to increase
in descendants, would end in a differentiation like that shown in the
gemmules of various low types of _Metazoa_, which, ovate in shape, are
ciliated over one part of the surface only. There would arise a form in
which the cilium-bearing units effected locomotion and aeration; while
on the others, assuming an amoeba-like character, devolved the
function of absorbing food: a primordial specialization variously
indicated by evidence.[61] Just noting that an ancestral origin of this
kind is implied by the fact that in low types of _Metazoa_ a hollow
sphere of cells is the form first assumed by the unfolding embryo, I
draw attention to the point here of chief interest; namely that the
primary differentiation of this hollow sphere is in such case determined
by a difference in the converse of its parts with the medium and its
contents; and that the subsequent invagination arises by a continuance
of this differential converse.

Even neglecting this first stage and commencing with the next, in which
a "gastrula" has been produced by the permanent introversion of one
portion of the surface of the hollow sphere, it will suffice if we
consider what must thereafter have happened. That which continued to be
the outer surface was the part which from time to time touched quiescent
masses and occasionally received the collisions consequent on its own
motions or the motions of other things. It was the part to receive the
sound-vibrations occasionally propagated through the water; the part to
be affected more strongly than any other by those variations in the
amounts of light caused by the passing of small bodies close to it; and
the part which met those diffused molecules constituting odours. That is
to say, from the beginning the surface was the part on which there fell
the various influences pervading the environment, the part by which
there was received those impressions from the environment serving for
the guidance of actions, and the part which had to bear the mechanical
re-actions consequent upon such actions. Necessarily, therefore, the
surface was the part in which were initiated the various
instrumentalities for carrying on intercourse with the environment. To
suppose otherwise is to suppose that such instrumentalities arose
internally where they could neither be operated on by surrounding
agencies nor operate on them,--where the differentiating forces did not
come into play, and the differentiated structures had nothing to do; and
it is to suppose that meanwhile the parts directly exposed to the
differentiating forces remained unchanged. Clearly, then, organization
could not but begin on the surface; and having thus begun, its
subsequent course could not but be determined by its superficial origin.
And hence these remarkable facts showing us that individual evolution is
accomplished by successive in-foldings and in-growings. Doubtless
natural selection soon came into action, as, for example, in the removal
of the rudimentary nervous centres from the surface; since an
individual in which they were a little more deeply seated would be less
likely to be incapacitated by injury of them. And so in multitudinous
other ways. But nevertheless, as we here see, natural selection could
operate only under subjection. It could do no more than take advantage
of those structural changes which the medium and its contents initiated.

See, then, how large has been the part played by this primordial factor.
Had it done no more than give to _Protozoa_ and _Protophyta_ that
cell-form which characterizes them--had it done no more than entail the
cellular composition which is so remarkable a trait of _Metazoa_ and
_Metaphyta_--had it done no more than cause the repetition in all
visible animals and plants of that primary differentiation of outer from
inner which it first wrought in animals and plants invisible to the
naked eye; it would have done much towards giving to organisms of all
kinds certain leading traits. But it has done more than this. By causing
the first differentiations of those clusters of units out of which
visible animals in general arose, it fixed the starting place for
organization, and therefore determined the course of organization; and,
doing this, gave indelible traits to embryonic transformations and to
adult structures.

       *       *       *       *       *

Though mainly carried on after the inductive method, the argument at the
close of the foregoing section has passed into the deductive. Here let
us follow for a space the deductive method pure and simple. Doubtless in
biology _à priori_ reasoning is dangerous; but there can be no danger in
considering whether its results coincide with those reached by reasoning
_à posteriori_.

Biologists in general agree that in the present state of the world, no
such thing happens as the rise of a living creature out of non-living
matter. They do not deny, however, that at a remote period in the past,
when the temperature of the Earth's surface was much higher than at
present, and other physical conditions were unlike those we know,
inorganic matter, through successive complications, gave origin to
organic matter. So many substances once supposed to belong exclusively
to living bodies, have now been formed artificially, that men of science
scarcely question the conclusion that there are conditions under which,
by yet another step of composition, quaternary compounds of lower types
pass into those of highest types. That there once took place gradual
divergence of the organic from the inorganic, is, indeed, a necessary
implication of the hypothesis of Evolution, taken as a whole; and if we
accept it as a whole, we must put to ourselves the question--What were
the early stages of progress which followed, after the most complex form
of matter had arisen out of forms of matter a degree less complex?

At first, protoplasm could have had no proclivities to one or other
arrangement of parts; unless, indeed, a purely mechanical proclivity
towards a spherical form when suspended in a liquid. At the outset it
must have been passive. In respect of its passivity, primitive organic
matter must have been like inorganic matter. No such thing as
spontaneous variation could have occurred in it; for variation implies
some habitual course of change from which it is a divergence, and is
therefore excluded where there is no habitual course of change. In the
absence of that cyclical series of metamorphoses which even the simplest
living thing now shows us, as a result of its inherited constitution,
there could be no _point d'appui_ for natural selection. How, then, did
organic evolution begin?

If a primitive mass of organic matter was like a mass of inorganic
matter in respect of its passivity, and differed only in respect of its
greater changeableness; then we must infer that its first changes
conformed to the same general law as do the changes of an inorganic
mass. The instability of the homogeneous is a universal principle. In
all cases the homogeneous tends to pass into the heterogeneous, and the
less heterogeneous into the more heterogeneous. In the primordial units
of protoplasm, then, the step with which evolution commenced must have
been the passage from a state of complete likeness throughout the mass
to a state in which there existed some unlikeness. Further, the cause of
this step in one of these portions of organic matter, as in any portion
of inorganic matter, must have been the different exposure of its parts
to incident forces. What incident forces? Those of its medium or
environment. Which were the parts thus differently exposed? Necessarily
the outside and the inside. Inevitably, then, alike in the organic
aggregate and the inorganic aggregate (supposing it to have coherence
enough to maintain constant relative positions among its parts), the
first fall from homogeneity to heterogeneity must always have been the
differentiation of the external surface from the internal contents. No
matter whether the modification was physical or chemical, one of
composition or of decomposition, it comes within the same
generalization. The direct action of the medium was the primordial
factor of organic evolution.

       *       *       *       *       *

And now, finally, let us look at the factors in their _ensemble_, and
consider the respective parts they play: observing, especially, the ways
in which, at successive stages, they severally give place one to another
in degree of importance.

Acting alone, the primordial factor must have initiated the primary
differentiation in all units of protoplasm alike. I say alike, but I
must forthwith qualify the word. For since surrounding influences,
physical and chemical, could not be absolutely the same in all places,
especially when the first rudiments of living things had spread over a
considerable area, there necessarily arose small contrasts between the
degrees and kinds of superficial differentiation effected. As soon as
these became decided, natural selection came into play; for inevitably
the unlikenesses produced among the units had effects on their lives:
there was survival of some among the modified forms rather than others.
Utterly in the dark though we are respecting the causes which set up
that process of fission everywhere occurring among the minutest forms of
life, we must infer that, when established, it furthered the spread of
those which were most favourably differentiated by the medium. Though
natural selection must have become increasingly active when once it had
got a start; yet the differentiating action of the medium never ceased
to be a co-operator in the development of these first animals and
plants. Again taking the lead as there arose the composite forms of
animals and plants, and again losing the lead with that advancing
differentiation of these higher types which gave more scope to natural
selection, it nevertheless continued, and must ever continue, to be a
cause, both direct and indirect, of modifications in structure.

Along with that remarkable process which, beginning in minute forms with
what is called conjugation, developed into sexual generation, there came
into play causes of frequent and marked fortuitous variations. The
mixtures of constitutional proclivities made more or less unlike by
unlikenesses of physical conditions, inevitably led to occasional
concurrences of forces producing deviations of structure. These were of
course mostly suppressed, but sometimes increased, by survival of the
fittest. When, along with the growing multiplication in forms of life,
conflict and competition became continually more active, fortuitous
variations of structure of no account in the converse with the medium,
became of much account in the struggle with enemies and competitors; and
natural selection of such variations became the predominant factor.
Especially throughout the plant-world its action appears to have been
immensely the most important; and throughout that large part of the
animal world characterized by relative inactivity, the survival of
individuals that had varied in favourable ways, must all along have been
the chief cause of the divergence of species and the occasional
production of higher ones.

But gradually with that increase of activity which we see on ascending
to successively higher grades of animals, and especially with that
increased complexity of life which we also see, there came more and more
into play as a factor, the inheritance of those modifications of
structure caused by modifications of function. Eventually, among
creatures of high organization, this factor became an important one; and
I think there is reason to conclude that, in the case of the highest of
creatures, civilized men, among whom the kinds of variation which affect
survival are too multitudinous to permit easy selection of any one, and
among whom survival of the fittest is greatly interfered with, it has
become the chief factor: such aid as survival of the fittest gives,
being usually limited to the preservation of those in whom the totality
of the faculties has been most favourably moulded by functional changes.

Of course this sketch of the relations among the factors must be taken
as in large measure a speculation. We are now too far removed from the
beginnings of life to obtain data for anything more than tentative
conclusions respecting its earliest stages; especially in the absence of
any clue to the mode in which multiplication, first agamogenetic and
then gamogenetic, was initiated. But it has seemed to me not amiss to
present this general conception, by way of showing how the deductive
interpretation harmonizes with the several inferences reached by
induction.

       *       *       *       *       *

In his article on Evolution in the _Encyclopædia Britannica_, Professor
Huxley writes as follows:--

     "How far 'natural selection' suffices for the production of
     species remains to be seen. Few can doubt that, if not the whole
     cause, it is a very important factor in that operation.... On the
     evidence of palæontology, the evolution of many existing forms of
     animal life from their predecessors is no longer an hypothesis, but
     an historical fact; it is only the nature of the physiological
     factors to which that evolution is due which is still open to
     discussion."

With these passages I may fitly join a remark made in the admirable
address Prof. Huxley delivered before unveiling the statue of Mr. Darwin
in the Museum at South Kensington. Deprecating the supposition that an
authoritative sanction was given by the ceremony to the current ideas
concerning organic evolution, he said that "science commits suicide when
it adopts a creed."

Along with larger motives, one motive which has joined in prompting the
foregoing articles, has been the desire to point out that already among
biologists, the beliefs concerning the origin of species have assumed
too much the character of a creed; and that while becoming settled they
have been narrowed. So far from further broadening that broader view
which Mr. Darwin reached as he grew older, his followers appear to have
retrograded towards a more restricted view than he ever expressed. Thus
there seems occasion for recognizing the warning uttered by Prof.
Huxley, as not uncalled for.

Whatever may be thought of the arguments and conclusions set forth in
this article and the preceding one, they will perhaps serve to show that
it is as yet far too soon to close the inquiry concerning the causes of
organic evolution.


NOTE.

    [_The following passages formed part of a preface to the small
    volume in which the foregoing essay re-appeared. I append them here
    as they cannot now be conveniently prefixed._]

Though the direct bearings of the arguments contained in this Essay are
biological, the argument contained in its first half has indirect
bearings upon Psychology, Ethics, and Sociology. My belief in the
profound importance of these indirect bearings, was originally a chief
prompter to set forth the argument; and it now prompts me to re-issue it
in permanent form.

Though mental phenomena of many kinds, and especially of the simpler
kinds, are explicable only as resulting from the natural selection of
favourable variations; yet there are, I believe, still more numerous
mental phenomena, including all those of any considerable complexity,
which cannot be explained otherwise than as results of the inheritance
of functionally-produced modifications. What theory of psychological
evolution is espoused, thus depends on acceptance or rejection of the
doctrine that not only in the individual, but in the successions of
individuals, use and disuse of parts produce respectively increase and
decrease of them.

Of course there are involved the conceptions we form of the genesis and
nature of our higher emotions; and, by implication, the conceptions we
form of our moral intuitions. If functionally-produced modifications are
inheritable, then the mental associations habitually produced in
individuals by experiences of the relations between actions and their
consequences, pleasurable or painful, may, in the successions of
individuals, generate innate tendencies to like or dislike such actions.
But if not, the genesis of such tendencies is, as we shall see, not
satisfactorily explicable.

That our sociological beliefs must also be profoundly affected by the
conclusions we draw on this point, is obvious. If a nation is modified
_en masse_ by transmission of the effects produced on the natures of its
members by those modes of daily activity which its institutions and
circumstances involve; then we must infer that such institutions and
circumstances mould its members far more rapidly and comprehensively
than they can do if the solo cause of adaptation to them is the more
frequent survival of individuals who happen to have varied in
favourable ways.

I will add only that, considering the width and depth of the effects
which acceptance of one or other of these hypotheses must have on our
views of Life, Mind, Morals, and Politics, the question--Which of them
is true? demands, beyond all other questions whatever, the attention of
scientific men.

       *       *       *       *       *

After the above articles were published, I received from Dr. Downes a
copy of a paper "On the Influence of Light on Protoplasm," written by
himself and Mr. T.P. Blunt, M.A., which was communicated to the Royal
Society in 1878. It was a continuation of a preceding paper which,
referring chiefly to _Bacteria_, contended that--

     "Light is inimical to, and under favourable conditions may wholly
     prevent, the development of these organisms."

This supplementary paper goes on to show that the injurious effect of
light upon protoplasm results only in presence of oxygen. Taking first a
comparatively simple type of molecule which enters into the composition
of organic matter, the authors say, after detailing experiments:--

     "It was evident, therefore, that _oxygen_ was the agent of
     destruction under the influence of sunlight."

And accounts of experiments upon minute organisms are followed by the
sentence--

     "It seemed, therefore, that in absence of an atmosphere, light
     failed entirely to produce any effect on such organisms as were
     able to appear."

They sum up the results of their experiments in the paragraph--

     "We conclude, therefore, both from analogy and from direct
     experiment, that the observed action on these organisms is not
     dependent on light _per se_, but that the presence of free oxygen
     is necessary; light and oxygen together accomplishing what neither
     can do alone: and the inference seems irresistible that the effect
     produced is a gradual oxidation of the constituent protoplasm of
     these organisms, and that, in this respect, protoplasm, although
     living, is not exempt from laws which appear to govern the
     relations of light and oxygen to forms of matter less highly
     endowed. A force which is indirectly absolutely essential to life
     as we know it, and matter in the absence of which life has not yet
     been proved to exist, here unite for its destruction."

What is the obvious implication? If oxygen in presence of light destroys
one of these minutest portions of protoplasm, what will be its effect on
a larger portion of protoplasm? It will work an effect on the surface
instead of on the whole mass. Not like the minutest mass made inert all
through, the larger mass will be made inert only on its outside; and,
indeed, the like will happen with the minutest mass if the light or the
oxygen is very small in quantity. Hence there will result an envelope of
changed matter, inclosing and protecting the unchanged protoplasm--there
will result a rudimentary cell-wall.

FOOTNOTES:

[Footnote 41: It is probable that this shortening has resulted not
directly but indirectly, from the selection of individuals which were
noted for tenacity of hold; for the bull-dog's peculiarity in this
respect seems due to relative shortness of the upper jaw, giving the
underhung structure which, involving retreat of the nostrils, enables
the dog to continue breathing while holding.]

[Footnote 42: Though Mr. Darwin approved of this expression and
occasionally employed it, he did not adopt it for general use;
contending, very truly, that the expression Natural Selection is in some
cases more convenient. See _Animals and Plants under Domestication_
(first edition) Vol. i, p. 6; and _Origin of Species_ (sixth edition) p.
49.]

[Footnote 43: It is true that while not deliberately admitted by Mr.
Darwin, these effects are not denied by him. In his _Animals and Plants
under Domestication_ (vol. ii, 281), he refers to certain chapters in
the _Principles of Biology_, in which I have discussed this general
inter-action of the medium and the organism, and ascribed certain most
general traits to it. But though, by his expressions, he implies a
sympathetic attention to the argument, he does not in such way adopt the
conclusion as to assign to this factor any share in the genesis of
organic structures--much less that large share which I believe it has
had. I did not myself at that time, nor indeed until quite recently, see
how extensive and profound have been the influences on organization
which, as we shall presently see, are traceable to the early results of
this fundamental relation between organism and medium. I may add that it
is in an essay on "Transcendental Physiology," first published in 1857,
that the line of thought here followed out in its wider bearings, was
first entered upon.]

[Footnote 44: _Text-Book of Botany, &c._ by Julius Sachs. Translated by
A. W. Bennett and W. T. T. Dyer.]

[Footnote 45: _A Manual of the Infusoria_, by W. Saville Kent. Vol. i,
p. 232.]

[Footnote 46: _Ib._ Vol. i, p. 241.]

[Footnote 47: Kent, Vol. i, p. 56.]

[Footnote 48: _Ib._ Vol. i, p. 57.]

[Footnote 49: _The Elements of Comparative Anatomy_, by T. H. Huxley,
pp. 7-9.]

[Footnote 50: _A Treatise on Comparative Embryology_, by F. M. Balfour,
Vol. ii, chap. xiii.]

[Footnote 51: Sachs, p. 210.]

[Footnote 52: _Ibid._ pp. 83-4.]

[Footnote 53: _Ibid._ p. 185.]

[Footnote 54: _Ibid._ 80.]

[Footnote 55: Sachs, p. 83.]

[Footnote 56: _Ibid._ p. 147.]

[Footnote 57: _A Treatise on Comparative Embryology._ By Francis M.
Balfour, LL.D., F.R.S. Vol. ii, p. 343 (second edition).]

[Footnote 58: Balfour, l.c. Vol. ii, 400-1.]

[Footnote 59: Balfour, l.c. Vol. ii, p. 401.]

[Footnote 60: For a general delineation of the changes by which the
development is effected, see Balfour, l.c. Vol. ii, pp. 401-4.]

[Footnote 61: _See_ Balfour, Vol. i, 149 and Vol. ii, 343-4.]




A COUNTER-CRITICISM.

    [_First published in_ The Nineteenth Century_, for February,_ 1888.]


While I do not concur in sundry of the statements and conclusions
contained in the article entitled "A Great Confession," contributed by
the Duke of Argyll to the last number of this Review, yet I am obliged
to him for having raised afresh the question discussed in it. Though the
injunction "Rest and be thankful," is one for which in many spheres much
may be said--especially in the political, where undue restlessness is
proving very mischievous; yet rest and be thankful is an injunction out
of place in science. Unhappily, while politicians have not duly regarded
it, it appears to have been taken to heart too much by naturalists; in
so far, at least, as concerns the question of the origin of species.

The new biological orthodoxy behaves just as the old biological
orthodoxy did. In the days before Darwin, those who occupied themselves
with the phenomena of life, passed by with unobservant eyes the
multitudinous facts which point to an evolutionary origin for plants and
animals; and they turned deaf ears to those who insisted on the
significance of these facts. Now that they have come to believe in this
evolutionary origin, and have at the same time accepted the hypothesis
that natural selection has been the sole cause of the evolution, they
are similarly unobservant of the multitudinous facts which cannot
rationally be ascribed to that cause; and turn deaf ears to those who
would draw their attention to them. The attitude is the same; it is only
the creed which has changed.

But, as above implied, though the protest of the Duke of Argyll against
this attitude is quite justifiable, it seems to me that many of his
statements cannot be sustained. Some of these concern me personally, and
others are of impersonal concern. I propose to deal with them in the
order in which they occur.

       *       *       *       *       *

On page 144 the Duke of Argyll quotes me as omitting "for the present
any consideration of a factor which may be distinguished as primordial;"
and he represents me as implying by this "that Darwin's ultimate
conception of some primordial 'breathing of the breath of life' is a
conception which can be omitted only 'for the present.'" Even had there
been no other obvious interpretation, it would have been a somewhat rash
assumption that this was my meaning when referring to an omitted factor;
and it is surprising that this assumption should have been made after
reading the second of the two articles criticised, in which this factor
omitted from the first is dealt with: this omitted third factor being
the direct physico-chemical action of the medium on the organism. Such a
thought as that which the Duke of Argyll ascribes to me, is so
incongruous with the beliefs I have in many places expressed that the
ascription of it never occurred to me as possible.

Lower down on the same page are some other sentences having personal
implications, which I must dispose of before going into the general
question. The Duke says "it is more than doubtful whether any value
attaches to the new factor with which he [I] desires to supplement it
[natural selection]"; and he thinks it "unaccountable" that I "should
make so great a fuss about so small a matter as the effect of use and
disuse of particular organs as a separate and a newly-recognised
factor in the development of varieties." I do not suppose that the Duke
of Argyll intended to cast upon me the disagreeable imputation, that I
claim as new that which all who are even slightly acquainted with the
facts know to be anything rather than new. But his words certainly do
this. How he should have thus written in spite of the extensive
knowledge of the matter which he evidently has, and how he should have
thus written in presence of the evidence contained in the articles he
criticizes, I cannot understand. Naturalists, and multitudes besides
naturalists, know that the hypothesis which I am represented as putting
forward as new, is much older than the hypothesis of natural
selection--goes back at least as far as Dr. Erasmus Darwin. My purpose
was to bring into the foreground again a factor which has, I think, been
of late years improperly ignored; to show that Mr. Darwin recognized
this factor in an increasing degree as he grew older (by showing which I
should have thought I sufficiently excluded the supposition that I
brought it forward as new); to give further evidence that this factor is
in operation; to show there are numerous phenomena which cannot be
interpreted without it; and to argue that if proved operative in any
case, it may be inferred that it is operative on all structures having
active functions.

Strangely enough, this passage, in which I am represented as implying
novelty in a doctrine which I have merely sought to emphasize and
extend, is immediately succeeded by a passage in which the Duke of
Argyll himself represents the doctrine as being familiar and well
established:--

     "That organs thus enfeebled [i.e. by persistent disuse] are
     transmitted by inheritance to offspring in a like condition of
     functional and structural decline, is a correlated physiological
     doctrine not generally disputed. The converse case--of increased
     strength and development arising out of the habitual and healthy
     use of special organs, and of the transmission of these to
     offspring--is a case illustrated by many examples in the breeding
     of domestic animals. I do not know to what else we can attribute
     the long slender legs and bodies of greyhounds so manifestly
     adapted to speed of foot, or the delicate powers of smell in
     pointers and setters, or a dozen cases of modified structure
     effected by artificial selection."

In none of the assertions contained in this passage can I agree. Had the
inheritance of "functional and structural decline" been "not generally
disputed," half my argument would have been needless; and had the
inheritance of "increased strength and development" caused by use been
recognized, as "illustrated by many examples," the other half of my
argument would have been needless. But both are disputed; and, if not
positively denied, are held to be unproved. Greyhounds and pointers do
not yield valid evidence, because their peculiarities are more due to
artificial selection than to any other cause. It may, indeed, be doubted
whether greyhounds use their legs more than other dogs. Dogs of all
kinds are daily in the habit of running about and chasing one another at
the top of their speed--other dogs more frequently than greyhounds,
which are not much given to play. The occasions on which greyhounds
exercise their legs in chasing hares, occupy but inconsiderable spaces
in their lives, and can play but small parts in developing their legs.
And then, how about their long heads and sharp noses? Are these
developed by running? The structure of the greyhound is explicable as a
result mainly of selection of variations occasionally arising from
unknown causes; but it is inexplicable otherwise. Still more obviously
invalid is the evidence said to be furnished by pointers and setters.
How can these be said to exercise their organs of smell more than other
dogs? Do not all dogs occupy themselves in sniffing about here and there
all day long: tracing animals of their own kind and of other kinds?
Instead of admitting that the olfactory sense is more exercised in
pointers and setters than in other dogs, it might, contrariwise, be
contended that it is exercised less; seeing that during the greater
parts of their lives they are shut up in kennels where the varieties of
odours, on which to practise their noses, is but small. Clearly if
breeders of sporting dogs have from early days habitually bred from
those puppies of each litter which had the keenest noses (and it is
undeniable that the puppies of each litter are made different from one
another, as are the children in each human family, by unknown
combinations of causes), then the existence of such remarkable powers in
pointers and setters may be accounted for; while it is otherwise
unaccountable. These instances, and many others such, I should have
gladly used in support of my argument, had they been available; but
unfortunately they are not.

On the next page of the Duke of Argyll's article (page 145), occurs a
passage which I must quote at length before I can deal effectually with
its various statements. It runs as follows:--

     "But if natural selection is a mere phrase, vague enough and wide
     enough to cover any number of the physical causes concerned in
     ordinary generation, then the whole of Mr. Spencer's laborious
     argument in favour of his 'other factor' becomes an argument worse
     than superfluous. It is wholly fallacious in assuming that this
     'factor' and 'natural selection' are at all exclusive of, or even
     separate from, each other. The factor thus assumed to be new is
     simply one of the subordinate cases of heredity. But heredity is
     the central idea of natural selection. Therefore natural selection
     includes and covers all the causes which can possibly operate
     through inheritance. There is thus no difficulty whatever in
     referring it to the same one factor whose solitary dominion Mr.
     Spencer has plucked up courage to dispute. He will never succeed in
     shaking its dictatorship by such a small rebellion. His little
     contention is like some bit of Bumbledom setting up for Home
     Rule--some parochial vestry claiming independence of a universal
     empire. It pretends to set up for itself in some fragment of an
     idea. But here is not even a fragment to boast of or to stand up
     for. His new factor in organic evolution has neither independence
     nor novelty. Mr. Spencer is able to quote himself as having
     mentioned it in his _Principles of Biology_ published some twenty
     years ago; and by a careful ransacking of Darwin he shows that the
     idea was familiar to and admitted by him at least in his last
     edition of the _Origin of Species_.... Darwin was a man so much
     wiser than all his followers," &c.

Had there not been the Duke of Argyll's signature to the article, I
could scarcely have believed that this passage was written by him.
Remembering that on reading his article in the preceding number of this
Review, I was struck by the extent of knowledge, clearness of
discrimination, and power of exposition, displayed in it, I can scarcely
understand how there has come from the same pen a passage in which none
of these traits are exhibited. Even one wholly unacquainted with the
subject may see in the last two sentences of the above extract, how
strangely its propositions are strung together. While in the first of
them I am represented as bringing forward a "new factor," I am in the
second represented as saying that I mentioned it twenty years ago! In
the same breath I am described as claiming it as new and asserting it as
old! So, again, the uninstructed reader, on comparing the first words of
the extract with the last, will be surprised on seeing in a scientific
article statements so manifestly wanting in precision. If "natural
selection is a mere phrase," how can Mr. Darwin, who thought it
explained the origin of species, be regarded as wise? Surely it must be
more than a mere phrase if it is the key to so many otherwise
inexplicable facts. These examples of incongruous thoughts I give to
prepare the way; and will now go on to examine the chief propositions
which the quoted passage contains.

The Duke of Argyll says that "heredity is the central idea of natural
selection." Now it would, I think, be concluded that those who possess
the central idea of a thing have some consciousness of the thing. Yet
men have possessed the idea of heredity for any number of generations
and have been quite unconscious of natural selection. Clearly the
statement is misleading. It might just as truly be said that the
occurrence of structural variations in organisms is the central idea of
natural selection. And it might just as truly be said that the action of
external agencies in killing some individuals and fostering others is
the central idea of natural selection. No such assertions are correct.
The process has three factors--heredity, variation, and external
action--any one of which being absent, the process ceases. The
conception contains three corresponding ideas, and if any one be struck
out, the conception cannot be framed. No one of them is the central
idea, but they are co-essential ideas.

From the erroneous belief that "heredity is the central idea of natural
selection" the Duke of Argyll draws the conclusion, consequently
erroneous, that "natural selection includes and covers all the causes
which can possibly operate through inheritance." Had he considered the
cases which, in the _Principles of Biology_, I have cited to illustrate
the inheritance of functionally-produced modifications, he would have
seen that his inference is far from correct. I have instanced the
decrease of the jaw among civilized men as a change of structure which
cannot have been produced by the inheritance of spontaneous, or
fortuitous, variations. That changes of structure arising from such
variations may be maintained and increased in successive generations, it
is needful that the individuals in whom they occur shall derive from
them advantages in the struggle for existence--advantages, too,
sufficiently great to aid their survival and multiplication in
considerable degrees. But a decrease of jaw reducing its weight by even
an ounce (which would be a large variation), cannot, by either smaller
weight carried or smaller nutrition required, have appreciably
advantaged any person in the battle of life. Even supposing such
diminution of jaw to be beneficial (and in the resulting decay of teeth
it entails great evils), the benefit can hardly have been such as to
increase the relative multiplication of families in which it occurred
generation after generation. Unless it has done this, however, decreased
size of the jaw cannot have been produced by the natural selection of
favourable variations. How can it then have been produced? Only by
decreased function--by the habitual use of soft food, joined, probably,
with disuse of the teeth as tools. And now mark that this cause operates
on all members of a society which falls into civilized habits.
Generation after generation this decreased function changes its
component families simultaneously. Natural selection does not cover the
case at all--has nothing to do with it. And the like happens in
multitudinous other cases. Every species spreading into a new habitat,
coming in contact with new food, exposed to a different temperature, to
a drier or moister air, to a more irregular surface, to a new soil, &c.,
&c., has its members one and all subject to various changed actions,
which influence its muscular, vascular, respiratory, digestive,
and other systems of organs. If there is inheritance of
functionally-produced modifications, then all its members will transmit
the structural alterations wrought in them, and the species will change
as a whole without the supplanting of some stocks by others. Doubtless
in respect of certain changes natural selection will co-operate. If the
species, being a predacious one, is brought, by migration, into the
presence of prey of greater speed than before; then, while all its
members will have their limbs strengthened by extra action, those in
whom this muscular adaptation is greatest will have their multiplication
furthered; and inheritance of the functionally-increased structures will
be aided, in successive generations, by survival of the fittest. But it
cannot be so with the multitudinous minor changes entailed by the
modified life. The majority of these must be of such relative
unimportance that one of them cannot give to the individual in which it
becomes most marked, advantages which predominate over kindred
advantages gained by other individuals from other changes more
favourably wrought in them. In respect to these, the inherited effects
of use and disuse must accumulate independently of natural selection.

To make clear the relations of these two factors to one another and to
heredity, let us take a case in which the operations of all three may be
severally identified and distinguished.

Here is one of those persons, occasionally met with, who has an
additional finger on each hand, and who, we will suppose, is a
blacksmith. He is neither aided nor much hindered by these additional
fingers; but, by constant use, he has greatly developed the muscles of
his right arm. To avoid a perturbing factor, we will assume that his
wife, too, exercises her arms in an unusual degree: keeps a mangle, and
has all the custom of the neighbourhood. Such being the circumstances,
let us ask what are the established facts, and what are the beliefs and
disbeliefs of biologists.

The first fact is that this six-fingered blacksmith will be likely to
transmit his peculiarity to some of his children; and some of these,
again, to theirs. It is proved that, even in the absence of a like
peculiarity in the other parent, this strange variation of structure
(which we must ascribe to some fortuitous combination of causes) is
often inherited for more than one generation. Now the causes which
produce this persistent six-fingeredness are unquestionably causes which
"operate through inheritance." The Duke of Argyll says that "natural
selection includes and covers all the causes which can possibly operate
through inheritance." How does it cover the causes which operate here?
Natural selection never comes into play at all. There is no fostering of
this peculiarity, since it does not help in the struggle for existence;
and there is no reason to suppose it is such a hindrance in the struggle
that those who have it disappear in consequence. It simply gets
cancelled in the course of generations by the adverse influences of
other stocks.

While biologists admit, or rather assert, that the peculiarity in the
blacksmith's arm which was born with him is transmissible, they deny, or
rather do not admit, that the other peculiarities of his arm, induced by
daily labour--its large muscles and strengthened bones--are
transmissible. They say that there is no proof. The Duke of Argyll
thinks that the inheritance of organs enfeebled by disuse is "not
generally disputed;" and he thinks there is clear proof that the
converse change--increase of size consequent on use--is also inherited.
But biologists dispute both of these alleged kinds of inheritance. If
proof is wanted, it will be found in the proceedings at the last meeting
of the British Association, in a paper entitled "Are Acquired Characters
Hereditary?" by Professor Ray Lankester, and in the discussion raised by
that paper. Had this form of inheritance been, as the Duke of Argyll
says, "not generally disputed," I should not have written the first of
the two articles he criticizes.

But supposing it proved, as it may hereafter be, that such a
functionally-produced change of structure as the blacksmith's arm shows
us, is transmissible, the persistent inheritance is again of a kind with
which natural selection has nothing to do. If the greatly strengthened
arm enabled the blacksmith and his descendants, having like strengthened
arms, to carry on the battle of life in a much more successful way than
it was carried on by other men, survival of the fittest would ensure the
maintenance and increase of this trait in successive generations. But
the skill of the carpenter enables him to earn quite as much as his
stronger neighbour. By the various arts he has been taught, the plumber
gets as large a weekly wage. The small shopkeeper by his foresight in
buying and prudence in selling, the village-schoolmaster by his
knowledge, the farm-bailiff by his diligence and care, succeed in the
struggle for existence equally well. The advantage of a strong arm does
not predominate over the advantages which other men gain by their innate
or acquired powers of other kinds; and therefore natural selection
cannot operate so as to increase the trait. Before it can be increased,
it is neutralized by the unions of those who have it with those who have
other traits. To whatever extent, therefore, inheritance of this
functionally-produced modification operates, it operates independently
of natural selection.

One other point has to be noted--the relative importance of this factor.
If additional developments of muscles and bones may be transmitted--if,
as Mr. Darwin held, there are various other structural modifications
caused by use and disuse which imply inheritance of this kind--if
acquired characters are hereditary, as the Duke of Argyll believes; then
the area over which this factor of organic evolution operates is
enormous. Not every muscle only, but every nerve and nerve-centre, every
blood-vessel, every viscus, and nearly every bone, may be increased or
decreased by its influence. Excepting parts which have passive
functions, such as dermal appendages and the bones which form the skull,
the implication is that nearly every organ in the body may be modified
in successive generations by the augmented or diminished activity
required of it; and, save in the few cases where the change caused is
one which conduces to survival in a pre-eminent degree, it will be thus
modified independently of natural selection. Though this factor can
operate but little in the vegetal world, and can play but a subordinate
part in the lowest animal world; yet, seeing that all the active organs
of all animals are subject to its influence, it has an immense sphere.
The Duke of Argyll compares the claim made for this factor to "some bit
of Bumbledom setting up for Home Rule--some parochial vestry claiming
independence of a universal empire." But, far from this, the claim made
for it is to an empire, less indeed than that of natural selection, and
over a small part of which natural selection exercises concurrent power;
but of which the independent part has an area that is immense.

It seems to me, then, that the Duke of Argyll is mistaken in four of the
propositions contained in the passages I have quoted. The inheritance of
acquired characters _is_ disputed by biologists, though he thinks it is
not. It is not true that "heredity is the central idea of natural
selection." The statement that natural selection includes and covers all
the causes which can possibly operate through inheritance, is quite
erroneous. And if the inheritance of acquired characters is a factor at
all, the dominion it rules over is not insignificant but vast.

       *       *       *       *       *

Here I must break off, after dealing with a page and a half of the Duke
of Argyll's article. A state of health which has prevented me from
publishing anything since "The Factors of Organic Evolution," now nearly
two years ago, prevents me from carrying the matter further. Could I
have pursued the argument it would, I believe, have been practicable to
show that various other positions taken up by the Duke of Argyll do not
admit of effectual defence. But whether or not this is probable, the
reader must be left to judge for himself. On one further point only will
I say a word; and this chiefly because, if I pass it by, a mistaken
impression of a serious kind may be diffused. The Duke of Argyll
represents me as "giving up" the "famous phrase" "survival of the
fittest," and wishing "to abandon it." He does this because I have
pointed out that its words have connotations against which we must be on
our guard, if we would avoid certain distortions of thought. With equal
propriety he might say that an astronomer abandons the statement that
the planets move in elliptic orbits, because he warns his readers that
in the heavens there exist no such things as orbits, but that the
planets sweep on through a pathless void, in directions perpetually
changed by gravitation.

I regret that I should have had thus to dissent so entirely from various
of the statements made, and conclusions drawn, by the Duke of Argyll,
because, as I have already implied, I think he has done good service by
raising afresh the question he has dealt with. Though the advantages
which he hopes may result from the discussion are widely unlike the
advantages which I hope may result from it, yet we agree in the belief
that advantages may be looked for.


END OF VOL. I.

       *       *       *       *       *


Transcriber's note


The following changes have been made to the text:

Page 21: "heterogeenity" changed to "heterogeneity".

Page 47: "multipled results" changed to "multiplied results".

Page 59: "pre-Raffaelites" changed to "pre-Raphaelites".

Page 84: "heretogeneity" changed to "heterogeneity".

Page 94: "observedcoexistences" changed to "observed coexistences".

Page 97: "Cirrhipoedia" changed to "Cirrhipedia".

Page 108: "primâ facie" changed to "prima facie".

Page 112: "à fortiori" changed to "a fortiori".

Page 124: "irreconcileable" changed to "irreconcilable".

Page 140: "some thing like double" changed to "something like double".

Page 216: "representive" changed to "representative".

Page 291: "inbibe" changed to "imbibe".

Page 306: "whic hthey and living" changed to "which they and living".

Page 359: "of the two races, not" changed to "of the two races, nor".

Page 393: "parenthethic" changed to "parenthetic".

Page 411: "hypertropic" changed to "hypertrophic".