SUN TZU ON THE ART OF WAR

THE OLDEST MILITARY TREATISE IN THE WORLD

Translated from the Chinese

By LIONEL GILES, M.A. (1910)


   [This is the basic text of Sun Tzŭ on the Art of War. It was
   extracted from Mr. Giles’ complete work as titled above. The
   commentary itself, which, of course includes this work embedded
   within it, has been released as Project Gutenberg’s eBook #132.]


Contents

 CHAPTER I. LAYING PLANS
 CHAPTER II. WAGING WAR
 CHAPTER III. ATTACK BY STRATAGEM
 CHAPTER IV. TACTICAL DISPOSITIONS
 CHAPTER V. ENERGY
 CHAPTER VI. WEAK POINTS AND STRONG
 CHAPTER VII. MANŒUVERING
 CHAPTER VIII. VARIATION OF TACTICS
 CHAPTER IX. THE ARMY ON THE MARCH
 CHAPTER X. TERRAIN
 CHAPTER XI. THE NINE SITUATIONS
 CHAPTER XII. THE ATTACK BY FIRE
 CHAPTER XIII. THE USE OF SPIES




I. LAYING PLANS


1. Sun Tzŭ said: The art of war is of vital importance to the State.

2. It is a matter of life and death, a road either to safety or to
ruin. Hence it is a subject of inquiry which can on no account be
neglected.

3. The art of war, then, is governed by five constant factors, to be
taken into account in one’s deliberations, when seeking to determine
the conditions obtaining in the field.

4. These are: (1) The Moral Law; (2) Heaven; (3) Earth; (4) The
Commander; (5) Method and discipline.

5, 6. _The Moral Law_ causes the people to be in complete accord with
their ruler, so that they will follow him regardless of their lives,
undismayed by any danger.

7. Heaven signifies night and day, cold and heat, times and seasons.

8. Earth comprises distances, great and small; danger and security;
open ground and narrow passes; the chances of life and death.

9. The Commander stands for the virtues of wisdom, sincerity,
benevolence, courage and strictness.

10. By _Method and discipline_ are to be understood the marshalling of
the army in its proper subdivisions, the gradations of rank among the
officers, the maintenance of roads by which supplies may reach the
army, and the control of military expenditure.

11. These five heads should be familiar to every general: he who knows
them will be victorious; he who knows them not will fail.

12. Therefore, in your deliberations, when seeking to determine the
military conditions, let them be made the basis of a comparison, in
this wise:—

13. (1) Which of the two sovereigns is imbued with the Moral law?
(2) Which of the two generals has most ability?
(3) With whom lie the advantages derived from Heaven and Earth?
(4) On which side is discipline most rigorously enforced?
(5) Which army is the stronger?
(6) On which side are officers and men more highly trained?
(7) In which army is there the greater constancy both in reward and
punishment?

14. By means of these seven considerations I can forecast victory or
defeat.

15. The general that hearkens to my counsel and acts upon it, will
conquer: let such a one be retained in command! The general that
hearkens not to my counsel nor acts upon it, will suffer defeat:—let
such a one be dismissed!

16. While heeding the profit of my counsel, avail yourself also of any
helpful circumstances over and beyond the ordinary rules.

17. According as circumstances are favourable, one should modify one’s
plans.

18. All warfare is based on deception.

19. Hence, when able to attack, we must seem unable; when using our
forces, we must seem inactive; when we are near, we must make the enemy
believe we are far away; when far away, we must make him believe we are
near.

20. Hold out baits to entice the enemy. Feign disorder, and crush him.

21. If he is secure at all points, be prepared for him. If he is in
superior strength, evade him.

22. If your opponent is of choleric temper, seek to irritate him.
Pretend to be weak, that he may grow arrogant.

23. If he is taking his ease, give him no rest. If his forces are
united, separate them.

24. Attack him where he is unprepared, appear where you are not
expected.

25. These military devices, leading to victory, must not be divulged
beforehand.

26. Now the general who wins a battle makes many calculations in his
temple ere the battle is fought. The general who loses a battle makes
but few calculations beforehand. Thus do many calculations lead to
victory, and few calculations to defeat: how much more no calculation
at all! It is by attention to this point that I can foresee who is
likely to win or lose.




II. WAGING WAR


1. Sun Tzŭ said: In the operations of war, where there are in the field
a thousand swift chariots, as many heavy chariots, and a hundred
thousand mail-clad soldiers, with provisions enough to carry them a
thousand _li_, the expenditure at home and at the front, including
entertainment of guests, small items such as glue and paint, and sums
spent on chariots and armour, will reach the total of a thousand ounces
of silver per day. Such is the cost of raising an army of 100,000 men.

2. When you engage in actual fighting, if victory is long in coming,
the men’s weapons will grow dull and their ardour will be damped. If
you lay siege to a town, you will exhaust your strength.

3. Again, if the campaign is protracted, the resources of the State
will not be equal to the strain.

4. Now, when your weapons are dulled, your ardour damped, your strength
exhausted and your treasure spent, other chieftains will spring up to
take advantage of your extremity. Then no man, however wise, will be
able to avert the consequences that must ensue.

5. Thus, though we have heard of stupid haste in war, cleverness has
never been seen associated with long delays.

6. There is no instance of a country having benefited from prolonged
warfare.

7. It is only one who is thoroughly acquainted with the evils of war
that can thoroughly understand the profitable way of carrying it on.

8. The skilful soldier does not raise a second levy, neither are his
supply-waggons loaded more than twice.

9. Bring war material with you from home, but forage on the enemy. Thus
the army will have food enough for its needs.

10. Poverty of the State exchequer causes an army to be maintained by
contributions from a distance. Contributing to maintain an army at a
distance causes the people to be impoverished.

11. On the other hand, the proximity of an army causes prices to go up;
and high prices cause the people’s substance to be drained away.

12. When their substance is drained away, the peasantry will be
afflicted by heavy exactions.

13, 14. With this loss of substance and exhaustion of strength, the
homes of the people will be stripped bare, and three-tenths of their
incomes will be dissipated; while Government expenses for broken
chariots, worn-out horses, breast-plates and helmets, bows and arrows,
spears and shields, protective mantlets, draught-oxen and heavy
waggons, will amount to four-tenths of its total revenue.

15. Hence a wise general makes a point of foraging on the enemy. One
cartload of the enemy’s provisions is equivalent to twenty of one’s
own, and likewise a single picul of his provender is equivalent to
twenty from one’s own store.

16. Now in order to kill the enemy, our men must be roused to anger;
that there may be advantage from defeating the enemy, they must have
their rewards.

17. Therefore in chariot fighting, when ten or more chariots have been
taken, those should be rewarded who took the first. Our own flags
should be substituted for those of the enemy, and the chariots mingled
and used in conjunction with ours. The captured soldiers should be
kindly treated and kept.

18. This is called, using the conquered foe to augment one’s own
strength.

19. In war, then, let your great object be victory, not lengthy
campaigns.

20. Thus it may be known that the leader of armies is the arbiter of
the people’s fate, the man on whom it depends whether the nation shall
be in peace or in peril.




III. ATTACK BY STRATAGEM


1. Sun Tzŭ said: In the practical art of war, the best thing of all is
to take the enemy’s country whole and intact; to shatter and destroy it
is not so good. So, too, it is better to capture an army entire than to
destroy it, to capture a regiment, a detachment or a company entire
than to destroy them.

2. Hence to fight and conquer in all your battles is not supreme
excellence; supreme excellence consists in breaking the enemy’s
resistance without fighting.

3. Thus the highest form of generalship is to baulk the enemy’s plans;
the next best is to prevent the junction of the enemy’s forces; the
next in order is to attack the enemy’s army in the field; and the worst
policy of all is to besiege walled cities.

4. The rule is, not to besiege walled cities if it can possibly be
avoided. The preparation of mantlets, movable shelters, and various
implements of war, will take up three whole months; and the piling up
of mounds over against the walls will take three months more.

5. The general, unable to control his irritation, will launch his men
to the assault like swarming ants, with the result that one-third of
his men are slain, while the town still remains untaken. Such are the
disastrous effects of a siege.

6. Therefore the skilful leader subdues the enemy’s troops without any
fighting; he captures their cities without laying siege to them; he
overthrows their kingdom without lengthy operations in the field.

7. With his forces intact he will dispute the mastery of the Empire,
and thus, without losing a man, his triumph will be complete. This is
the method of attacking by stratagem.

8. It is the rule in war, if our forces are ten to the enemy’s one, to
surround him; if five to one, to attack him; if twice as numerous, to
divide our army into two.

9. If equally matched, we can offer battle; if slightly inferior in
numbers, we can avoid the enemy; if quite unequal in every way, we can
flee from him.

10. Hence, though an obstinate fight may be made by a small force, in
the end it must be captured by the larger force.

11. Now the general is the bulwark of the State: if the bulwark is
complete at all points; the State will be strong; if the bulwark is
defective, the State will be weak.

12. There are three ways in which a ruler can bring misfortune upon his
army:—

13. (1) By commanding the army to advance or to retreat, being ignorant
of the fact that it cannot obey. This is called hobbling the army.

14. (2) By attempting to govern an army in the same way as he
administers a kingdom, being ignorant of the conditions which obtain in
an army. This causes restlessness in the soldier’s minds.

15. (3) By employing the officers of his army without discrimination,
through ignorance of the military principle of adaptation to
circumstances. This shakes the confidence of the soldiers.

16. But when the army is restless and distrustful, trouble is sure to
come from the other feudal princes. This is simply bringing anarchy
into the army, and flinging victory away.

17. Thus we may know that there are five essentials for victory:
(1) He will win who knows when to fight and when not to fight.
(2) He will win who knows how to handle both superior and inferior
forces.
(3) He will win whose army is animated by the same spirit throughout
all its ranks.
(4) He will win who, prepared himself, waits to take the enemy
unprepared.
(5) He will win who has military capacity and is not interfered with by
the sovereign.
Victory lies in the knowledge of these five points.

18. Hence the saying: If you know the enemy and know yourself, you need
not fear the result of a hundred battles. If you know yourself but not
the enemy, for every victory gained you will also suffer a defeat. If
you know neither the enemy nor yourself, you will succumb in every
battle.




IV. TACTICAL DISPOSITIONS


1. Sun Tzŭ said: The good fighters of old first put themselves beyond
the possibility of defeat, and then waited for an opportunity of
defeating the enemy.

2. To secure ourselves against defeat lies in our own hands, but the
opportunity of defeating the enemy is provided by the enemy himself.

3. Thus the good fighter is able to secure himself against defeat, but
cannot make certain of defeating the enemy.

4. Hence the saying: One may _know_ how to conquer without being able
to _do_ it.

5. Security against defeat implies defensive tactics; ability to defeat
the enemy means taking the offensive.

6. Standing on the defensive indicates insufficient strength;
attacking, a superabundance of strength.

7. The general who is skilled in defence hides in the most secret
recesses of the earth; he who is skilled in attack flashes forth from
the topmost heights of heaven. Thus on the one hand we have ability to
protect ourselves; on the other, a victory that is complete.

8. To see victory only when it is within the ken of the common herd is
not the acme of excellence.

9. Neither is it the acme of excellence if you fight and conquer and
the whole Empire says, “Well done!”

10. To lift an autumn hair is no sign of great strength; to see sun and
moon is no sign of sharp sight; to hear the noise of thunder is no sign
of a quick ear.

11. What the ancients called a clever fighter is one who not only wins,
but excels in winning with ease.

12. Hence his victories bring him neither reputation for wisdom nor
credit for courage.

13. He wins his battles by making no mistakes. Making no mistakes is
what establishes the certainty of victory, for it means conquering an
enemy that is already defeated.

14. Hence the skilful fighter puts himself into a position which makes
defeat impossible, and does not miss the moment for defeating the
enemy.

15. Thus it is that in war the victorious strategist only seeks battle
after the victory has been won, whereas he who is destined to defeat
first fights and afterwards looks for victory.

16. The consummate leader cultivates the moral law, and strictly
adheres to method and discipline; thus it is in his power to control
success.

17. In respect of military method, we have, firstly, Measurement;
secondly, Estimation of quantity; thirdly, Calculation; fourthly,
Balancing of chances; fifthly, Victory.

18. Measurement owes its existence to Earth; Estimation of quantity to
Measurement; Calculation to Estimation of quantity; Balancing of
chances to Calculation; and Victory to Balancing of chances.

19. A victorious army opposed to a routed one, is as a pound’s weight
placed in the scale against a single grain.

20. The onrush of a conquering force is like the bursting of pent-up
waters into a chasm a thousand fathoms deep. So much for tactical
dispositions.




V. ENERGY


1. Sun Tzŭ said: The control of a large force is the same principle as
the control of a few men: it is merely a question of dividing up their
numbers.

2. Fighting with a large army under your command is nowise different
from fighting with a small one: it is merely a question of instituting
signs and signals.

3. To ensure that your whole host may withstand the brunt of the
enemy’s attack and remain unshaken—this is effected by manœuvers direct
and indirect.

4. That the impact of your army may be like a grindstone dashed against
an egg—this is effected by the science of weak points and strong.

5. In all fighting, the direct method may be used for joining battle,
but indirect methods will be needed in order to secure victory.

6. Indirect tactics, efficiently applied, are inexhaustible as Heaven
and Earth, unending as the flow of rivers and streams; like the sun and
moon, they end but to begin anew; like the four seasons, they pass away
but to return once more.

7. There are not more than five musical notes, yet the combinations of
these five give rise to more melodies than can ever be heard.

8. There are not more than five primary colours (blue, yellow, red,
white, and black), yet in combination they produce more hues than can
ever be seen.

9. There are not more than five cardinal tastes (sour, acrid, salt,
sweet, bitter), yet combinations of them yield more flavours than can
ever be tasted.

10. In battle, there are not more than two methods of attack—the direct
and the indirect; yet these two in combination give rise to an endless
series of manœuvers.

11. The direct and the indirect lead on to each other in turn. It is
like moving in a circle—you never come to an end. Who can exhaust the
possibilities of their combination?

12. The onset of troops is like the rush of a torrent which will even
roll stones along in its course.

13. The quality of decision is like the well-timed swoop of a falcon
which enables it to strike and destroy its victim.

14. Therefore the good fighter will be terrible in his onset, and
prompt in his decision.

15. Energy may be likened to the bending of a crossbow; decision, to
the releasing of the trigger.

16. Amid the turmoil and tumult of battle, there may be seeming
disorder and yet no real disorder at all; amid confusion and chaos,
your array may be without head or tail, yet it will be proof against
defeat.

17. Simulated disorder postulates perfect discipline; simulated fear
postulates courage; simulated weakness postulates strength.

18. Hiding order beneath the cloak of disorder is simply a question of
subdivision; concealing courage under a show of timidity presupposes a
fund of latent energy; masking strength with weakness is to be effected
by tactical dispositions.

19. Thus one who is skilful at keeping the enemy on the move maintains
deceitful appearances, according to which the enemy will act. He
sacrifices something, that the enemy may snatch at it.

20. By holding out baits, he keeps him on the march; then with a body
of picked men he lies in wait for him.

21. The clever combatant looks to the effect of combined energy, and
does not require too much from individuals. Hence his ability to pick
out the right men and utilise combined energy.

22. When he utilises combined energy, his fighting men become as it
were like unto rolling logs or stones. For it is the nature of a log or
stone to remain motionless on level ground, and to move when on a
slope; if four-cornered, to come to a standstill, but if round-shaped,
to go rolling down.

23. Thus the energy developed by good fighting men is as the momentum
of a round stone rolled down a mountain thousands of feet in height. So
much on the subject of energy.




VI. WEAK POINTS AND STRONG


1. Sun Tzŭ said: Whoever is first in the field and awaits the coming of
the enemy, will be fresh for the fight; whoever is second in the field
and has to hasten to battle, will arrive exhausted.

2. Therefore the clever combatant imposes his will on the enemy, but
does not allow the enemy’s will to be imposed on him.

3. By holding out advantages to him, he can cause the enemy to approach
of his own accord; or, by inflicting damage, he can make it impossible
for the enemy to draw near.

4. If the enemy is taking his ease, he can harass him; if well supplied
with food, he can starve him out; if quietly encamped, he can force him
to move.

5. Appear at points which the enemy must hasten to defend; march
swiftly to places where you are not expected.

6. An army may march great distances without distress, if it marches
through country where the enemy is not.

7. You can be sure of succeeding in your attacks if you only attack
places which are undefended.You can ensure the safety of your defence
if you only hold positions that cannot be attacked.

8. Hence that general is skilful in attack whose opponent does not know
what to defend; and he is skilful in defence whose opponent does not
know what to attack.

9. O divine art of subtlety and secrecy! Through you we learn to be
invisible, through you inaudible; and hence we can hold the enemy’s
fate in our hands.

10. You may advance and be absolutely irresistible, if you make for the
enemy’s weak points; you may retire and be safe from pursuit if your
movements are more rapid than those of the enemy.

11. If we wish to fight, the enemy can be forced to an engagement even
though he be sheltered behind a high rampart and a deep ditch. All we
need do is attack some other place that he will be obliged to relieve.

12. If we do not wish to fight, we can prevent the enemy from engaging
us even though the lines of our encampment be merely traced out on the
ground. All we need do is to throw something odd and unaccountable in
his way.

13. By discovering the enemy’s dispositions and remaining invisible
ourselves, we can keep our forces concentrated, while the enemy’s must
be divided.

14. We can form a single united body, while the enemy must split up
into fractions. Hence there will be a whole pitted against separate
parts of a whole, which means that we shall be many to the enemy’s few.

15. And if we are able thus to attack an inferior force with a superior
one, our opponents will be in dire straits.

16. The spot where we intend to fight must not be made known; for then
the enemy will have to prepare against a possible attack at several
different points; and his forces being thus distributed in many
directions, the numbers we shall have to face at any given point will
be proportionately few.

17. For should the enemy strengthen his van, he will weaken his rear;
should he strengthen his rear, he will weaken his van; should he
strengthen his left, he will weaken his right; should he strengthen his
right, he will weaken his left. If he sends reinforcements everywhere,
he will everywhere be weak.

18. Numerical weakness comes from having to prepare against possible
attacks; numerical strength, from compelling our adversary to make
these preparations against us.

19. Knowing the place and the time of the coming battle, we may
concentrate from the greatest distances in order to fight.

20. But if neither time nor place be known, then the left wing will be
impotent to succour the right, the right equally impotent to succour
the left, the van unable to relieve the rear, or the rear to support
the van. How much more so if the furthest portions of the army are
anything under a hundred _li_ apart, and even the nearest are separated
by several _li!_

21. Though according to my estimate the soldiers of Yüeh exceed our own
in number, that shall advantage them nothing in the matter of victory.
I say then that victory can be achieved.

22. Though the enemy be stronger in numbers, we may prevent him from
fighting. Scheme so as to discover his plans and the likelihood of
their success.

23. Rouse him, and learn the principle of his activity or inactivity.
Force him to reveal himself, so as to find out his vulnerable spots.

24. Carefully compare the opposing army with your own, so that you may
know where strength is superabundant and where it is deficient.

25. In making tactical dispositions, the highest pitch you can attain
is to conceal them; conceal your dispositions, and you will be safe
from the prying of the subtlest spies, from the machinations of the
wisest brains.

26. How victory may be produced for them out of the enemy’s own
tactics—that is what the multitude cannot comprehend.

27. All men can see the tactics whereby I conquer, but what none can
see is the strategy out of which victory is evolved.

28. Do not repeat the tactics which have gained you one victory, but
let your methods be regulated by the infinite variety of circumstances.

29. Military tactics are like unto water; for water in its natural
course runs away from high places and hastens downwards.

30. So in war, the way is to avoid what is strong and to strike at what
is weak.

31. Water shapes its course according to the nature of the ground over
which it flows; the soldier works out his victory in relation to the
foe whom he is facing.

32. Therefore, just as water retains no constant shape, so in warfare
there are no constant conditions.

33. He who can modify his tactics in relation to his opponent and
thereby succeed in winning, may be called a heaven-born captain.

34. The five elements (water, fire, wood, metal, earth) are not always
equally predominant; the four seasons make way for each other in turn.
There are short days and long; the moon has its periods of waning and
waxing.




VII. MANŒUVERING


1. Sun Tzŭ said: In war, the general receives his commands from the
sovereign.

2. Having collected an army and concentrated his forces, he must blend
and harmonise the different elements thereof before pitching his camp.

3. After that, comes tactical manœuvering, than which there is nothing
more difficult. The difficulty of tactical manœuvering consists in
turning the devious into the direct, and misfortune into gain.

4. Thus, to take a long and circuitous route, after enticing the enemy
out of the way, and though starting after him, to contrive to reach the
goal before him, shows knowledge of the artifice of _deviation_.

5. Manœuvering with an army is advantageous; with an undisciplined
multitude, most dangerous.

6. If you set a fully equipped army in march in order to snatch an
advantage, the chances are that you will be too late. On the other
hand, to detach a flying column for the purpose involves the sacrifice
of its baggage and stores.

7. Thus, if you order your men to roll up their buff-coats, and make
forced marches without halting day or night, covering double the usual
distance at a stretch, doing a hundred _li_ in order to wrest an
advantage, the leaders of all your three divisions will fall into the
hands of the enemy.

8. The stronger men will be in front, the jaded ones will fall behind,
and on this plan only one-tenth of your army will reach its
destination.

9. If you march fifty _li_ in order to outmanœuver the enemy, you will
lose the leader of your first division, and only half your force will
reach the goal.

10. If you march thirty _li_ with the same object, two-thirds of your
army will arrive.

11. We may take it then that an army without its baggage-train is lost;
without provisions it is lost; without bases of supply it is lost.

12. We cannot enter into alliances until we are acquainted with the
designs of our neighbours.

13. We are not fit to lead an army on the march unless we are familiar
with the face of the country—its mountains and forests, its pitfalls
and precipices, its marshes and swamps.

14. We shall be unable to turn natural advantages to account unless we
make use of local guides.

15. In war, practise dissimulation, and you will succeed. Move only if
there is a real advantage to be gained.

16. Whether to concentrate or to divide your troops, must be decided by
circumstances.

17. Let your rapidity be that of the wind, your compactness that of the
forest.

18. In raiding and plundering be like fire, in immovability like a
mountain.

19. Let your plans be dark and impenetrable as night, and when you
move, fall like a thunderbolt.

20. When you plunder a countryside, let the spoil be divided amongst
your men; when you capture new territory, cut it up into allotments for
the benefit of the soldiery.

21. Ponder and deliberate before you make a move.

22. He will conquer who has learnt the artifice of deviation. Such is
the art of manœuvering.

23. The Book of Army Management says: On the field of battle, the
spoken word does not carry far enough: hence the institution of gongs
and drums. Nor can ordinary objects be seen clearly enough: hence the
institution of banners and flags.

24. Gongs and drums, banners and flags, are means whereby the ears and
eyes of the host may be focussed on one particular point.

25. The host thus forming a single united body, is it impossible either
for the brave to advance alone, or for the cowardly to retreat alone.
This is the art of handling large masses of men.

26. In night-fighting, then, make much use of signal-fires and drums,
and in fighting by day, of flags and banners, as a means of influencing
the ears and eyes of your army.

27. A whole army may be robbed of its spirit; a commander-in-chief may
be robbed of his presence of mind.

28. Now a soldier’s spirit is keenest in the morning; by noonday it has
begun to flag; and in the evening, his mind is bent only on returning
to camp.

29. A clever general, therefore, avoids an army when its spirit is
keen, but attacks it when it is sluggish and inclined to return. This
is the art of studying moods.

30. Disciplined and calm, to await the appearance of disorder and
hubbub amongst the enemy:—this is the art of retaining self-possession.

31. To be near the goal while the enemy is still far from it, to wait
at ease while the enemy is toiling and struggling, to be well-fed while
the enemy is famished:—this is the art of husbanding one’s strength.

32. To refrain from intercepting an enemy whose banners are in perfect
order, to refrain from attacking an army drawn up in calm and confident
array:—this is the art of studying circumstances.

33. It is a military axiom not to advance uphill against the enemy, nor
to oppose him when he comes downhill.

34. Do not pursue an enemy who simulates flight; do not attack soldiers
whose temper is keen.

35. Do not swallow a bait offered by the enemy. Do not interfere with
an army that is returning home.

36. When you surround an army, leave an outlet free. Do not press a
desperate foe too hard.

37. Such is the art of warfare.




VIII. VARIATION OF TACTICS


1. Sun Tzŭ said: In war, the general receives his commands from the
sovereign, collects his army and concentrates his forces.

2. When in difficult country, do not encamp. In country where high
roads intersect, join hands with your allies. Do not linger in
dangerously isolated positions. In hemmed-in situations, you must
resort to stratagem. In a desperate position, you must fight.

3. There are roads which must not be followed, armies which must be not
attacked, towns which must not be besieged, positions which must not be
contested, commands of the sovereign which must not be obeyed.

4. The general who thoroughly understands the advantages that accompany
variation of tactics knows how to handle his troops.

5. The general who does not understand these, may be well acquainted
with the configuration of the country, yet he will not be able to turn
his knowledge to practical account.

6. So, the student of war who is unversed in the art of war of varying
his plans, even though he be acquainted with the Five Advantages, will
fail to make the best use of his men.

7. Hence in the wise leader’s plans, considerations of advantage and of
disadvantage will be blended together.

8. If our expectation of advantage be tempered in this way, we may
succeed in accomplishing the essential part of our schemes.

9. If, on the other hand, in the midst of difficulties we are always
ready to seize an advantage, we may extricate ourselves from
misfortune.

10. Reduce the hostile chiefs by inflicting damage on them; and make
trouble for them, and keep them constantly engaged; hold out specious
allurements, and make them rush to any given point.

11. The art of war teaches us to rely not on the likelihood of the
enemy’s not coming, but on our own readiness to receive him; not on the
chance of his not attacking, but rather on the fact that we have made
our position unassailable.

12. There are five dangerous faults which may affect a general:
(1) Recklessness, which leads to destruction;
(2) cowardice, which leads to capture;
(3) a hasty temper, which can be provoked by insults;
(4) a delicacy of honour which is sensitive to shame;
(5) over-solicitude for his men, which exposes him to worry and
trouble.

13. These are the five besetting sins of a general, ruinous to the
conduct of war.

14. When an army is overthrown and its leader slain, the cause will
surely be found among these five dangerous faults. Let them be a
subject of meditation.




IX. THE ARMY ON THE MARCH


1. Sun Tzŭ said: We come now to the question of encamping the army, and
observing signs of the enemy. Pass quickly over mountains, and keep in
the neighbourhood of valleys.

2. Camp in high places, facing the sun. Do not climb heights in order
to fight. So much for mountain warfare.

3. After crossing a river, you should get far away from it.

4. When an invading force crosses a river in its onward march, do not
advance to meet it in mid-stream. It will be best to let half the army
get across, and then deliver your attack.

5. If you are anxious to fight, you should not go to meet the invader
near a river which he has to cross.

6. Moor your craft higher up than the enemy, and facing the sun. Do not
move up-stream to meet the enemy. So much for river warfare.

7. In crossing salt-marshes, your sole concern should be to get over
them quickly, without any delay.

8. If forced to fight in a salt-marsh, you should have water and grass
near you, and get your back to a clump of trees. So much for operations
in salt-marshes.

9. In dry, level country, take up an easily accessible position with
rising ground to your right and on your rear, so that the danger may be
in front, and safety lie behind. So much for campaigning in flat
country.

10. These are the four useful branches of military knowledge which
enabled the Yellow Emperor to vanquish four several sovereigns.

11. All armies prefer high ground to low, and sunny places to dark.

12. If you are careful of your men, and camp on hard ground, the army
will be free from disease of every kind, and this will spell victory.

13. When you come to a hill or a bank, occupy the sunny side, with the
slope on your right rear. Thus you will at once act for the benefit of
your soldiers and utilise the natural advantages of the ground.

14. When, in consequence of heavy rains up-country, a river which you
wish to ford is swollen and flecked with foam, you must wait until it
subsides.

15. Country in which there are precipitous cliffs with torrents running
between, deep natural hollows, confined places, tangled thickets,
quagmires and crevasses, should be left with all possible speed and not
approached.

16. While we keep away from such places, we should get the enemy to
approach them; while we face them, we should let the enemy have them on
his rear.

17. If in the neighbourhood of your camp there should be any hilly
country, ponds surrounded by aquatic grass, hollow basins filled with
reeds, or woods with thick undergrowth, they must be carefully routed
out and searched; for these are places where men in ambush or insidious
spies are likely to be lurking.

18. When the enemy is close at hand and remains quiet, he is relying on
the natural strength of his position.

19. When he keeps aloof and tries to provoke a battle, he is anxious
for the other side to advance.

20. If his place of encampment is easy of access, he is tendering a
bait.

21. Movement amongst the trees of a forest shows that the enemy is
advancing. The appearance of a number of screens in the midst of thick
grass means that the enemy wants to make us suspicious.

22. The rising of birds in their flight is the sign of an ambuscade.
Startled beasts indicate that a sudden attack is coming.

23. When there is dust rising in a high column, it is the sign of
chariots advancing; when the dust is low, but spread over a wide area,
it betokens the approach of infantry. When it branches out in different
directions, it shows that parties have been sent to collect firewood. A
few clouds of dust moving to and fro signify that the army is
encamping.

24. Humble words and increased preparations are signs that the enemy is
about to advance. Violent language and driving forward as if to the
attack are signs that he will retreat.

25. When the light chariots come out first and take up a position on
the wings, it is a sign that the enemy is forming for battle.

26. Peace proposals unaccompanied by a sworn covenant indicate a plot.

27. When there is much running about and the soldiers fall into rank,
it means that the critical moment has come.

28. When some are seen advancing and some retreating, it is a lure.

29. When the soldiers stand leaning on their spears, they are faint
from want of food.

30. If those who are sent to draw water begin by drinking themselves,
the army is suffering from thirst.

31. If the enemy sees an advantage to be gained and makes no effort to
secure it, the soldiers are exhausted.

32. If birds gather on any spot, it is unoccupied. Clamour by night
betokens nervousness.

33. If there is disturbance in the camp, the general’s authority is
weak. If the banners and flags are shifted about, sedition is afoot. If
the officers are angry, it means that the men are weary.

34. When an army feeds its horses with grain and kills its cattle for
food, and when the men do not hang their cooking-pots over the
camp-fires, showing that they will not return to their tents, you may
know that they are determined to fight to the death.

35. The sight of men whispering together in small knots or speaking in
subdued tones points to disaffection amongst the rank and file.

36. Too frequent rewards signify that the enemy is at the end of his
resources; too many punishments betray a condition of dire distress.

37. To begin by bluster, but afterwards to take fright at the enemy’s
numbers, shows a supreme lack of intelligence.

38. When envoys are sent with compliments in their mouths, it is a sign
that the enemy wishes for a truce.

39. If the enemy’s troops march up angrily and remain facing ours for a
long time without either joining battle or taking themselves off again,
the situation is one that demands great vigilance and circumspection.

40. If our troops are no more in number than the enemy, that is amply
sufficient; it only means that no direct attack can be made. What we
can do is simply to concentrate all our available strength, keep a
close watch on the enemy, and obtain reinforcements.

41. He who exercises no forethought but makes light of his opponents is
sure to be captured by them.

42. If soldiers are punished before they have grown attached to you,
they will not prove submissive; and, unless submissive, then will be
practically useless. If, when the soldiers have become attached to you,
punishments are not enforced, they will still be useless.

43. Therefore soldiers must be treated in the first instance with
humanity, but kept under control by means of iron discipline. This is a
certain road to victory.

44. If in training soldiers commands are habitually enforced, the army
will be well-disciplined; if not, its discipline will be bad.

45. If a general shows confidence in his men but always insists on his
orders being obeyed, the gain will be mutual.




X. TERRAIN


1. Sun Tzŭ said: We may distinguish six kinds of terrain, to wit: (1)
Accessible ground; (2) entangling ground; (3) temporising ground; (4)
narrow passes; (5) precipitous heights; (6) positions at a great
distance from the enemy.

2. Ground which can be freely traversed by both sides is called
_accessible_.

3. With regard to ground of this nature, be before the enemy in
occupying the raised and sunny spots, and carefully guard your line of
supplies. Then you will be able to fight with advantage.

4. Ground which can be abandoned but is hard to re-occupy is called
_entangling_.

5. From a position of this sort, if the enemy is unprepared, you may
sally forth and defeat him. But if the enemy is prepared for your
coming, and you fail to defeat him, then, return being impossible,
disaster will ensue.

6. When the position is such that neither side will gain by making the
first move, it is called temporising ground.

7. In a position of this sort, even though the enemy should offer us an
attractive bait, it will be advisable not to stir forth, but rather to
retreat, thus enticing the enemy in his turn; then, when part of his
army has come out, we may deliver our attack with advantage.

8. With regard to _narrow passes_, if you can occupy them first, let
them be strongly garrisoned and await the advent of the enemy.

9. Should the enemy forestall you in occupying a pass, do not go after
him if the pass is fully garrisoned, but only if it is weakly
garrisoned.

10. With regard to _precipitous heights_, if you are beforehand with
your adversary, you should occupy the raised and sunny spots, and there
wait for him to come up.

11. If the enemy has occupied them before you, do not follow him, but
retreat and try to entice him away.

12. If you are situated at a great distance from the enemy, and the
strength of the two armies is equal, it is not easy to provoke a
battle, and fighting will be to your disadvantage.

13. These six are the principles connected with Earth. The general who
has attained a responsible post must be careful to study them.

14. Now an army is exposed to six several calamities, not arising from
natural causes, but from faults for which the general is responsible.
These are: (1) Flight; (2) insubordination; (3) collapse; (4) ruin; (5)
disorganisation; (6) rout.

15. Other conditions being equal, if one force is hurled against
another ten times its size, the result will be the _flight_ of the
former.

16. When the common soldiers are too strong and their officers too
weak, the result is _insubordination_. When the officers are too strong
and the common soldiers too weak, the result is _collapse_.

17. When the higher officers are angry and insubordinate, and on
meeting the enemy give battle on their own account from a feeling of
resentment, before the commander-in-chief can tell whether or no he is
in a position to fight, the result is _ruin_.

18. When the general is weak and without authority; when his orders are
not clear and distinct; when there are no fixed duties assigned to
officers and men, and the ranks are formed in a slovenly haphazard
manner, the result is utter _disorganisation_.

19. When a general, unable to estimate the enemy’s strength, allows an
inferior force to engage a larger one, or hurls a weak detachment
against a powerful one, and neglects to place picked soldiers in the
front rank, the result must be a _rout_.

20. These are six ways of courting defeat, which must be carefully
noted by the general who has attained a responsible post.

21. The natural formation of the country is the soldier’s best ally;
but a power of estimating the adversary, of controlling the forces of
victory, and of shrewdly calculating difficulties, dangers and
distances, constitutes the test of a great general.

22. He who knows these things, and in fighting puts his knowledge into
practice, will win his battles. He who knows them not, nor practises
them, will surely be defeated.

23. If fighting is sure to result in victory, then you must fight, even
though the ruler forbid it; if fighting will not result in victory,
then you must not fight even at the ruler’s bidding.

24. The general who advances without coveting fame and retreats without
fearing disgrace, whose only thought is to protect his country and do
good service for his sovereign, is the jewel of the kingdom.

25. Regard your soldiers as your children, and they will follow you
into the deepest valleys; look on them as your own beloved sons, and
they will stand by you even unto death.

26. If, however, you are indulgent, but unable to make your authority
felt; kind-hearted, but unable to enforce your commands; and incapable,
moreover, of quelling disorder: then your soldiers must be likened to
spoilt children; they are useless for any practical purpose.

27. If we know that our own men are in a condition to attack, but are
unaware that the enemy is not open to attack, we have gone only halfway
towards victory.

28. If we know that the enemy is open to attack, but are unaware that
our own men are not in a condition to attack, we have gone only halfway
towards victory.

29. If we know that the enemy is open to attack, and also know that our
men are in a condition to attack, but are unaware that the nature of
the ground makes fighting impracticable, we have still gone only
halfway towards victory.

30. Hence the experienced soldier, once in motion, is never bewildered;
once he has broken camp, he is never at a loss.

31. Hence the saying: If you know the enemy and know yourself, your
victory will not stand in doubt; if you know Heaven and know Earth, you
may make your victory complete.




XI. THE NINE SITUATIONS


1. Sun Tzŭ said: The art of war recognises nine varieties of ground:
(1) Dispersive ground; (2) facile ground; (3) contentious ground; (4)
open ground; (5) ground of intersecting highways; (6) serious ground;
(7) difficult ground; (8) hemmed-in ground; (9) desperate ground.

2. When a chieftain is fighting in his own territory, it is dispersive
ground.

3. When he has penetrated into hostile territory, but to no great
distance, it is facile ground.

4. Ground the possession of which imports great advantage to either
side, is contentious ground.

5. Ground on which each side has liberty of movement is open ground.

6. Ground which forms the key to three contiguous states, so that he
who occupies it first has most of the Empire at his command, is ground
of intersecting highways.

7. When an army has penetrated into the heart of a hostile country,
leaving a number of fortified cities in its rear, it is serious ground.

8. Mountain forests, rugged steeps, marshes and fens—all country that
is hard to traverse: this is difficult ground.

9. Ground which is reached through narrow gorges, and from which we can
only retire by tortuous paths, so that a small number of the enemy
would suffice to crush a large body of our men: this is hemmed in
ground.

10. Ground on which we can only be saved from destruction by fighting
without delay, is desperate ground.

11. On dispersive ground, therefore, fight not. On facile ground, halt
not. On contentious ground, attack not.

12. On open ground, do not try to block the enemy’s way. On ground of
intersecting highways, join hands with your allies.

13. On serious ground, gather in plunder. In difficult ground, keep
steadily on the march.

14. On hemmed-in ground, resort to stratagem. On desperate ground,
fight.

15. Those who were called skilful leaders of old knew how to drive a
wedge between the enemy’s front and rear; to prevent co-operation
between his large and small divisions; to hinder the good troops from
rescuing the bad, the officers from rallying their men.

16. When the enemy’s men were scattered, they prevented them from
concentrating; even when their forces were united, they managed to keep
them in disorder.

17. When it was to their advantage, they made a forward move; when
otherwise, they stopped still.

18. If asked how to cope with a great host of the enemy in orderly
array and on the point of marching to the attack, I should say: “Begin
by seizing something which your opponent holds dear; then he will be
amenable to your will.”

19. Rapidity is the essence of war: take advantage of the enemy’s
unreadiness, make your way by unexpected routes, and attack unguarded
spots.

20. The following are the principles to be observed by an invading
force: The further you penetrate into a country, the greater will be
the solidarity of your troops, and thus the defenders will not prevail
against you.

21. Make forays in fertile country in order to supply your army with
food.

22. Carefully study the well-being of your men, and do not overtax
them. Concentrate your energy and hoard your strength. Keep your army
continually on the move, and devise unfathomable plans.

23. Throw your soldiers into positions whence there is no escape, and
they will prefer death to flight. If they will face death, there is
nothing they may not achieve. Officers and men alike will put forth
their uttermost strength.

24. Soldiers when in desperate straits lose the sense of fear. If there
is no place of refuge, they will stand firm. If they are in the heart
of a hostile country, they will show a stubborn front. If there is no
help for it, they will fight hard.

25. Thus, without waiting to be marshalled, the soldiers will be
constantly on the _qui vive;_ without waiting to be asked, they will do
your will; without restrictions, they will be faithful; without giving
orders, they can be trusted.

26. Prohibit the taking of omens, and do away with superstitious
doubts. Then, until death itself comes, no calamity need be feared.

27. If our soldiers are not overburdened with money, it is not because
they have a distaste for riches; if their lives are not unduly long, it
is not because they are disinclined to longevity.

28. On the day they are ordered out to battle, your soldiers may weep,
those sitting up bedewing their garments, and those lying down letting
the tears run down their cheeks. But let them once be brought to bay,
and they will display the courage of a Chu or a Kuei.

29. The skilful tactician may be likened to the _shuai-jan_. Now the
_shuai-jan_ is a snake that is found in the Ch‘ang mountains. Strike at
its head, and you will be attacked by its tail; strike at its tail, and
you will be attacked by its head; strike at its middle, and you will be
attacked by head and tail both.

30. Asked if an army can be made to imitate the _shuai-jan_, I should
answer, Yes. For the men of Wu and the men of Yüeh are enemies; yet if
they are crossing a river in the same boat and are caught by a storm,
they will come to each other’s assistance just as the left hand helps
the right.

31. Hence it is not enough to put one’s trust in the tethering of
horses, and the burying of chariot wheels in the ground.

32. The principle on which to manage an army is to set up one standard
of courage which all must reach.

33. How to make the best of both strong and weak—that is a question
involving the proper use of ground.

34. Thus the skilful general conducts his army just as though he were
leading a single man, willy-nilly, by the hand.

35. It is the business of a general to be quiet and thus ensure
secrecy; upright and just, and thus maintain order.

36. He must be able to mystify his officers and men by false reports
and appearances, and thus keep them in total ignorance.

37. By altering his arrangements and changing his plans, he keeps the
enemy without definite knowledge. By shifting his camp and taking
circuitous routes, he prevents the enemy from anticipating his purpose.

38. At the critical moment, the leader of an army acts like one who has
climbed up a height and then kicks away the ladder behind him. He
carries his men deep into hostile territory before he shows his hand.

39. He burns his boats and breaks his cooking-pots; like a shepherd
driving a flock of sheep, he drives his men this way and that, and none
knows whither he is going.

40. To muster his host and bring it into danger:—this may be termed the
business of the general.

41. The different measures suited to the nine varieties of ground; the
expediency of aggressive or defensive tactics; and the fundamental laws
of human nature: these are things that must most certainly be studied.

42. When invading hostile territory, the general principle is, that
penetrating deeply brings cohesion; penetrating but a short way means
dispersion.

43. When you leave your own country behind, and take your army across
neighbourhood territory, you find yourself on critical ground. When
there are means of communication on all four sides, the ground is one
of intersecting highways.

44. When you penetrate deeply into a country, it is serious ground.
When you penetrate but a little way, it is facile ground.

45. When you have the enemy’s strongholds on your rear, and narrow
passes in front, it is hemmed-in ground. When there is no place of
refuge at all, it is desperate ground.

46. Therefore, on dispersive ground, I would inspire my men with unity
of purpose. On facile ground, I would see that there is close
connection between all parts of my army.

47. On contentious ground, I would hurry up my rear.

48. On open ground, I would keep a vigilant eye on my defences. On
ground of intersecting highways, I would consolidate my alliances.

49. On serious ground, I would try to ensure a continuous stream of
supplies. On difficult ground, I would keep pushing on along the road.

50. On hemmed-in ground, I would block any way of retreat. On desperate
ground, I would proclaim to my soldiers the hopelessness of saving
their lives.

51. For it is the soldier’s disposition to offer an obstinate
resistance when surrounded, to fight hard when he cannot help himself,
and to obey promptly when he has fallen into danger.

52. We cannot enter into alliance with neighbouring princes until we
are acquainted with their designs. We are not fit to lead an army on
the march unless we are familiar with the face of the country—its
mountains and forests, its pitfalls and precipices, its marshes and
swamps. We shall be unable to turn natural advantages to account unless
we make use of local guides.

53. To be ignorant of any one of the following four or five principles
does not befit a warlike prince.

54. When a warlike prince attacks a powerful state, his generalship
shows itself in preventing the concentration of the enemy’s forces. He
overawes his opponents, and their allies are prevented from joining
against him.

55. Hence he does not strive to ally himself with all and sundry, nor
does he foster the power of other states. He carries out his own secret
designs, keeping his antagonists in awe. Thus he is able to capture
their cities and overthrow their kingdoms.

56. Bestow rewards without regard to rule, issue orders without regard
to previous arrangements; and you will be able to handle a whole army
as though you had to do with but a single man.

57. Confront your soldiers with the deed itself; never let them know
your design. When the outlook is bright, bring it before their eyes;
but tell them nothing when the situation is gloomy.

58. Place your army in deadly peril, and it will survive; plunge it
into desperate straits, and it will come off in safety.

59. For it is precisely when a force has fallen into harm’s way that is
capable of striking a blow for victory.

60. Success in warfare is gained by carefully accommodating ourselves
to the enemy’s purpose.

61. By persistently hanging on the enemy’s flank, we shall succeed in
the long run in killing the commander-in-chief.

62. This is called ability to accomplish a thing by sheer cunning.

63. On the day that you take up your command, block the frontier
passes, destroy the official tallies, and stop the passage of all
emissaries.

64. Be stern in the council-chamber, so that you may control the
situation.

65. If the enemy leaves a door open, you must rush in.

66. Forestall your opponent by seizing what he holds dear, and subtly
contrive to time his arrival on the ground.

67. Walk in the path defined by rule, and accommodate yourself to the
enemy until you can fight a decisive battle.

68. At first, then, exhibit the coyness of a maiden, until the enemy
gives you an opening; afterwards emulate the rapidity of a running
hare, and it will be too late for the enemy to oppose you.




XII. THE ATTACK BY FIRE


1. Sun Tzŭ said: There are five ways of attacking with fire. The first
is to burn soldiers in their camp; the second is to burn stores; the
third is to burn baggage-trains; the fourth is to burn arsenals and
magazines; the fifth is to hurl dropping fire amongst the enemy.

2. In order to carry out an attack, we must have means available. The
material for raising fire should always be kept in readiness.

3. There is a proper season for making attacks with fire, and special
days for starting a conflagration.

4. The proper season is when the weather is very dry; the special days
are those when the moon is in the constellations of the Sieve, the
Wall, the Wing or the Cross-bar; for these four are all days of rising
wind.

5. In attacking with fire, one should be prepared to meet five possible
developments:

6. (1) When fire breaks out inside the enemy’s camp, respond at once
with an attack from without.

7. (2) If there is an outbreak of fire, but the enemy’s soldiers remain
quiet, bide your time and do not attack.

8. (3) When the force of the flames has reached its height, follow it
up with an attack, if that is practicable; if not, stay where you are.

9. (4) If it is possible to make an assault with fire from without, do
not wait for it to break out within, but deliver your attack at a
favourable moment.

10. (5) When you start a fire, be to windward of it. Do not attack from
the leeward.

11. A wind that rises in the daytime lasts long, but a night breeze
soon falls.

12. In every army, the five developments connected with fire must be
known, the movements of the stars calculated, and a watch kept for the
proper days.

13. Hence those who use fire as an aid to the attack show intelligence;
those who use water as an aid to the attack gain an accession of
strength.

14. By means of water, an enemy may be intercepted, but not robbed of
all his belongings.

15. Unhappy is the fate of one who tries to win his battles and succeed
in his attacks without cultivating the spirit of enterprise; for the
result is waste of time and general stagnation.

16. Hence the saying: The enlightened ruler lays his plans well ahead;
the good general cultivates his resources.

17. Move not unless you see an advantage; use not your troops unless
there is something to be gained; fight not unless the position is
critical.

18. No ruler should put troops into the field merely to gratify his own
spleen; no general should fight a battle simply out of pique.

19. If it is to your advantage, make a forward move; if not, stay where
you are.

20. Anger may in time change to gladness; vexation may be succeeded by
content.

21. But a kingdom that has once been destroyed can never come again
into being; nor can the dead ever be brought back to life.

22. Hence the enlightened ruler is heedful, and the good general full
of caution. This is the way to keep a country at peace and an army
intact.




XIII. THE USE OF SPIES


1. Sun Tzŭ said: Raising a host of a hundred thousand men and marching
them great distances entails heavy loss on the people and a drain on
the resources of the State. The daily expenditure will amount to a
thousand ounces of silver. There will be commotion at home and abroad,
and men will drop down exhausted on the highways. As many as seven
hundred thousand families will be impeded in their labor.

2. Hostile armies may face each other for years, striving for the
victory which is decided in a single day. This being so, to remain in
ignorance of the enemy’s condition simply because one grudges the
outlay of a hundred ounces of silver in honours and emoluments, is the
height of inhumanity.

3. One who acts thus is no leader of men, no present help to his
sovereign, no master of victory.

4. Thus, what enables the wise sovereign and the good general to strike
and conquer, and achieve things beyond the reach of ordinary men, is
_foreknowledge_.

5. Now this foreknowledge cannot be elicited from spirits; it cannot be
obtained inductively from experience, nor by any deductive calculation.

6. Knowledge of the enemy’s dispositions can only be obtained from
other men.

7. Hence the use of spies, of whom there are five classes: (1) Local
spies; (2) inward spies; (3) converted spies; (4) doomed spies; (5)
surviving spies.

8. When these five kinds of spy are all at work, none can discover the
secret system. This is called “divine manipulation of the threads.” It
is the sovereign’s most precious faculty.

9. Having _local spies_ means employing the services of the inhabitants
of a district.

10. Having _inward spies_, making use of officials of the enemy.

11. Having _converted spies_, getting hold of the enemy’s spies and
using them for our own purposes.

12. Having _doomed spies_, doing certain things openly for purposes of
deception, and allowing our own spies to know of them and report them
to the enemy.

13. _Surviving spies_, finally, are those who bring back news from the
enemy’s camp.

14. Hence it is that with none in the whole army are more intimate
relations to be maintained than with spies. None should be more
liberally rewarded. In no other business should greater secrecy be
preserved.

15. Spies cannot be usefully employed without a certain intuitive
sagacity.

16. They cannot be properly managed without benevolence and
straightforwardness.

17. Without subtle ingenuity of mind, one cannot make certain of the
truth of their reports.

18. Be subtle! be subtle! and use your spies for every kind of
business.

19. If a secret piece of news is divulged by a spy before the time is
ripe, he must be put to death together with the man to whom the secret
was told.

20. Whether the object be to crush an army, to storm a city, or to
assassinate an individual, it is always necessary to begin by finding
out the names of the attendants, the aides-de-camp, the door-keepers
and sentries of the general in command. Our spies must be commissioned
to ascertain these.

21. The enemy’s spies who have come to spy on us must be sought out,
tempted with bribes, led away and comfortably housed. Thus they will
become converted spies and available for our service.

22. It is through the information brought by the converted spy that we
are able to acquire and employ local and inward spies.

23. It is owing to his information, again, that we can cause the doomed
spy to carry false tidings to the enemy.

24. Lastly, it is by his information that the surviving spy can be used
on appointed occasions.

25. The end and aim of spying in all its five varieties is knowledge of
the enemy; and this knowledge can only be derived, in the first
instance, from the converted spy. Hence it is essential that the
converted spy be treated with the utmost liberality.

26. Of old, the rise of the Yin dynasty was due to I Chih who had
served under the Hsia. Likewise, the rise of the Chou dynasty was due
to Lü Ya who had served under the Yin.

27. Hence it is only the enlightened ruler and the wise general who
will use the highest intelligence of the army for purposes of spying
and thereby they achieve great results. Spies are a most important
element in war, because on them depends an army’s ability to move.