him at any seasonable opportunity, and not await on in hopes of
an outbreak occurring within, for fear our opponents should
themselves burn up the surrounding vegetation, and thus render
our own attempts fruitless." The famous Li Ling once baffled the
leader of the Hsiung-nu in this way. The latter, taking
advantage of a favorable wind, tried to set fire to the Chinese
general's camp, but found that every scrap of combustible
vegetation in the neighborhood had already been burnt down. On
the other hand, Po-ts`ai, a general of the Yellow Turban rebels,
was badly defeated in 184 A.D. through his neglect of this simple
precaution. "At the head of a large army he was besieging
Ch`ang-she, which was held by Huang-fu Sung. The garrison was
very small, and a general feeling of nervousness pervaded the
ranks; so Huang-fu Sung called his officers together and said:
"In war, there are various indirect methods of attack, and
numbers do not count for everything. [The commentator here
quotes Sun Tzu, V. SS. 5, 6 and 10.] Now the rebels have pitched
their camp in the midst of thick grass which will easily burn
when the wind blows. If we set fire to it at night, they will be
thrown into a panic, and we can make a sortie and attack them on
all sides at once, thus emulating the achievement of T`ien Tan.'
[See p. 90.] That same evening, a strong breeze sprang up; so
Huang-fu Sung instructed his soldiers to bind reeds together into
torches and mount guard on the city walls, after which he sent
out a band of daring men, who stealthily made their way through
the lines and started the fire with loud shouts and yells.
Simultaneously, a glare of light shot up from the city walls, and
Huang-fu Sung, sounding his drums, led a rapid charge, which
threw the rebels into confusion and put them to headlong flight."
[HOU HAN SHU, ch. 71.] ]
10. (5) When you start a fire, be to windward of it. Do
not attack from the leeward.
[Chang Yu, following Tu Yu, says: "When you make a fire,
the enemy will retreat away from it; if you oppose his retreat
and attack him then, he will fight desperately, which will not
conduce to your success." A rather more obvious explanation is
given by Tu Mu: "If the wind is in the east, begin burning to
the east of the enemy, and follow up the attack yourself from
that side. If you start the fire on the east side, and then
attack from the west, you will suffer in the same way as your
enemy."]
11. A wind that rises in the daytime lasts long, but a
night breeze soon falls.
[Cf. Lao Tzu's saying: "A violent wind does not last the
space of a morning." (TAO TE CHING, chap. 23.) Mei Yao-ch`en
and Wang Hsi say: "A day breeze dies down at nightfall, and a
night breeze at daybreak. This is what happens as a general
rule." The phenomenon observed may be correct enough, but how
this sense is to be obtained is not apparent.]
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.
[Tu Mu says: "We must make calculations as to the paths of
the stars, and watch for the days on which wind will rise,
before making our attack with fire." Chang Yu seems to interpret
the text differently: "We must not only know how to assail our
opponents with fire, but also be on our guard against similar
attacks from them."]
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.
[Ts`ao Kung's note is: "We can merely obstruct the enemy's
road or divide his army, but not sweep away all his accumulated
stores." Water can do useful service, but it lacks the terrible
destructive power of fire. This is the reason, Chang Yu
concludes, why the former is dismissed in a couple of sentences,
whereas the attack by fire is discussed in detail. Wu Tzu (ch.
4) speaks thus of the two elements: "If an army is encamped on
low-lying marshy ground, from which the water cannot run off, and
where the rainfall is heavy, it may be submerged by a flood. If
an army is encamped in wild marsh lands thickly overgrown with
weeds and brambles, and visited by frequent gales, it may be
exterminated by fire."]
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.
[This is one of the most perplexing passages in Sun Tzu.
Ts`ao Kung says: "Rewards for good service should not be
deferred a single day." And Tu Mu: "If you do not take
opportunity to advance and reward the deserving, your
subordinates will not carry out your commands, and disaster will
ensue." For several reasons, however, and in spite of the
formidable array of scholars on the other side, I prefer the
interpretation suggested by Mei Yao-ch`en alone, whose words I
will quote: "Those who want to make sure of succeeding in their
battles and assaults must seize the favorable moments when they
come and not shrink on occasion from heroic measures: that is to
say, they must resort to such means of attack of fire, water and
the like. What they must not do, and what will prove fatal, is
to sit still and simply hold to the advantages they have got."]
16. Hence the saying: The enlightened ruler lays his plans
well ahead; the good general cultivates his resources.
[Tu Mu quotes the following from the SAN LUEH, ch. 2: "The
warlike prince controls his soldiers by his authority, kits them
together by good faith, and by rewards makes them serviceable.
If faith decays, there will be disruption; if rewards are
deficient, commands will not be respected."]
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.
[Sun Tzu may at times appear to be over-cautious, but he
never goes so far in that direction as the remarkable passage in
the TAO TE CHING, ch. 69. "I dare not take the initiative, but
prefer to act on the defensive; I dare not advance an inch, but
prefer to retreat a foot."]
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.
[This is repeated from XI. ss. 17. Here I feel convinced
that it is an interpolation, for it is evident that ss. 20 ought
to follow immediately on ss. 18.]
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;
[The Wu State was destined to be a melancholy example of
this saying.]
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.
[1] "Unless you enter the tiger's lair, you cannot get hold of
the tiger's cubs."
-----------------------------------------------------------------
XIII. THE USE OF SPIES
1. Sun Tzu 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.
[Cf. II. ss. ss. 1, 13, 14.]
There will be commotion at home and abroad, and men will drop
down exhausted on the highways.
[Cf. TAO TE CHING, ch. 30: "Where troops have been
quartered, brambles and thorns spring up. Chang Yu has the note:
"We may be reminded of the saying: 'On serious ground, gather in
plunder.' Why then should carriage and transportation cause
exhaustion on the highways?--The answer is, that not victuals
alone, but all sorts of munitions of war have to be conveyed to
the army. Besides, the injunction to 'forage on the enemy' only
means that when an army is deeply engaged in hostile territory,
scarcity of food must be provided against. Hence, without being
solely dependent on the enemy for corn, we must forage in order
that there may be an uninterrupted flow of supplies. Then,
again, there are places like salt deserts where provisions being
unobtainable, supplies from home cannot be dispensed with."]
As many as seven hundred thousand families will be impeded in
their labor.
[Mei Yao-ch`en says: "Men will be lacking at the plough-
tail." The allusion is to the system of dividing land into nine
parts, each consisting of about 15 acres, the plot in the center
being cultivated on behalf of the State by the tenants of the
other eight. It was here also, so Tu Mu tells us, that their
cottages were built and a well sunk, to be used by all in common.
[See II. ss. 12, note.] In time of war, one of the families had
to serve in the army, while the other seven contributed to its
support. Thus, by a levy of 100,000 men (reckoning one able-
bodied soldier to each family) the husbandry of 700,000 families
would be affected.]
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 honors
and emoluments,
["For spies" is of course the meaning, though it would spoil
the effect of this curiously elaborate exordium if spies were
actually mentioned at this point.]
is the height of inhumanity.
[Sun Tzu's agreement is certainly ingenious. He begins by
adverting to the frightful misery and vast expenditure of blood
and treasure which war always brings in its train. Now, unless
you are kept informed of the enemy's condition, and are ready to
strike at the right moment, a war may drag on for years. The
only way to get this information is to employ spies, and it is
impossible to obtain trustworthy spies unless they are properly
paid for their services. But it is surely false economy to
grudge a comparatively trifling amount for this purpose, when
every day that the war lasts eats up an incalculably greater sum.
This grievous burden falls on the shoulders of the poor, and
hence Sun Tzu concludes that to neglect the use of spies is
nothing less than a crime against humanity.]
3. One who acts thus is no leader of men, no present help
to his sovereign, no master of victory.
[This idea, that the true object of war is peace, has its
root in the national temperament of the Chinese. Even so far
back as 597 B.C., these memorable words were uttered by Prince
Chuang of the Ch`u State: "The [Chinese] character for 'prowess'
is made up of [the characters for] 'to stay' and 'a spear'
(cessation of hostilities). Military prowess is seen in the
repression of cruelty, the calling in of weapons, the
preservation of the appointment of Heaven, the firm establishment
of merit, the bestowal of happiness on the people, putting
harmony between the princes, the diffusion of wealth."]
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.
[That is, knowledge of the enemy's dispositions, and what he
means to do.]
5. Now this foreknowledge cannot be elicited from spirits;
it cannot be obtained inductively from experience,
[Tu Mu's note is: "[knowledge of the enemy] cannot be
gained by reasoning from other analogous cases."]
nor by any deductive calculation.
[Li Ch`uan says: "Quantities like length, breadth,
distance and magnitude, are susceptible of exact mathematical
determination; human actions cannot be so calculated."]
6. Knowledge of the enemy's dispositions can only be
obtained from other men.
[Mei Yao-ch`en has rather an interesting note: "Knowledge
of the spirit-world is to be obtained by divination; information
in natural science may be sought by inductive reasoning; the laws
of the universe can be verified by mathematical calculation: but
the dispositions of an enemy are ascertainable through spies and
spies alone."]
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.
[Cromwell, one of the greatest and most practical of all
cavalry leaders, had officers styled 'scout masters,' whose
business it was to collect all possible information regarding the
enemy, through scouts and spies, etc., and much of his success in
war was traceable to the previous knowledge of the enemy's moves
thus gained." [1] ]
9. Having LOCAL SPIES means employing the services of the
inhabitants of a district.
[Tu Mu says: "In the enemy's country, win people over by
kind treatment, and use them as spies."]
10. Having INWARD SPIES, making use of officials of the
enemy.
[Tu Mu enumerates the following classes as likely to do good
service in this respect: "Worthy men who have been degraded from
office, criminals who have undergone punishment; also, favorite
