1. Sun Tzu 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
2. In order to carry out an attack, we must have means available.
The material for raising fire should always be kept in
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
5. In attacking with fire, one should be prepared to meet five
6. (1) When fire breaks out inside to 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
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 favorable 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
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
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
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
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
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. 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
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,
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
6. Knowledge of the enemy's dispositions can only be obtained from
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
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 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 which 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
15. Spies cannot be usefully employed without a certain intuitive
16. They cannot be properly managed without benevolence and
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
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, and
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
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 Lu 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 water, because on them depends an army's
ability to move.