5. In attacking with fire, one should be prepared
to meet five possible developments:
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 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 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 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 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 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 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 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 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 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, and door-keepers and sentries of the
general
in command. Our spies must be commissioned to
ascertain these.