Section 13
The Use of Spies explained simply
The Art of War by Sun Tzu
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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.
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Chapter 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.
sent Ta-hsi Wu to spy upon the enemy. He was accompanied by two other
men. All three were on horseback and wore the enemy’s uniform. When it
was dark, they dismounted a few hundred feet away from the enemy’s camp
and stealthily crept up to listen, until they succeeded in catching the
passwords used in the army. Then they got on their horses again and
boldly passed through the camp under the guise of night-watchmen; and
more than once, happening to come across a soldier who was committing
some breach of discipline, they actually stopped to give the culprit a
sound cudgeling! Thus they managed to return with the fullest possible
information about the enemy’s dispositions, and received warm
commendation from the Emperor, who in consequence of their report was
able to inflict a severe defeat on his adversary."]
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
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.
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Simple English explanation
Good information is a strategic advantage. Learn from reliable sources before committing people and resources. Acting without knowledge turns courage into gambling.
1-minute summary
The Use of Spies explains that good information is a strategic advantage. In practice, learn from reliable sources before committing people and resources. It also warns that acting without knowledge turns courage into gambling. The useful lesson is to make the wise move early, while the situation is still small enough to guide.
Key takeaways
- Good information is a strategic advantage.
- Learn from reliable sources before committing people and resources.
- Acting without knowledge turns courage into gambling.
- Use the idea in one concrete decision today.
Modern example
A founder should interview real customers before building a feature based only on internal opinions.
For kids
Ask and learn before you guess.