The Art of War
13. Surviving spies, finally, are those who bring back news from the enemy’s camp.
This is the ordinary class of spies, properly so called, forming a regular part of the army. Tu Mu says: “Your surviving spy must be a man of keen intellect, though in outward appearance a fool; of shabby exterior, but with a will of iron. He must be active, robust, endowed with physical strength and courage; thoroughly accustomed to all sorts of dirty work, able to endure hunger and cold, and to put up with shame and ignominy.”
Ho Shih tells the following story of Ta-hsi Wu of the Sui dynasty: “When he was governor of Eastern Ch’in, Shên-wu of Ch’i made a hostile movement upon Sha-yüan. The Emperor T’ai Tsu 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 by 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 cudgelling!
“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.
Tu Mu and Mei Yao-ch’ên point out that the spy is privileged to enter even the general’s private sleeping-tent.
None should be more liberally rewarded. In no other business should greater secrecy be preserved.
Tu Mu [says that] all communications with spies should be carried on “mouth-to-ear.” . . . The following remarks on spies may be quoted from [Marshal] Turenne, who made perhaps larger use of them than any previous commander: “Spies are attached to those who give them most; he who pays them ill is never served. They should never be known to anybody; nor should they know one another. When they propose anything very material, secure their persons, or have in your possession their wives and children as hostages for their fidelity. Never communicate anything to them but what is absolutely necessary that they should know.”
15. Spies cannot be usefully employed without a certain intuitive sagacity.
Mei Yao-ch’ên says: “In order to use them, one must know fact from falsehood, and be able to discriminate between honesty and double-dealing.” . . . Tu Mu strangely refers these attributes to the spies themselves: “Before using spies we must assure ourselves as to their integrity of character and the extent of their experience and skill.” But he continues: “A brazen face and a crafty disposition are more dangerous than mountains or rivers; it takes a man of genius to penetrate such.” So that we are left in some doubt as to his real opinion on the passage.
And if, to be sure, sometimes you need to conceal a fact with words, do it in such a way that it does not become known, or, if it does become known, that you have a ready and quick defence.
Niccolò Machiavelli, “Advice to Raffaello Girolami When He Went as Ambassador to the Emperor” (1522)
16. They cannot be properly managed without benevolence and straightforwardness.
Chang Yü [interprets the Chinese as] “not grudging them honours and pay”; “showing no distrust of their honesty.” [So that the passage would read:] “When you have attracted them by substantial offers, you must treat them with absolute sincerity; then they will work for you with all their might.”
17. Without subtle ingenuity of mind, one cannot make certain of the truth of their reports.
Mei Yao-ch’ên says: “Be on your guard against the possibility of spies going over to the service of the enemy.”
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.
The Chinese here is so concise and elliptical that some expansion is necessary for the proper understanding of it. . . . Word for word [it reads]: “If spy matters are heard before [our plans] are carried out,” etc. . . . The main point of Sun Tzu’s injunction [must surely be that] whereas you kill the spy himself “as a punishment for letting out the secret,” the object of killing the other man is only, as Ch’ên Hao puts it, “to stop his mouth” and prevent the news leaking any further. If it had already been repeated to others, this object would not be gained.
Either way, Sun Tzu lays himself open to the charge of inhumanity, though Tu Mu tries to defend him by saying that the man deserves to be put to death, for the spy would certainly not have told the secret unless the other had been at pains to worm it out of him.
Men should either be treated generously or destroyed, because they take revenge for slight injuries—for heavy ones, they cannot.
Niccolò Machiavelli, The Prince (1532)
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,
those who wait on others, servants and retainers generally.
the aides-de-camp,
[Tu Yu describes them as] “those whose duty it is to keep the general supplied with information,” which naturally necessitates frequent interviews with him.
the door-keepers and sentries of the general in command. Our spies must be commissioned to ascertain these.
As the first step, no doubt, towards finding out if any of these important functionaries can be won over by bribery.
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.
Tu Yu expands this into “through conversion of the enemy’s spies we learn the enemy’s condition.” And Chang Yü says: “We must tempt the converted spy into our service, because it is he that knows which of the local inhabitants are greedy of gain, and which of the officials are open to corruption.”
23. It is owing to his information, again, that we can cause the doomed spy to carry false tidings to the enemy.
[Chang Yü puts it thus:] “Because the converted spy knows how the enemy can best be deceived.”
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.
He not only brings information himself, but makes it possible to use the other kinds of spy to advantage.
Hence it is essential that the converted spy be treated with the utmost liberality.
26. Of old, the rise of the Yin dynasty
Sun Tzu means the Shang dynasty, founded in 1766 B.C. Its name was changed to Yin by P’an Kêng in 1401.
was due to I Chih,
Better known as I Yin, the famous general and statesman who took part in Ch’êng T’ang’s campaign against Chieh Kuei.
who had served under the Hsia. Likewise, the rise of the Chou dynasty was due to Lü Ya,
[Lü Ya was also known as] Lü Shang. [He] rose to high office under the tyrant Chou Hsin, whom he afterwards helped to overthrow. . . . He is said to have composed a treatise on war.
who had served under the Yin.
There is less precision in the Chinese than I have thought it well to introduce into my translation, and the commentaries on this passage are by no means explicit. But, having regard to the context, we can hardly doubt that Sun Tzu is holding up I Chih and Lü Ya as illustrious examples of the converted spy, or somet
hing closely analogous. His suggestion is, that the Hsia and Yin dynasties were upset owing to the intimate knowledge of their weaknesses and shortcomings which these former ministers were able to impart to the other side. Mei Yao-ch’ên appears to resent any such aspersion on these historic names: “I Yin and Lü Ya,” he says, “were not rebels against the Government. Hsia could not employ the former, hence Yin employed him. Yin could not employ the latter, hence Chou employed him. Their great achievements were all for the good of the people.”
Ho Shih is also indignant: “How should two divinely inspired men such as I and Lü have acted as common spies? Sun Tzu’s mention of them simply means that the proper use of the five classes of spies is a matter which requires men of the highest mental calibre, like I and Lü, whose wisdom and capacity qualified them for the task. [His] words only emphasize this point.” Ho Shih believes then that the two heroes are mentioned on account of their supposed skill in the use of spies. But this is [a] very weak [interpretation].
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,
Ch’ên Hao . . . points out that “the god-like wisdom of Ch’êng T’ang and Wu Wang led them to employ I Yin and Lü Shang.”
and thereby they achieve great results.
Tu Mu closes with a note of warning: “Just as water, which carries a boat from bank to bank, may also be the means of sinking it, so reliance on spies, while productive of great results, is oft-times the cause of utter destruction.”
Spies are a most important element in war, because on them depends an army’s ability to move.
Chia Lin says that an army without spies is like a man without ears or eyes.
APPENDIX: THE COMMENTATORS
by Lionel Giles edited by Dallas Galvin
SUN TZU CAN BOAST an exceptionally long and distinguished roll of commentators, which would do honour to any classic. . . .
1. TS’AO TS’AO, ALSO KNOWN AS TS’AO KUNG AND LATER WEI WU TI, A.D. 155-220
There is hardly any room for doubt that the earliest commentary on Sun Tzu actually came from the pen of this extraordinary man, whose biography in the San Kuo Chih reads like a romance. One of the greatest military geniuses that the world has seen, and Napoleonic in the scale of his operations, he was especially famed for the marvellous rapidity of his marches, which has found expression in the line, “Talk of Ts’ao Ts’ao, and Ts’ao Ts’ao will appear.” Ou-yang Hsiu says of him that he was a great captain who
measured his strength against Tung Cho, Lü Pu and the two Yüan, father and son, and vanquished them all; whereupon he divided the Empire of Han with Wu and Shu, and made himself king. It is recorded that whenever a council of war was held by Wei on the eve of a far-reaching campaign, he had all his calculations ready; those generals who made use of them did not lose one battle in ten; those who ran counter to them in any particular saw their armies incontinently beaten and put to flight.
Ts’ao Kung’s notes on Sun Tzu, models of austere brevity, are so thoroughly characteristic of the stern commander known to history, that it is hard indeed to conceive of them as the work of a mere littérateur. Sometimes, indeed, owing to extreme compression, they are scarcely intelligible and stand no less in need of a commentary than the text itself. . . . Ts’ao Kung is the reputed author of a book on war in 100,000 odd words, now lost. . . .
2. MÊNG SHIH, C. A.D. 502-557? OR POSSIBLY AS EARLY AS THE THIRD CENTURY
The commentary which has come down to us under this name is comparatively meagre, and nothing about the author is known. Even his personal name has not been recorded. . . . [H]e is named [as the] last of the “Five Commentators,” the others being Wei Wu Ti [Ts’ao Ts’ao], Tu Mu, Ch’ên Hao and Chia Lin.
3. LI CH’ÜAN, EIGHTH CENTURY A.D.
[He] was a well-known writer on military tactics. [One of his treatises] has been in constant use down to the present day. [One of his works recounts the] lives of famous generals from the Chou to the T’ang Dynasties. . . . He is also generally supposed to be the real author of [a] popular Taoist tract. . . . His notes are mostly short and to the point, and he frequently illustrates his remarks by anecdotes from Chinese history. [However, his commentaries are based on a version of the Sun Tzu text that differs considerably from those now extant.]
4. TU YU, DIED 812 A.D.
[He] did not publish a separate commentary on Sun Tzu, his notes being taken from the T’ung Tien, the encyclopædic treatise on the Constitution which was his life-work. They are largely repetitions of Ts’ao Kung and Mêng Shih, besides which it is believed that he drew on the ancient commentaries of Wang Ling and others. . . . [The poet and commentator Tu Mu was his grandson.]
5. TU MU, 803-852 A.D.
[He] is perhaps best known as a poet—a bright star even in the glorious galaxy of the T’ang period. We learn from Ch’ao Kung-wu that although he had no practical experience of war, he was extremely fond of discussing the subject, and was moreover well read in the military history of the Ch’un Ch’iu and Chan Kuo eras. His notes, therefore, are well worth attention. They are very copious, and replete with historical parallels. The gist of Sun Tzu’s work is thus summarised by him: “Practise benevolence and justice, but on the other hand make full use of artifice and measures of expediency.” He further declared that all the military triumphs and disasters of the thousand years which had elapsed since Sun Wu’s death would, upon examination, be found to uphold and corroborate, in every particular, the maxims contained in his book. . . .
6. CH’ËN HAO, T’ANG DYNASTY (618-907 A.D.)
[He] appears to have been a contemporary of Tu Mu. Ch’ao Kung-wu says that he was impelled to write a new commentary on Sun Tzu because Ts’ao Kung’s on the one hand was too obscure and subtle, and that of Tu Mu on the other too long-winded and diffuse. Ou-yang Hsiu, writing in the middle of the 11th century, calls Ts’ao Kung, Tu Mu and Ch’ên Hao the three chief commentators on Sun Tzu. . . . [Ch’ên’s] commentary, though not lacking in merit, must rank below those of his predecessors.
7. CHIA LIN, NO DATES, BUT HE LIVED DURING THE T’ANG DYNASTY (618-907 A.D.)
[His commentary on Sun Tzu] is of somewhat scanty texture, and in point of quality, too, perhaps the least valuable of the eleven.
8. MEI YAO-CH’ËN, 1002-1060
[C]ommonly known by his “style” as Mei Shêng-yü,[he] was, like Tu Mu, a poet of distinction. His commentary was published with a laudatory preface by the great Ou-yang Hsiu, from which we may cull the following:
Later scholars have misread Sun Tzu, distorting his words and trying to make them square with their own one-sided views. Thus, though commentators have not been lacking, only a few have proved equal to the task. My friend Shêng-yü has not fallen into this mistake. In attempting to provide a critical commentary for Sun Tzu’s work, he does not lose sight of the fact that these sayings were intended for states engaged in internecine warfare; that the author is not concerned with the military conditions prevailing under the sovereigns of the three ancient dynasties (the Hsia, the Shang, and the Chou), nor with the nine punitive measures prescribed to the Minister of War. Again, Sun Wu loved brevity of diction, but his meaning is always deep. Whether the subject be marching an army, or handling soldiers, or estimating the enemy, or controlling the forces of victory, it is always systematically treated; the sayings are bound together in strict logical sequence, though this has been obscured by commentators who have probably failed to grasp their meaning. In his own commentary, Mei Shêng-yü has brushed aside all the obstinate prejudices of these critics, and has tried to bring out the true meaning of Sun Tzu himself. In this way, the clouds of confusion have been dispersed and the sayings made clear. I am convinced that the present work deserves to be handed down side by side with the three great commentaries; and for a great deal that they find in the sayings, coming generations will have constant reason to thank my friend Shêng-yü
Making some allowance fo
r the exuberance of friendship, I am inclined to endorse this favourable judgment, and would certainly place him above Ch’ên Hao in order of merit.
9. WANG HSI, SUNG DYNASTY (960-1279 A.D.)
[He] is decidedly original in some of his interpretations, but much less judicious than Mei Yao-ch’ên and on the whole not a very trustworthy guide. He is fond of comparing his own commentary with that of Ts’ao Kung, but the comparison is not always flattering to him. We learn from Ch’ao Kung-wu that Wang Hsi revised the ancient text of Sun Tzu, filling up lacunæ and correcting mistakes.
10. HO YEN-HSI, SUNG DYNASTY (960-1279 A.D.)
[There is some controversy over his personal name and biography.] . . . he appears simply as Ho Shih in the Yü Hai, and [it has been said] that his personal name is unknown. . . . [His] commentary . . . “contains helpful additions” here and there, but is chiefly remarkable for the copious extracts taken, in adapted form, from the dynastic histories and other sources.