Part 63

4. 故明君賢將所以動而勝人成功出於衆者先知也

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. 先知者不可取於鬼神不可象於事不可驗於度

Now this foreknowledge cannot be elicited from spirits;

以禱祀 “by prayers or sacrifices,” says Chang Yü. 鬼 are the disembodied spirits of men, and 神 supernatural beings or “gods.”

it cannot be obtained inductively from experience,

Tu Mu’s note makes the meaning clear: 象, he says, is the same as 類 reasoning by analogy; 不可以他事比類而求 “[knowledge of the enemy] cannot be gained by reasoning from other analogous cases.”

nor by any deductive calculation.

Li Ch‘üan says: 夫長短闊狹遠近小大卽可驗之於度數人之情僞度不能知也 “Quantities like length, breadth, distance and magnitude, are susceptible of exact mathematical determination; human actions cannot be so calculated.”

6. 必取於人知敵之情者也

Knowledge of the enemy’s dispositions can only be obtained from other men.

Mei Yao-ch‘ên has rather an interesting note: 鬼神之情可以筮卜知形氣之 物可以象類求天地之理可以度數驗唯敵之情必由間者而後知也 “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. 故用間有五有鄉間有內間有反間有死間有生間

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. 五間俱起莫知其道是謂神紀人君之寳也

When these five kinds of spy are all at work, none can discover the secret system.

道 is explained by Tu Mu as 其情泄形露之道 “the way in which facts leak out and dispositions are revealed.”

This is called

爲 is the reading of the standard text, but the T‘ung Tien, Yü Lan and T‘u Shu all have 謂.

“divine manipulation of the threads.”

Capt. Calthrop translates 神紀 “the Mysterious Thread,” but Mei Yao-ch‘ên’s paraphrase 神妙之綱紀 shows that what is meant is the control of a number of 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.”

9. 鄉間者因其鄉人而用之

Having local spies

鄉間 is the emended reading of Chia Lin and the T‘u Shu for the unintelligible 因間, here and in § 7, of the standard text, which nevertheless reads 鄉間 in § 22.

means employing the services of the inhabitants of a district.