- 故明君賢將所以動而勝人成功出於衆者先知也
- 先知者不可取於鬼神不可象於事不可驗於度
- 必取於人知敵之情者也
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.
That is, knowledge of the enemy’s dispositions, and what he means to do.
5. 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. 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.”
