Li Ch‘üan cites the case of 苻堅 Fu Chien, prince of 秦 Ch‘in, who in 383 A.D. marched with a vast army against the 晉 Chin Emperor. When warned not to despise an enemy who could command the services of such men as 謝安 Hsieh An and 桓沖 Huan Ch‘ung, he boastfully replied: “I have the population of eight provinces at my back, infantry and horsemen to the number of one million; why, they could dam up the Yangtsze River itself by merely throwing their whips into the stream. What danger have I to fear?” Nevertheless, his forces were soon after disastrously routed at the 淝 Fei River, and he was obliged to beat a hasty retreat. If you know neither the enemy nor yourself, you will succumb in every battle. The modern text, represented by the 北堂書鈔 and _T‘u Shu_, has 必敗, which I should be inclined to adopt in preference to 殆 here, though the _T‘ung Tien_ and _Yü Lan_ both have the latter. Chang Yü offers the best commentary on 知彼知己. He says that these words “have reference to attack and defence: knowing the enemy enables you to take the offensive, knowing yourself enables you to stand on the defensive.” He adds: 攻是守之機守是攻之策 “Attack is the secret of defence; defence is the planning of an attack.” It would be hard to find a better epitome of the root-principle of war. IV. 形篇 TACTICAL DISPOSITIONS. 形 is a very comprehensive and somewhat vague term. Literally, “form,” “body,” it comes to mean “appearance,” “attitude” or “disposition;” and here it is best taken as something between, or perhaps combining, “tactics” and “disposition of troops.” Ts‘ao Kung explains it as 軍之形也，我動彼應兩敵相察情也 “marching and counter-marching on the part of the two armies with a view to discovering each other’s condition.” Tu Mu says: “It is through the 形 dispositions of an army that its condition may be discovered. Conceal your dispositions (無形), and your condition will remain secret, which leads to victory; show your dispositions, and your condition will become patent, which leads to defeat.” Wang Hsi remarks that the good general can 變化其形因敵以制勝 “secure success by modifying his tactics to meet those of the enemy.” In the modern text, the title of the chapter appears as 軍形, which Capt. Calthrop incorrectly translates “the order of battle.” 1. 孫子曰昔之善戰者先爲不可勝以待敵之可勝 Sun Tzŭ said: The good fighters of old first put themselves beyond the possibility of defeat, and then waited for an opportunity of defeating the enemy. 2. 不可勝在己可勝在敵 To secure ourselves against defeat lies in our own hands, but the opportunity of defeating the enemy is provided by the enemy himself. That is, of course, by a mistake on his part. Capt. Calthrop has: “The causes of defeat come from within; victory is born in the enemy’s camp,” which, though certainly an improvement on his previous attempt, is still incorrect. 3. 故善戰者能爲不可勝不能使敵必可勝