“In war,” says Chang Yü, “if a spirit of anger can be made to pervade all ranks of an army at one and the same time, its onset will be irresistible. Now the spirit of the enemy’s soldiers will be keenest when they have newly arrived on the scene, and it is therefore our cue not to fight at once, but to wait until their ardour and enthusiasm have worn off, and then strike. It is in this way that they may be robbed of their keen spirit.” Li Ch‘üan and others tell an anecdote (to be found in the _Tso Chuan_, 莊公 year 10, § 1) of 曹劌 Ts‘ao Kuei, a _protégé_ of Duke Chuang of Lu. The latter State was attacked by Ch‘i, and the Duke was about to join battle at 長勺 Ch‘ang-cho, after the first roll of the enemy’s drums, when Ts‘ao said: “Not just yet.” Only after their drums had beaten for the third time, did he give the word for attack. Then they fought, and the men of Ch‘i were utterly defeated. Questioned afterwards by the Duke as to the meaning of his delay, Ts‘ao Kuei replied: “In battle, a courageous spirit is everything. Now the first roll of the drum tends to create this spirit, but with the second it is already on the wane, and after the third it is gone altogether. I attacked when their spirit was gone and ours was at its height. Hence our victory.” 吳子 (chap. 4) puts “spirit” first among the “four important influences” in war, and continues: 三軍之衆百萬之師張設輕重在於一人是謂氣機 “The value of a whole army—a mighty host of a million men—is dependent on one man alone: such is the influence of spirit!” a commander-in-chief may be robbed of his presence of mind. Capt. Calthrop goes woefully astray with “defeat his general’s ambition.” Chang Yü says: 心者將之所主也夫治亂勇怯皆主於心 “Presence of mind is the general’s most important asset. It is the quality which enables him to discipline disorder and to inspire courage into the panic-stricken.” The great general 李靖 Li Ching (A.D. 571–649) has a saying: 夫攻者不止攻其城擊其陳而已必有攻其心之術焉 “Attacking does not merely consist in assaulting walled cities or striking at an army in battle array; it must include the art of assailing the enemy’s mental equilibrium.” [問對, pt. 3.] 28. 是故朝氣銳晝氣惰暮氣歸 Now a soldier’s spirit is keenest in the morning; Always provided, I suppose, that he has had breakfast. At the battle of the Trebia, the Romans were foolishly allowed to fight fasting, whereas Hannibal’s men had breakfasted at their leisure. See Livy, XXI, liv. 8, lv. 1 and 8. by noonday it has begun to flag; and in the evening, his mind is bent only on returning to camp. 29. 故善用兵者避其銳氣擊其惰歸此治氣者也 A clever general, therefore, The 故, which certainly seems to be wanted here, is omitted in the _T‘u Shu_. avoids an army when its spirit is keen, but attacks it when it is sluggish and inclined to return. This is the art of studying moods. The _T‘ung Tien_, for reasons of 避諱 “avoidance of personal names of the reigning dynasty,” reads 理 for 治 in this and the two next paragraphs.