The T‘ung Tien has 故能爲變化司命. Capt. Calthrop’s version of this paragraph is so remarkable that I cannot refrain from quoting it in full: “Now the secrets of the art of offence are not to be easily apprehended, as a certain shape or noise can be understood, of the senses; but when these secrets are once learnt, the enemy is mastered.”
10. 進而不可禦者衝其虛也退而不可追者速而不可及也
You may advance and be absolutely irresistible, if you make for the enemy’s weak points; you may retire and be safe from pursuit if your movements are more rapid than those of the enemy.
The second member of the sentence is weak, because 不可及 is nearly tautologous with 不可追. The Yü Lan reads 遠 for 速.
11. 故我欲戰敵雖高壘深溝不得不與我戰者攻其所必救也
If we wish to fight, the enemy can be forced to an engagement even though he be sheltered behind a high rampart and a deep ditch. All we need do is to attack some other place that he will be obliged to relieve.
Tu Mu says: “If the enemy is the invading party, we can cut his line of communications and occupy the roads by which he will have to return; if we are the invaders, we may direct our attack against the sovereign himself.” It is clear that Sun Tzŭ, unlike certain generals in the late Boer war, was no believer in frontal attacks.
12. 我不欲戰畫地而守之敵不得與我戰者乖其所之也
If we do not wish to fight, we can prevent the enemy from engaging us even though the lines of our encampment be merely traced out on the ground. All we need do is to throw something odd and unaccountable in his way.
In order to preserve the parallelism with [§ 11], I should prefer to follow the T‘u Shu text, which inserts 雖 before 畫地. This extremely concise expression is intelligibly paraphrased by Chia Lin: 雖未修壘壍 “even though we have constructed neither wall nor ditch.” The real crux of the passage lies in 乖其所之也. 之 of course = 至. Ts‘ao Kung defines 乖 by the word 戾, which is perhaps a case of obscurum per obscurius. Li Ch‘üan, however, says: 設奇異而疑之 “we puzzle him by strange and unusual dispositions;” and Tu Mu finally clinches the meaning by three illustrative anecdotes—one of 諸葛亮 Chu-ko Liang, who when occupying 陽平 Yang-p‘ing and about to be attacked by 司馬懿 Ssŭ-ma I, suddenly struck his colours, stopped the beating of the drums, and flung open the city gates, showing only a few men engaged in sweeping and sprinkling the ground. This unexpected proceeding had the intended effect; for Ssŭ-ma I, suspecting an ambush, actually drew off his army and retreated. What Sun Tzŭ is advocating here, therefore, is nothing more nor less than the timely use of “bluff.” Capt. Calthrop translates: “and prevent the enemy from attacking by keeping him in suspense,” which shows that he has not fully grasped the meaning of 乖.