12. 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.
13. By discovering the enemy’s dispositions and remaining invisible ourselves, we can keep our forces concentrated, while the enemy’s must be divided.
The conclusion is perhaps not very obvious, but Chang Yü (after Mei Yao-ch‘ên) rightly explains it thus: “If the enemy’s dispositions are visible, we can make for him in one body; whereas, our own dispositions being kept secret, the enemy will be obliged to divide his forces in order to guard against attack from every quarter.” 形 is here used as an active verb: “to make to appear.” See IV, note on heading. Capt. Calthrop’s “making feints” is quite wrong.