The form of this paragraph reminds us that Sun Tzŭ’s treatise was composed expressly for the benefit of his patron 闔閭 Ho Lü, king of the Wu State. It is not necessary, however, to understand 我 before 留之 (as some commentators do), or to take 將 as “generals under my command.”
16. 計利以聽乃爲之勢以佐其外
While heeding the profit of my counsel, avail yourself also of any helpful circumstances over and beyond the ordinary rules.
Capt. Calthrop blunders amazingly over this sentence: “Wherefore, with regard to the foregoing, considering that with us lies the advantage, and the generals agreeing, we create a situation which promises victory.” Mere logic should have kept him from penning such frothy balderdash.
17. 勢者因利而制權也
According as circumstances are favourable, one should modify one’s plans.
Sun Tzŭ, as a practical soldier, will have none of the “bookish theoric.” He cautions us here not to pin our faith to abstract principles; “for,” as Chang Yü puts it, “while the main laws of strategy can be stated clearly enough for the benefit of all and sundry, you must be guided by the actions of the enemy in attempting to secure a favourable position in actual warfare.” On the eve of the battle of Waterloo, Lord Uxbridge, commanding the cavalry, went to the Duke of Wellington in order to learn what his plans and calculations were for the morrow, because, as he explained, he might suddenly find himself Commander-in-chief and would be unable to frame new plans in a critical moment. The Duke listened quietly and then said: “Who will attack the first to-morrow—I or Bonaparte?” “Bonaparte,” replied Lord Uxbridge. “Well,” continued the Duke, “Bonaparte has not given me any idea of his projects; and as my plans will depend upon his, how can you expect me to tell you what mine are?”[[168]]
18. 兵者詭道也
All warfare is based on deception.
The truth of this pithy and profound saying will be admitted by every soldier. Col. Henderson tells us that Wellington, great in so many military qualities, was especially distinguished by “the extraordinary skill with which he concealed his movements and deceived both friend and foe.”