Art of War 3.17

Chang Yü says: “If he can fight, he advances and takes the offensive; if he cannot fight, he retreats and remains on the defensive. He will invariably conquer who knows whether it is right to take the offensive or the defensive.”

This is not merely the general’s ability to estimate numbers correctly, as Li Ch‘üan and others make out. Chang Yü expounds the saying more satisfactorily: “By applying the art of war, it is possible with a lesser force to defeat a greater, and vice versâ. The secret lies in an eye for locality, and in not letting the right moment slip. Thus Wu Tzŭ says: ‘With a superior force, make for easy ground; with an inferior one, make for difficult ground.’”

Ts‘ao Kung refers 上下 less well to sovereign and subjects.

Tu Yu quotes 王子 as saying: 指授在君決戰在將也 “It is the sovereign’s function to give broad instructions, but to decide on battle is the function of the general.” It is needless to dilate on the military disasters which have been caused by undue interference with operations in the field on the part of the home government. Napoleon undoubtedly owed much of his extraordinary success to the fact that he was not hampered by any central authority, — that he was, in fact, 將 and 君 in one.

Literally, “These five things are knowledge of the principle of victory.”