15. (3) By employing the officers of his army without discrimination,
That is, he is not careful to use the right man in the right place.
through ignorance of the military principle of adaptation to circumstances. This shakes the confidence of the soldiers.
I follow Mei Yao-ch‘ên here. The other commentators make 不知 etc. refer, not the the ruler, as in §§ 13, 14, but to the officers he employs. Thus Tu Yu says: 將若不知權變不可付以勢位 “If a general is ignorant of the principle of adaptability, he must not be entrusted with a position of authority.” Tu Mu quotes 黃石公: “The skilful employer of men will employ the wise man, the brave man, the covetous man, and the stupid man. For the wise man delights in establishing his merit, the brave man likes to show courage in action, the covetous man is quick at seizing advantages, and the stupid man has no fear of death.” The T‘ung Tien reads 軍覆疑, which Tu Yu explains as 覆敗 “is utterly defeated.” Capt. Calthrop gives a very inaccurate rendering: “Ignorant of the situation of the army, to interfere in its dispositions.”
16. But when the army is restless and distrustful, trouble is sure to come from the other feudal princes. This is simply bringing anarchy into the army, and flinging victory away.
Most of the commentators take 引 in the sense of 奪, which it seems to bear also in the Li Chi, 玉藻, I. 18. [卻 is there given as its equivalent, but Legge tries notwithstanding to retain the more usual sense, translating “draw... back,” which is hardly defensible.] Tu Mu and Wang Hsi, however, think 引勝 means “leading up to the enemy’s victory.”
17. Thus we may know that there are five essentials