As Sun Tzŭ quotes this jingle in support of his assertion in § 15, we must suppose 修之 to stand for 修其功 or something analogous. The meaning seems to be that the ruler lays plans which the general must show resourcefulness in carrying out. It is now plainer than ever that 修 cannot mean “to reward.” Nevertheless, Tu Mu quotes the following from the 三略, ch.2: 霸者制士以權結士以信使士以賞信衰則士疏賞虧則士不用命 “The warlike prince controls his soldiers by his authority, knits them together by good faith, and by rewards makes them serviceable. If faith decays, there will be disruption; if rewards are deficient, commands will not be respected.”
17. Move not unless you see an advantage;
起, the Yü Lan’s variant for 動, is adopted by Li Ch‘üan and Tu Mu.
use not your troops unless there is something to be gained; fight not unless the position is critical.
Sun Tzŭ may at times appear to be over-cautious, but he never goes so far in that direction as the remarkable passage in the Tao Tê Ching. ch. 69: 吾不敢爲主而爲客不敢進寸而退尺 “I dare not take the initiative, but prefer to act on the defensive; I dare not advance an inch, but prefer to retreat a foot.”
18. No ruler should put troops into the field merely to gratify his own spleen; no general should fight a battle simply out of pique.
Again compare Lao Tzŭ, ch. 68: 善戰者不怒. Chang Yü says that 慍 is a weaker word than 怒, and is therefore applied to the general as opposed to the sovereign. The T‘ung Tien and Yü Lan read 軍 for 師, and the latter 合 for 致.
19. If it is to your advantage, make a forward move; if not, stay where you are.
This is repeated from XI. § 17. Here I feel convinced that it is an interpolation, for it is evident that § 20 ought to follow immediately on