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 愠 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.