- No ruler should put troops into the field merely to gratify his own spleen; no general should fight a battle simply out of pique.
- 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 § 18.]
- Anger may in time change to gladness; vexation may be succeeded by content.
- But a kingdom that has once been destroyed can never come again into being;
[The Wu State was destined to be a melancholy example of this saying.]
nor can the dead ever be brought back to life.
- Hence the enlightened ruler is heedful, and the good general full of caution. This is the way to keep a country at peace and an army intact.
[1] "Unless you enter the tiger’s lair, you cannot get hold of the tiger’s cubs."