If it is not advantageous, do not move. If objectives can not be attained, do not employ the army. Unless endangered, do not engage in warfare. The ruler cannot mobilize the army out of personal anger. The general cannot engage in battle because of personal frustration. When it is advantageous, move When not advantageous, stop. Anger can revert to happiness, annoyance can revert to joy, but a vanquished state cannot be revived The dead cannot be brought back to life.

Sun Tzu (545 – 470 B.C.E.)