“In my opinion, however, disasters such as these teach men this lesson with regard to anger: one ought not to punish even a slave in anger; for masters who have lost their tempers often do more harm to themselves than they inflict; but in dealing with enemies it is utterly and entirely wrong to launch an attack under the influence of anger and without deliberation. Anger does not look ahead, whereas deliberation is just as concerned with avoiding harm oneself as with inflicting it on the enemy.” (Xenophon, 1978, p.272-273).
Xenophon was a Greek historian and philosopher whose numerous surviving works are valuable for their depiction of late Classical Greece. His Anabasis (“Upcountry March”) in particular was highly regarded in antiquity and had a strong influence on Latin literature.
Xenophon., Radice, B. (ed) & Warner, R. (Trans) (1979) Xenophon: A History of My Times. London: Penguin Books Ltd.