Aristotle,
Politics — Book Seven
“ A city therefore ought to be temperate, brave, and patient; for, according to the proverb, "Rest is not for slaves;" but those who cannot bravely face danger are the slaves of those who attack them. Bravery, therefore, and patience are necessary for labour, philosophy for rest, and temperance and justice in both; but these chiefly in time of peace and rest; for war obliges men to be just and temperate; but the enjoyment of pleasure, with the rest of peace, is more apt to produce insolence ”
