On Rewards and Punishments (137-138)

Again. To free-born people slavery is a most intolerable evil, to avoid which wise men are willing even to die, resisting in a gallant spirit which despises all danger the attacks of those who seek to inflict upon them the domination of a master. Also, an invincible enemy is an intolerable evil. And if the same person be both things at once, namely, a master and an enemy, who can endure such a complication of calamities? For such a person will be possessed of the power of inflicting injury through his authority as a master, and he will be disinclined to pardon any one by reason of his irreconcileable

Therefore the lawgiver pronounces that those persons who neglect the sacred laws shall have their enemies for their masters, who will treat them unmercifully, not only as having been reduced under their power by invincible attacks, but also as having voluntarily submitted to them through unforeseen calamities which famine and the want of necessaries has caused; for some persons think it well to choose lesser evils, if by so doing they can avoid greater ones; if, indeed, any one of the misfortunes above mentioned can be called a slight evil.