You're mistaken; men of sense often learn much from their enemies. Prudence is the best safeguard. This principle cannot be learnt from a friend: but an enemy extorts it immediately. It is from their foes and not their friends, that cities learn the lesson of building high walls and ships of war. And this lesson saves their children, their homes, and their properties.
AristophanesThe children now love luxury; they have bad manners, contempt for authority; they show disrespect for elders and love chatter in place of exercise. Children are now tyrants, not the servants of their households. They no longer rise when elders enter the room. They contradict their parents, chatter before company, gobble up dainties at the table, cross their legs, and tyrannize their teachers.
Aristophanes