Cato used to assert that wise men profited more by fools than fools by wise men; for that wise men avoided the faults of fools, but that fools would not imitate the good examples of wise men.
PlutarchWhen I myself had twice or thrice made a resolute resistance unto anger, the like befell me that did the Thebans; who, having once foiled the Lacedaemonians (who before that time had held themselves invincible), never after lost so much as one battle which they fought against them.
Plutarch