They are amusing fellows, said he (Epictetus), who are proud of the things which are not in our power.  A man says, I am better than you, for I possess much land, and you are wasting with hunger.  Another says, I am of consular rank.  Another says, I am a Procurator.  Another, I have curly hair.  But a horse does not say to a horse, I am superior to you for I possess much fodder, and much barley, and my bits are of gold and my harness is embroidered: but he says, I am swifter than you.  And every animal is better or worse from his own merit (virtue) or his own badness.  Is there then no virtue in man only?  and must we look to the hair, and our clothes and our ancestors?

(Epictetus, Enchiridion, XVI)