To arrive at perfection, a man should have very sincere friends or inveterate enemies; because he would be made sensible of his good or ill conduct, either by the censures of the one or the admonitions of the other.
I am Diogenes the Dog. I nuzzle the kind, bark at the greedy and bite scoundrels.
It takes a wise man to discover a wise man.
I am not an Athenian or a Greek, but a citizen of the world.
Even if I am but a pretender to wisdom, that in itself is philosophy.
The art of being a slave is to rule one's master.