οἱ μὲν ἄλλοι κύνες τοὺς ἐχθροὺς δάκνουσιν, ἐγὼ δὲ τοὺς φίλους, ἵνα σώσ — Diogenes of Sinope

"If you are to be kept right, you must possess either good friends or red-hot enemies. The one will warn you, the other will expose you."

"When asked why people give to beggars but not to philosophers, he replied, Because they expect they may become lame and blind, but never that they will become philosophers."

"He was going into a theatre, meeting face to face those who were coming out, and being asked why, "This," he said, "is what I practise doing all my life."

"When the slave auctioneer asked in what he was proficient, he replied, "In ruling people."

"When people laughed at him because he walked backward beneath the portico, he said to them: "Arent you ashamed, you who walk backward along the whole path of existence, and blame me for walking backward along the path of the promenade?"

"Aristotle dines when it seems good to King Philip, but Diogenes when he himself pleases."