Once Diogenes, who was washing vegetables, ridiculed him as he passed by, and said, "If you had learnt to eat these vegetables, you would not have been a slave in the palace of a tyrant." But Aristippus replied, "And you, if you had known how to behave among men, would not have been washing vegetables."
Aristippus, 4. - Book 2: Socrates, his predecessors and followers