DL 6.64 · Diogenes
When he was dining in a temple, and in the course of the meal loaves not free from dirt were put on the table, he took them up and threw them away, declaring that nothing unclean ought to enter a temple. To the man who said to him, "You don't know anything, although you are a philosopher," he replied, "Even if I am but a pretender to wisdom, that in itself is philosophy." When some one brought a child to him and declared him to be highly gifted and of excellent character, "What need then," said he, "has he of me?" Those who say admirable things, but fail to do them, he compared to a harp; for the harp, like them, he said, has neither hearing nor perception. 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."