"Plato had defined Man as an animal, biped and featherless, and was applauded. Diogenes plucked a fowl and brought it into the lecture-room with the words, "Here is Plato's man." "
Diogenes Laërtius, vi. 40
"A Socrates gone mad."
Plato, in Diogenes Laërtius, vi. 54, and Aelian, Varia Historia, xiv. 33
"This cynic did nothing but saboter the civilisation of the time. He was the nihilist of Hellenism. He created nothing, he made nothing." ~ José Ortega y Gasset