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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, "Behold Plato's man!"

"Lives and Opinions of Eminent Philosophers, Book 6: The Cynics". Book by Diogenes Laërtius translated by R. D. Hicks, 1925.
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, Behold Plato's man!