Featherless

After Plato defined a human as a "featherless biped," Diogenes plucked a chicken and brought it into the Academy. "Behold," he said, "a human!"

A man is a featherless biped.

Man is a featherless biped.

There's a famous story that Plato defined a human as a featherless biped. In response, another philosopher, Diogenes, plucked all the feathers off a chicken and sarcastically declared it a man, proving Plato wrong.

He eyed me with contempt: great featherless, half winged bird as I was, incomprehensible, contemptible, but awful.

[…] clad in a featherless hat and somber black garments, which set off the dark pallor of his forbidding face.