W;hat ancient Greek philosopher died in 322 BC had testimony used in "On The Nature of Man"?
On the Nature of Man:  "On the Nature of Man" is attributed to Polybus, the son in law and disciple of Hippocrates, through a testimony from Aristotle's "History of Animals". History of Animals: History of Animals (Greek: Τῶν περὶ τὰ ζῷα ἱστοριῶν , Ton peri ta zoa historion, "Inquiries on Animals"; Latin: "Historia Animālium" "History of Animals") is one of the major texts on biology by the ancient Greek philosopher Aristotle, who had studied at Plato's Academy in Athens. History of Animals:  It was written in the fourth century BC; Aristotle died in 322 BC.
Aristotle