Question: W;hat ancient Greek philosopher died in 322 BC had testimony used in "On The Nature of Man"?
Context: The city of Athens (Ancient Greek: Ἀθῆναι, "Athênai" , "Athínai") during the classical period of Ancient Greece (508–322 BC) was the major urban center of the notable polis (city-state) of the same name, located in Attica, Greece, leading the Delian League in the Peloponnesian War against Sparta and the Peloponnesian League.  Athenian democracy was established in 508 BC under Cleisthenes following the tyranny of Isagoras.  This system remained remarkably stable, and with a few brief interruptions remained in place for 180 years, until 322 BC (aftermath of Lamian War).  The peak of Athenian hegemony was achieved in the 440s to 430s BC, known as the Age of Pericles. Xenophon of Athens ( ; Greek: Ξενοφῶν , "Xenophōn"; c. 430–354 BC) was an ancient Greek philosopher, historian, soldier, mercenary, and student of Socrates'.  As an historian, Xenophon is known for recording the history of his contemporary time, the late-5th and early-4th centuries BC, in such works as the "Hellenica", about the final seven years and the aftermath of the Peloponnesian War (431–404 BC); as such, the "Hellenica" is a thematic continuation of Thucydides' "History of the Peloponnesian War".  Also, as one of the Ten Thousand (Greek mercenaries), he participated in Cyrus the Younger's failed campaign to claim the Persian throne from his brother Artaxerxes II of Persia and recounted the events in "Anabasis", his most notable history, and like Plato (427–347 BC), Xenophon is an authority on Socrates, about whom he wrote the dialogue "Apology of Socrates to the Jury", which recounts the Trial of Socrates (399 BC). The Academy (Ancient Greek: Ἀκαδημία) was founded by Plato (428/427 BC – 348/347 BC) in ca. 387 BC in Athens.  Aristotle (384–322 BC) studied there for twenty years (367–347 BC) before founding his own school, the Lyceum.  The Academy persisted throughout the Hellenistic period as a skeptical school, until coming to an end after the death of Philo of Larissa in 83 BC.  Although philosophers continued to teach Plato's philosophy in Athens throughout the Roman era, it was not until 410 AD that a revived Academy was established as a center for Neoplatonism, persisting until 529 AD when it was finally closed by Justinian I. Aristotle ( ; Greek: Ἀριστοτέλης , , "Aristotélēs"; 384–322 BC) was an ancient Greek philosopher and scientist born in the city of Stagira, Chalkidice, on the northern periphery of Classical Greece.  His father, Nicomachus, died when Aristotle was a child, whereafter Proxenus of Atarneus became his guardian.  At seventeen or eighteen years of age, he joined Plato's Academy in Athens and remained there until the age of thirty-seven (c. 347 BC).  His writings cover many subjects – including physics, biology, zoology, metaphysics, logic, ethics, aesthetics, poetry, theater, music, rhetoric, linguistics, politics and government – and constitute the first comprehensive system of Western philosophy.  Shortly after Plato died, Aristotle left Athens and, at the request of Philip II of Macedon, tutored Alexander the Great beginning in 343 BC. 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.  It was written in the fourth century BC; Aristotle died in 322 BC. Demosthenes ( ; Greek: Δημοσθένης "Dēmosthénēs"; ] ; 384 – 12 October 322 BC) was a Greek statesman and orator of ancient Athens.  His orations constitute a significant expression of contemporary Athenian intellectual prowess and provide an insight into the politics and culture of ancient Greece during the 4th century BC.  Demosthenes learned rhetoric by studying the speeches of previous great orators.  He delivered his first judicial speeches at the age of 20, in which he argued effectively to gain from his guardians what was left of his inheritance.  For a time, Demosthenes made his living as a professional speech-writer (logographer) and a lawyer, writing speeches for use in private legal suits. Bolus of Mendes (Greek: Βῶλος "Bolos"; fl.  3rd century BC) was an ancient Greek philosopher, a neo-Pythagorean writer of works of esoterica and medical works, who worked in Ptolemaic Egypt.  The Suda, and Eudocia after him, mention a Pythagorean philosopher of Mendes in Egypt, who wrote on marvels, potent remedies, and astronomical phenomena.  The Suda, however, also describes a Bolus who was a philosopher of the school of Democritus, who wrote "Inquiry", and "Medical Art", containing "natural medical remedies from some resources of nature."  But, from a passage of Columella, it appears that Bolos of Mendes and the follower of Democritus were one and the same person; and he seems to have lived following the time of Theophrastus, whose work "On Plants" he appears to have known. On the Nature of Man is a work in the Hippocratic Corpus.  "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".  However, as with the many other works of the Hippocratic Corpus, the authorship is regarded as dubious in origin. Ariarathes I (Ancient Greek: Ἀριαράθης "Ariaráthēs"; died 322 BC) was the satrap of the Satrapy of Cappadocia under the Achaemenid Empire from 350 BC to 331 BC, and the King of Cappadocia from 331 BC until his death in 322 BC. Cleomenes (Greek: Kλεoμένης "Kleoménes"; died 322 BC), a Greek of Naucratis in Ptolemaic Egypt, was appointed by Alexander III of Macedon as nomarch of the Arabian district ("νoμoς") of Egypt and receiver of the tributes from all the nomes (districts) of ancient Egypt and the neighbouring part of Africa (331 BC).  Some of the ancient writers say that Alexander made him satrap of Egypt; but this is incorrect, for Arrian expressly states that the other nomarchs were independent of him, except that they had to pay to him the tributes of their districts.  It would, however, appear that he had no difficulty in extending his depredations over all Egypt, and it is possible that he would have taken the title of satrap.  It is told that his rapacity knew no bounds, that he exercised his office solely for his own advantage.
Answer: Aristotle