Alcmaeon of Croton, one of the most emlinent natural philosophers of antiquity, was a native of Croton in Magna Graecia. His father's name was Pirithus, and he is said to have been a pupil of Pythagoras, and must therefore have lived in the latter half of the sixth century before Christ. (Diog. Laërt. viii. 83.) Nothing more is known of the events of his life. His most celebrated anatomical discovery has been noticed in the Dict. of Ant. p. 756, a; but whether his knowledge in this branch of science was derived from the dissection of animals or of human bodies, is a disputed question, which it is difficult to decide. Chalcidius, on whose authority the fact rests, merely says (Comment. in Plat. "Tim." p. 368, ed. Fabr.), " qui primus exsectionem aggredi est ausus," and the word cxsectio would apply equally well to either case. He is said also (Diog. Laërt. l. c.; Clemens Alexandr. Strom. i. p. 308) to have been the first person who wrote on natural philosophy (Phusikon logon), and to have invented fables (fabulas, Isid. Oriy. i. 39). He also wrote several other medical and philosophical works, of which nothing but the titles and a few fragments have been preserved by Stobaeus (Eclog. Phys.) Plutarch (De Phys. Philos. Decr.), and Galen. (Histor. Philosophy.) A further account of his philosophical opinions may be found in Menage's Notes to Diogenes Laërtius, viii. 83, p. 387; Le Clerc, Hist. de la Méd. ; Alfons. Ciacconius ap. Flbric, Biblioth. Graec. vol. xiii. p. 48, ed. vet.; Sprengel, Hist. de la Méd. vol. i. p. 239; C. G. Kühn, De Philosoph. ante Hippocr. Medicinae Cultor. Lips. 1781, 4to., reprinted in Ackermann's Opusc. ad Histor. Medic. Pertinentia, Norimb. 1797, 8vo., and in Kühn's Opusc. Acad. Med. et Philol. Lips. 1827-8, 2 vols. 8vo.; Isensec, Gesch. der Medicin. [W.A.G]

Although Alcmaeon is termed a pupil of Pythagoras, there is great reason to doubt whether he was a Pythagorean at all; his name seems to have crept into the lists of supposititious Pythagoreans given us by later writers. (Brandis, Geschichte der Philosophie, vol. i. p. 507.) Aristotle (Metaphys. 1) mentions him as nearly contemporary with Pythagoras, but distinguishes between the stoicheia of opposites, under which the Pythagoreans included all things, and the double principle of Alcmaeon, according to Aristotle, less extended, although he does not explain the precise difference. Other doctrines of Alcmaeon have been preserved to us. He said that the human soul was immortal and partook of the divine nature, because like the heavenly bodies it contained in itself a principle of motion. (Arist. de Anima, i. 2, p. 405; Cic. de Nat. Deor. i. 11.) The eclipse of the moon, which was also eternal, he supposed to arise from its shape, which he said was like a boat. All his doctrines which have come down to us, relate to physics or medicine; and seem to have arisen partly out of the speculations of the Ionian school, with which rather than the Pythagorean, Aristotle appears to connect Alcmaeon, partly front the traditionary lore of the earliest medical science. (Brandis, vol. i. p. 508.)

Aristotle, The History of Animals 1:

Furthermore, there is a portion of the head, whereby an animal hears, a part incapable of breathing, the "ear". I say "incapable of breathing", for Alcmaeon is mistaken when he says that goats inspire through their ears.

Alcmaeon of Croton

Greek Medicine By Charles Singer