Parmenĭdes

, a Greek philosopher of Elis, who flourished about 505 years before Christ. He was son of Pyres of Elis, and the pupil of Xenophanes, or of Anaximander, according to some. He maintained that there were only two elements, fire and the earth; and he taught that the first generation of men was produced from the sun. He first discovered that the earth was round, and habitable only in the two temperate zones, and that it was suspended in the centre of the universe, in a fluid lighter than air, so that all bodies left to themselves fell on its surface. There were, as he supposed, only two sorts of philosophy,—one founded on reason, and the other on opinion. He digested this unpopular system in verses, of which a few fragments remain. Diogenes Laërtius.