Page:Early Greek philosophy by John Burnet, 3rd edition, 1920.djvu/319

Rh what he supposed to be in the centre of our system. It seems clear too from the Laws that he must have attributed an axial rotation to the earth.

151. The existence of the antichthon was also a hypothesis intended to account for the phenomena of eclipses. In one place, indeed, Aristotle says the Pythagoreans invented it in order to bring the number of revolving bodies up to ten; but that is a mere sally, and Aristotle really knew better. In his work on the Pythagoreans, he said that eclipses of the moon were caused sometimes by the intervention of the earth and sometimes by that of the antichthon; and the same statement was made by Philip of Opous, a very competent authority on the matter. Indeed, Aristotle shows in another passage how the theory originated. He tells us that some thought there might be a considerable number of bodies revolving round the centre, though invisible to us because of the intervention of the earth, and that they accounted in this way for there being more eclipses of the moon than of the sun. This is mentioned in close connexion with the antichthon, so Aristotle clearly regarded the two hypotheses as of the same nature. The history of the theory seems to be this. Anaximenes had assumed the existence of dark 20