History of Western Philosophy: Collectors Edition

by Bertrand Russell

Aristarchus of Samos found such a hypothesis: that all the planets, including the earth, go round the sun in circles. This view was rejected for two thousand years, partly on the authority of Aristotle, who attributes a rather similar hypothesis to ‘the Pythagoreans’ (De Coelo, 293a). It was revived by Copernicus, and its success might seem to justify Plato's aesthetic bias in astronomy. Unfortunately, however, Kepler discovered that the planets move in ellipses, not in circles, with the sun at a focus, not at the centre; then Newton discovered that they do not move even in exact ellipses. And so the geometrical simplicity sought by Plato, and apparently found by Aristarchus of Samos, proved in the end illusory.