ABSTRACT
For over a century Heraclides of Pontus (4th century B.C.) has stood with Aristarchus of Samos (3rd century B.C.) as one of the ancient precursors of Copernicus. Heraclides is supposed to have advanced not only a hypothesis that the Earth rotates on its axis once a day but also the idea that the Sun as easily as the Earth may be a centre of planetary motion. There is, however, a very simple historical difficulty with this widely assumed view of Heraclides's planetary doctrines. Whereas Copernicus knew of Aristarchus's heliocentrical hypothesis,1 neither Copernicus nor Kepler nor anyone else before the nineteenth century put forth the name of Heraclides as an ancient heliocentrist.2 In an earlier study I have shown that the texts of Vitruvius, Pliny the Elder, and most especially Macrobius do not preserve any sort of Sun-centred or circumsolar path for either of the planets Mercury and Venus, while there is in the writing of Martianus Capella an unambiguous circumsolar theory for these two inner planets, which Martianus does not ascribe to any authority.3 The Capellan theory was recognized by Copernicus and Kepler and all writers on the subject of heliocentrism since the Renaissance. Where then does the name of Heraclides come from?
