was a celebrated philosopher of Syracuse, who, according to Theophrastus, as quoted by Cicero, believed that the heavens, sun, and stars, remained still, and that it was the earth which moved and, by turning on its axis, produced the same appearance to us as if the heavens had turned and the earth had been immovable. Copernicus acknowledges that this passage in Cicero suggested to him the first idea of his system. Diogenes Laertius also mentions Hicetas. 2