Geocentric model was gradually superseded by the heliocentric model of Copernicus, Galileo, and Kepler. There was much resistance to the transition between these two theories. Some Christian theologians were reluctant to reject a theory that agreed with Biblical passages. Others felt a new, unknown theory could not subvert an accepted consensus for geocentrism. The geocentric model entered Greek astronomy and philosophy at an early point; it can be found in pre-Socratic philosophy. In the 6th century BC, Anaximander proposed a cosmology with Earth shaped like a section of a pillar (a cylinder), held aloft at the center of everything. The Sun, Moon,
Aristarchus of Samos to Aristarchus, "On the Sizes and Distances of the Sun and Moon", is based on a geocentric world view. It has historically been read as stating that the angle subtended by the Sun's diameter is two degrees, but Archimedes states in "The Sand Reckoner" that Aristarchus had a value of ½ degree, which is much closer to the actual average value of 32' or 0.53 degrees. The discrepancy may come from a misinterpretation of what unit of measure was meant by a certain Greek term in the text of Aristarchus. Aristarchus claimed that at half moon (first or last quarter