Abstract

Ptolemy's Almagest, a brilliant treatise on theoretical astronomy combined with a practical handbook for computation, includes many compromises to reconcile discordant observations. This defense of Ptolemy examines in some detail a critical case concerning the model for Venus, which has sometimes been used as evidence for Ptolemy's perfidy. There the Alexandrian astronomer demonstrated his ingenuity when orbital constraints made it impossible to obtain directly the observed configurations he might have preferred