 In the Middle Ages Pythagoras and Pythagorean philosophy were regarded as the height of Greek philosophical achievement, although, somewhat paradoxically Pythagoreanism was not still an active philosophy as were Platonism and Aristotelianism but instead belonged to an “imagined history” of philosophy (Hicks 2014, 420). The view of Pythagoreanism in the Middle Ages was heavily determined by three late ancient Latin writers: Calcidius, Macrobius and Boethius. It was in particular the mathematical Pythagoreanism of Nicomachus as transmitted by Boethius that determined the medieval picture of Pythagoras. In ethics, Christians were able to embrace some Pythagorean maxims such as the principle labeled Pythagorean by Boethius: “Follow God” (Consolation of Philosophy 1.4). Some attention was also paid to other Pythagorean symbola (see section 5.2 below). On the other hand the doctrine of metempsychosis with its idea that human beings were born again as animals was repugnant to Christian doctrine (John of Salisbury, Policraticus 7.10). When it comes to Pythagoras’ life it is crucial to recognize that Iamblichus’ and Porphyry’s lives of Pythagoras were not known in the Middle Ages so that Pythagoras’ activities were mostly known through passages from classical authors and church fathers (Hicks 2014, 421). Pythagoras was included in medieval encyclopedic works and was given particularly thorough treatment by Vincent of Beauvais (before 1200–1264) in his Speculum historiale (3.24–26), by John of Wales (fl. 1260–1283) in Compendiloquium (3.6.2) and in The Lives and Habits of the Philosophers ascribed to, but probably not actually composed by, Walter Burley (1275–1344; see Riedweg 2005, 129; Heninger 1974, 47; Hicks 2014, 421). 