William of Auxerre

William of Auxerre (c.1150-1231) was a thirteenth century theologian who taught at the University of Paris. He was also archdeacon of Beauvais. He acted as advisor to Gregory IX on a conflict between his University and the citizens of Paris, and was asked by the pope to prepare corrections of recent translations from the Arabic of Aristotle’s works. His commentary on the Sentences of Peter Lombard, Summa aurea, also dealt with issues overlooked by the Lombard. He is regarded as the first medieval theologian to have written systematic treatises on free will and natural law.