William of Auxerre (Guillelmus Altissiodorensis, c. 1150–1231) was a French scholastic theologian and master at the University of Paris in the first decades of the thirteenth century, and archdeacon of Beauvais. His Summa aurea, composed in the 1220s, is one of the earliest systematic theological summae and an important transitional work between Peter Lombard's Sentences and the great Dominican and Franciscan summae of the mid-thirteenth century; it was widely read and influenced Alexander of Hales, Albert the Great, and Thomas Aquinas. He was among the first scholastics to make extensive theological use of the newly available Aristotelian corpus. In 1231 he was appointed by Gregory IX to the commission charged with examining and expurgating Aristotle's natural philosophy, but died in Rome that same year before the work could begin.
