  Godfrey of Fontaines was one of the major philosopher-theologians to serve as Regent Master at the University of Paris in the final quarter of the thirteenth century, along with Henry of Ghent and Giles of Rome. After completing philosophical studies in the Faculty of Arts and beginning to study theology probably by August, 1274, he became Regent Master in Theology in 1285 and retained this position until 1303/1304. His greatest contributions to philosophy were in the area of metaphysics. He was positively influenced by Thomas Aquinas, but differed with him on various major points, and also seems to have been influenced by the Arts Master, Siger of Brabant. His might well be described as a metaphysics of act and potency, since he often turns to this in seeking to resolve metaphysical problems such as, for instance, the relationship between essence and existence and between possible and actual being, the distinction between substance and accidents and between the soul and its powers, the causes of intellection and volition, or the nature of prime matter and its relationship to substantial form. Overall his philosophical thought and especially his metaphysics is somewhat more Aristotelian and less influenced by Neoplatonism than that of many of his contemporaries, including Aquinas.  