 Marsilius of Inghen, master at the Universities of Paris (1362–1378) and Heidelberg (1386–1396), wrote a number of treatises on logic, natural philosophy and theology popular at many late medieval and early modern universities. He adopted the logico-semantic approach of William of Ockham and John Buridan while at the same time defending the traditional views of Thomas Aquinas and Bonaventure. His thinking sheds light on the discussion between nominalists and realists and allows insight into the changing interests of philosophy and theology, from the critical attitude of many fourteenth-century authors to the search for tradition which was characteristic of the fifteenth century.