 More clear is Gregory’s importance in the late Middle Ages and Reformation, even if much of this period has received relatively little attention. Gregory’s impact is obvious, because many scholastics after 1350 copied large passages from his works, including such prominent figures as the Cistercian James of Eltville, Pierre d’Ailly, and Henry of Langenstein. Other important thinkers, such as Hugolino of Orvieto OESA, the Cistercian Pierre Ceffons, Marsilius of Inghen, and Peter of Candia OFM (Pope Alexander V) knew Gregory’s ideas well and cited them often. Few if any philosophers in the later fourteenth century can have been unaffected by his ideas, and for many he was their main inspiration. Gregory’s impact both inside and outside the Augustinian Order continued into the fifteenth century. The common Sentences commentary (the so-called Quaestiones communes) of the University of Vienna in the first half of the century was largely based directly or indirectly on Gregory’s thought, often duplicating his words (see recently, Schabel 2020). In the celebrated quarrel over future contingents at the University of Louvain (1465–1474), several of the participants cited Gregory’s position or even adopted it without attribution. Of course, the fact that only books I and II of Gregory’s commentary circulated means that Gregory’s direct impact is to be found in topics discussed in those books rather than in issues covered in books III and IV, such as the Immaculate Conception and the Eucharist, which had their own philosophical sub-issues.