Duns Scotus

John Duns Scotus (c. 1265/1266–1308), known as the "Subtle Doctor," was a Scottish Franciscan friar and one of the most influential philosophers and theologians of the High Middle Ages. Educated at Oxford, Cambridge, and Paris, he developed a sophisticated metaphysical system that challenged Thomistic Aristotelianism, most notably through his doctrine of the univocity of being — the argument that "being" is predicated in the same sense of both God and creatures — and his concept of haecceity, the individuating principle that makes each thing the particular thing it is. He championed the doctrine of the Immaculate Conception of Mary with rigorous philosophical arguments at a time when it remained disputed, a position the Catholic Church formally defined in 1854. His theology emphasized the primacy of the will and divine freedom, making him a forerunner of voluntarist traditions, and his defense of the primacy of Christ (the Incarnation as willed independently of the Fall) became a hallmark of Franciscan Christology. Scotism remained a distinct and vital scholastic school alongside Thomism well into the early modern period.