Born in Scotland, Duns Scotus (c. 1265/1266-1308) became a monk at a very young age. We do not know the precise date of his birth, but we do know that Scotus was ordained to the priesthood in the Order of Friars Minor at Saint Andrew's Priory in Northampton, England, on March 17, 1291. He later taught at Paris as a commentator on the books of the Sentences of Peter Lombard. He also taught at Oxford, Canterbury and Cologne.
‘Scotus' is a nickname: it identifies Scotus as a Scot. His family name was Duns, which was also the name of the Scottish village in which he was born, just a few miles from the English border.
John Duns Scotus was one of the most important and influential philosopher-theologians of the High Middle Ages. His brilliantly complex and nuanced thought which earned him the nickname "the Subtle Doctor," left a mark on discussions of such disparate topics as the semantics of religious language, the problem of universals, divine illumination, and the nature of human freedom.
In June 1303 Scotus was expelled from France along with eighty other friars for taking the Pope's side in a dispute with the king. They were allowed to return in April 1304; it appears that Scotus completed his lectures on the Sentences not long thereafter.
On November 18, 1304 Scotus was appointed the Franciscan regent master in theology at Paris. For reasons no one quite understands, Scotus was transferred to the Franciscan studium at Cologne, probably beginning his duties as lector in October 1307.
Duns Scotus's teaching is orthodox. Catholics and Protestants alike have charged him with sundry errors and heresies; the Church has not condemned a single proposition of his. On the contrary, the doctrine of the Immaculate Conception, which he so strongly advocated, has been declared a dogma. At the time, there was a great deal of argument about the subject.
The general opinion was that it was appropriate, but it could not be seen how to resolve the problem that only with Christ's death would the stain of original sin be removed. Citing Anselm of Canterbury's principle, "potuit, decuit, ergo fecit" (God could do it, it was appropriate, therefore he did it), Duns Scotus devised the following argument: Mary was in need of redemption like all other human beings, but through the merits of Jesus' crucifixion, given in advance, she was conceived without the stain of original sin.
Blessed John Duns Scotus died in Cologne, Germany in 1308; the date of his death is traditionally given as November 8. He was beatified by Pope John Paul II on March 20, 1993.
See Dun Scotus's Oxford, by Gerard Manley Hopkins