Blessed John Duns Scotus (†1308), "Duns the Scot" (†1308) was a Scottish Catholic priest and Franciscan friar, university professor, philosopher, and theologian. He is one of the four most important Christian philosopher-theologians of Western Europe in the High Middle Ages. Duns Scotus has had considerable influence on both Catholic and secular thought. The doctrines for which he is best known are the "univocity of being," that existence is the most abstract concept we have, applicable to everything that exists; the formal distinction, a way of distinguishing between different formalities of the same thing; and the idea of haecceity, the property supposed to be in each individual thing that makes it an individual. Duns Scotus also developed a complex argument for the existence of God and argued for the Immaculate Conception of Mary. The intellectual tradition derived from Scotus' work is called Scotism. Duns Scotus was given the scholastic accolade of Doctor Subtilis ("the subtle doctor") for his penetrating and subtle manner of thought. He was beatified by Pope John Paul II on March 20, 1993 and his Feast Day is commemorated on 8 November.