Duns Scotus

John Duns Scotus was a Scottish Catholic priest and Franciscan friar who taught philosophy and theology at universities in the last decades of the 1200s. He developed the doctrine of univocity of being, the formal distinction as a method for parsing different aspects of the same thing, and the concept of haecceity - the property that makes each individual precisely what it is. He constructed a complex proof for God's existence and defended the Immaculate Conception of Mary. His penetrating style of argument earned him the title Doctor Subtilis, "the subtle doctor." He died on 8 November 1308. The school of thought that grew from his work became known as Scotism, and Pope John Paul II beatified him in 1993.