John Duns Scotus

John Duns Scotus was the founder of a Scholastic branch called Scotism. His philosophy, although Aristotelian in origin, had certain basic differences with that of Thomas Aquinas -- founder of the more popular Scholastic school Thomism.

Duns Scotus believed that God does not command an action because He thinks it is good, rather, an action is good because that action is performed by God. Scotus was one of the most profound and subtle of the medieval theologians and was given the title "the Subtle Doctor" (Doctor Subtilis). Duns Scotus was a staunch defender of the concept of the Immaculate Conception, which was defined as dogma by Pope Pius IX in 1854.

His two best known works are On the First Principle and two commentaries on the Sentences of the Italian theologian Peter Lombard.

One source mentiones that a catalogue in the library of St Francis of Assisi """designates Duns Scotus's commentary on the "Sentences" of Peter Lombard as "magistri fratris Johannis Scoti de Ordine Minorum, qui et Doctor Subtilis nuncupatur, de provincia Hibernia" (the work of master John Scotus of the Franciscan Order known as the subtle doctor, from the province of Ireland)."""

Note that Scotland received its name from an Irish tribe that settled there. As an Irishman I am biased in the matter of his birthplace, but I guess no one will ever know.

In The history of philosophy of western Europe Bertrand Russell recounts how Scotus travelled to Rome and whilst there retaught the Romans Latin, a language which had almost been lost to them during the various sacks that Rome experienced under the barbarian invasions. I am not sure of the veracity of this story, but it is nice and allows me to say that the Irish saved civilisation (yay!)