John Duns Scotus was probably born in the winter of 1266 in the South of Scotland. Around 1279 he was accepted in a Franciscan friary in South Scotland. After eight years of preliminary studies in philosophy, or rather in the artes, at Oxford, he started to study theology there in 1288. Having attained the age of 25 he was ordained a priest in Northampton on March 17th 1291.

In the academic year 1297-98 John Duns prepared his first theological course which would change his life. During the next year he gave this course, on the Sentences of Peter Lombard, the most important textbook of systematic theology at the time. During these years (1297-99) Duns wrote Lectura I-II, his lecture notes on the two first books of the Sentences. Scotus' course based on these notes not only impressed very much his audience, but also the Franciscan leadership, and established his name as an exceptionally penetrating and original thinker.

Just as Thomas Aquinas is the most famous theologian of the Dominican Order, John Duns Scotus is that of the Franciscan Order, the order of Francis of Assisi and Bonaventure. Since the 18th century the Vatican has promoted Thomas as the most important theologian of the Roman-Catholic church, which unjustifiably pushed Scotus into a second rank position.

Duns Scotus is well-known as an exceptionally bright theologian capable of very precise analysis of theological and philosophical issues. Although this is much less known, he also developed an overall consistent theological view. In discussion with colleagues in theology and philosophy Duns fully accepted the challenge of Aristotle's philosophy, which exercised an increasing influence on Christian theology.