Etienne Gilson Reason and Revelation in the Middle Ages, first delivered as the Richard Lectures in 1937, was published in 1938 and became an immediate success. Not only does it contribute to a major question of debate in Christian, Jewish, and Islamic philosophy and religion in the medieval period but it also insists on the validity of truth obtainable through reason as well as revelation, on rational argument alongside religious faith. This message is as important in the twenty-first century as it was in the fourth century of the young Augustine, the thirteenth of St Thomas Aquinas, and the twentieth of the mature Gilson.--