Leprosy and Inherited Diseases in 13th-Century Discussions on the Original Sin

This essay explores the theoretical treatment of leprosy in 13th-century theological discussions on the transmission of the original sin. According to scholastic theologians, both the existence of the original sin and its transmission from parents to progeny were factual truths, whose dynamics could be explained by analogy with inherited diseases, such as leprosy. Different uses of natural philosophy and medicine in discussing the transmission of leprosy will be shown in theological and biblical-exegetical works of William of Auvergne, Roland of Cremona, Bonaventure, Thomas Aquinas, and Henry of Ghent.