What Kind of Problems Do Demons Solve?

This paper takes as a point of departure the contentions that Augustine invented the "inner self" as well as a new way of approaching the mind-body problem by way of a cogito-style argument, among others. It then argues that Augustine's late demonology, evident in City of God 21, marks a quiet and largely unnoticed revolution in the history of thinking about immaterial substances, and that Augustine's characteristic combination of religion and philosophy is essential to the revolution. Outside of Augustine, by contrast, demons and their bodies continued a different trajectory in both religious and philosophical contexts. It answers its title's question, then, with a predictable "all of the above."