AbstractMediaeval psychological theory was a “faculty psychology”: a confederation of semiautonomous sub-personal agents, the interaction of which constitutes our psychological experience. One such faculty was intellective appetite, that is, the will. On what grounds was the will taken to be a distinct faculty? After a brief survey of Aristotle's criteria for identifying and distinguishing mental faculties, I look in some detail at the mainstream mediaeval view, given clear expression by Thomas Aquinas, and then at the dissenting views of John Duns Scotus and William of Ockham. I conclude with some reflections on why the mainstream mediaeval view was discarded by Descartes.
