Matthew Boyle works on topics in the philosophy of mind and moral psychology, especially self-knowledge, the nature of rationality, and some questions about the role of rationality in perception, motivation, and action. He also writes on topics in the history of philosophy, with a particular focus on the works of Immanuel Kant, although he also has interests in a variety of other figures, including Aristotle, Aquinas, Hegel, and Sartre.