Robert Audi's overall project has been to develop and refine a theory of rationality, theoretical and practical. On the theoretical side, he has worked in epistemology and neighboring parts of philosophy of mind: e.g., on the nature of belief, perception, and inference. On the practical side, his focus has been on action theory, ethics, and practical reason. He has developed a theory of reasons and rationality. In epistemology, he defends an internalist, direct realist, rationalist position. In ethics, he is a rationalist intuitionist. More recently, he has developed a liberal theory of religion and politics, and distinctive accounts of belief, desire, faith, intention, and practical reasoning.