Kasser specializes in epistemology and the history of American pragmatism, with forays into philosophy of science and philosophy of religion. He is currently working out interpretations of Charles Peirce's doubt-belief theory of inquiry and of William James's expressivist approach to epistemic norms. He has published in such journals as Erkenntnis, European Journal of Philosophy, and Transactions of the Charles S. Peirce Society. He also wrote and delivered Philosophy of Science, a course produced for The Great Courses (formerly The Teaching Company).