Professor Caston's research focuses primarily on ancient Greek and Roman philosophy, especially in philosophy of mind and metaphysics: he has published on the Presocratics and Sophists, Aristotle, the Stoics, and Augustine. He also has research interests in medieval philosophy and Austrian philosophy. He is currently at work on a book on the problem of intentionality in ancient philosophy, for Cambridge University Press. Professor Caston has been a receipient of fellowships from the NEH, the ACLS (the Frederick Burkhardt fellowship), the Center for Advanced Study in the Behavioral Sciences, and the Center for Hellenic Studies.

"The Spirit and the Letter: Aristotle on Perception." In Ricardo Salles (ed.), Metaphysics, Soul, and Ethics: Themes from the work of Richard Sorabji, 245–320. Oxford: Oxford University Press, 2004.

"Aristotle on Consciousness." Mind 111 (2002), 751–815.

"Something and Nothing: The Stoics on Concepts and Universals." Oxford Studies in Ancient Philosophy 17 (1999), 145–213.

"Aristotle and the Problem of Intentionality." Philosophy and Phenomenological Research 58 (1998), 249–98.

"Epiphenomenalisms, Ancient and Modern." The Philosophical Review 106 (1997), 309–63.