Thomas D. Sullivan

Thomas D. Sullivan is an American philosopher long associated with the University of St. Thomas (Minnesota), where he held the Aquinas Chair in Philosophy and Theology. Trained in the analytic tradition while sympathetic to Thomistic metaphysics, he has worked across ethics, applied ethics, and philosophy of religion, publishing on topics ranging from the doctrine of double effect to natural theology and the epistemology of religious belief.

His most prominent contribution to philosophy of religion is The Agnostic Inquirer: Revelation from a Philosophical Standpoint (2011), co-authored with Sandra Menssen. The book argues, against a widespread philosophical assumption, that one need not first establish the existence of God through natural theology before rationally examining the content of purported revelations; rather, the content of a candidate revelation can itself contribute evidentially to the case for theism. This reverses the conventional ordering of natural theology and revealed theology and engages debates in religious epistemology associated with figures such as Richard Swinburne, Alvin Plantinga, and J. L. Schellenberg.

Sullivan's work has been discussed within Catholic analytic philosophy and by critics of evidentialist apologetics who question whether revelation can carry independent probative weight. He has also contributed to debates on moral absolutes, intention, and the ethics of killing, situating his philosophy of religion within a broader natural-law framework.