In order to understand how theology is a science for St. Thomas Aquinas, it is necessary, first, to understand what he means by "science." In contrast to the dominant view in the academy today, Aquinas did not hold that scientific knowledge is possible only through empirical means, that is, only through the action of one or more of the five physical senses. In this lecture, Dr. Sirilla explains that Aquinas' understanding of science corrects and supplements the opinion that science is exclusively empirical. Aquinas' epistemology enables us to identify sciences that are not limited to sense-data, such as metaphysics and theology. BIO: Dr. Michael Sirilla is an Assistant Professor of Theology at the Franciscan University of Steubenville. He received his Ph.D. in systematic theology from The Catholic University of America in May, 2008. His dissertation is entitled, “St. Thomas Aquinas’s Theology of the Episcopacy in his Commentaries on the Pastoral Epistles.” This work is currently under review for publication. In addition to the theology of the episcopacy, his research interests include the natural knowledge of God’s existence and attributes, the theology of grace and justification, and the distinction among different kinds of magisterial pronouncements and the corresponding types of assent required by each.