Thomas Aquinas (1224/5-1274) is one of the most prominent figures in medieval philosophy. In fact, he is so prominent that many modern readers take his views, mistakenly, as the expression of what medieval philosophers in general say about a given topic. In this class we look at three key areas of Aquinas's teaching. We start with his views on human nature and psychology as they are developed in his main work, the Summa theologiae. Next we focus on his philosophy of action, including his account of virtues and vices and moral goodness, before we end with an exploration of some issues in Aquinas's teaching on metaphysics.