Thomas Aquinas (1224/6–1274) lived an active, demanding academic and ecclesiastical life that ended while he was still comparatively young. He nonetheless produced many works, varying in length from a few pages to a few volumes. The Oxford Handbook of Aquinas is an introduction to this influential author and a guide to his thought on almost all the major topics on which he wrote. The book begins with an account of Aquinas's life and works. The next section contains a series of articles that set Aquinas in his intellectual context. They focus on the philosophical sources that are likely to have influenced his thinking, the most prominent of which were certain Greek philosophers (chiefly Aristotle), Latin Christian writers (such as Augustine), and Jewish and Islamic authors (such as Maimonides and Avicenna). The subsequent parts of the book address topics that Aquinas himself discussed. These include metaphysics, the existence and nature of God, ethics and action theory, epistemology, philosophy of mind and human nature, the nature of language, and an array of theological topics, including Trinity, Incarnation, sacraments, resurrection, and the problem of evil, among others. These articles include more than thirty contributions on topics central to Aquinas's own worldview. The final articles of the volume address the development of Aquinas's thought and its historical influence.