The central position of St. Thomas Aquinas in the pantheon of Catholic thinkers along with St. Augustine of Hippo more than justifies ongoing attention to his thought and contributions to philosophy, theology and medieval culture. This volume is an anthology of the passages in his Summa Theologiae on human nature or the "Human Constitution as he calls it. The topics included in this series of texts such as the nature of the human soul, its relation to the body, the activities of the intellect and free will reflect the intellectual climate of St. Thomas' day. Despite this medieval context, however, these questions remain perennially fresh: what does it mean to be human? who are we? where do we come from? what makes us who we are? where are we going? All these and more receive clear and stimulating treatment in this careful selection and translation from Aquinas by Richard Regan.