Those interested in the concept of ecstasy would be forgiven for assuming that a sober scholastic like St. Thomas Aquinas had little place for the idea. Yet in this groundbreaking study, sure to refine our understanding of the Angelic Doctor, Peter Kwasniewski shows that St. Thomas contemplates the nature of ecstasy at key stages in the development of his thought and that it plays a crucial role in his doctrine of love. After a stimulating study of treatments of ecstasy in ancient philosophy, Sacred Scripture, and the medieval tradition prior to Aquinas, Kwasniewski finds that he can be seen as breathing new life into the concept. While his contemporary, St. Bonaventure, for example, tended to restrict ecstasy to the soul’s union with God, St. Thomas admitted the place of ecstasy in a variety of human activities. Furthermore, St. Thomas recognized that all love involves ecstatic transcendence, whether it be the creature’s self-oblation to the Creator, the reverence of an inferior for a superior, a superior’s generosity toward an inferior, or the mutual affection and help of equals joined in friendship. Love of persons for their own sake generates an ecstatic love in which the self is borne as a gift to another subject by sharing a common life aspiring to common goods. Kwasniewski also examines Aquinas on the question of whether or not God experiences ecstasy, and if so, in what ways. The Ecstasy of Love in the Thought of Thomas Aquinas makes a significant contribution to our understanding of the doctrine of love and to the interpretation of the thought of St. Thomas Aquinas. It is more than an analysis of key texts; it is an illuminating guide to the grammar of ecstasy.