Arguably the most influential work of systematic theology in the history of Christianity, Thomas Aquinas' Summa Theologiae has shaped all subsequent theology since it was written in the late thirteenth century. This Companion features essays from both specialists in Aquinas' thought and from constructive contemporary theologians to demonstrate how to read the text effectively and how to relate it to past and current theological questions. The authors thoroughly examine individual topics addressed in the Summa, such as God, the Trinity, eternity, providence, virtue, grace, and the sacraments, making the text accessible to students of all levels. They further discuss the contextual, methodological, and structural issues surrounding the Summa, as well as its interaction with a variety of religious traditions. This volume will not only allow readers to develop a comprehensive multi-perspectival understanding of Aquinas' main mature theological work, but also promote dialogue about the vital role of the Summa in theology today. 'The collection is exactly what it sets out to be: a varied and helpful introduction to a major milestone in Western theology …' Gerard J. Hughes SJ, The Way 'This Cambridge Companion succeeds in offering a thorough introduction to the Summa, which continues to cast a long shadow over twenty-first century thought. It is sure to entice the study of the Summa itself.' Christopher A. Stephenson, Religious Studies Review This Companion offers an accessible, comprehensive guide to the contents, context, and enduring influence of Thomas Aquinas' Summa Theologiae. Philip McCosker is Director of the Von Hügel Institute and Fellow of St Edmund's College, University of Cambridge, and Departmental Lecturer in Modern Theology, University of Oxford. He is the editor of What Is It that the Scripture Says? (2006) and author of Christ the Paradox: Expanding Ressourcement Theology (2016). He is also the editor of the journal Reviews in Religion and Theology. Denys Turner is Horace Tracy Pitkin Professor Emeritus of Historical Theology at Yale University. His most recent publications include Julian of Norwich, Theologian (2011) and Thomas Aquinas: A Portrait (2013).