This book is a detailed introduction to and discussion of Thomas Aquinas's best-known and most influential work: the Summa Theologiae. After a scholarly account of Aquinas's life, the book explores his purposes in writing the Summa Theologiae and provides a detailed analysis of each of its three parts.

Preface ; 1. Setting the Summa Theologiae ; 2. Sacred Teaching (1a,1) ; 3. Knowing That God Exists (1a,1,2) ; 4. The Divine Nature: Part 1 (1a,3-13) ; 5. The Divine Nature: Part 2 (1a,14-26) ; 6. The Divine Trinity (1a,27-43) ; 7. Creation, Good, and Evil (1a,44-49) ; 8. Angels and the Days of Creation (1a,50-74) ; 9. Human Beings and Divine Government (1a,75-119) ; 10. Happiness, Human Action, and Morality (1a2ae,1-21) ; 11. Emotions (1a2ae,22-48) ; 12. Dispositions, Virtues, Gifts, Beatitudes and Fruits (1a2ae,49-70) ; 13. Sin (1a2ae,71-85) ; 14. Law, Old Law, New Law, and Grace (1a2ae,90-114) ; 15. Faith, Hope, and Charity (2a2ae,1-46) ; 16. Prudence, Justice, and Injustice (2a2ae,47-79) ; 17. Religion and Other Matters to do With Justice (2a2ae,80-122) ; 18. Courage and Temperance (2a2ae,123-170) ; 19. Freely Given Graces, Kinds of Life, and States of Life (2a2ae,171-189) ; 20. God Incarnate (3a,1-26) ; 21. The Life, Death, Resurrection, and Ascension of Christ (3a,27-59) ; 22. The Sacraments of the Christian Church (3a,60-90) ; 23. Epilogue ; Appendix: The Summa Theologiae at a Glance ; Bibliography ; Index

"The most striking thing about this book is its completeness. It is indeed an introductory guide to and a (brief) commentary on the whole of the Summa Theologiae -- the whole of the Summa Theologiae... The book is intended as an introductory guide and commentary, and perhaps few of those who read it will get as far as reading the whole Summa. But those who read this book will be far better equipped to understand the fragments which they do get to read in the context of St. Thomas's mature thought as a whole. And for anyone who has merely to dip into the Summa from time to time, reading or re-reading the sections of this book that deal with what he or she is unfamiliar with will be a small effort and a brief time well spent in the best possible preparation." --Notre Dame Philosophical Reviews "...[A] scholarly triumph... [This book] is thorough, well organized, and supplemented with copious notes and pie charts that give a visual breakdown of the philosophical and theological subjects covered in the Summa... those looking for a comprehensive and accessible companion to Aquinas's Summa could do no better... Essential." --CHOICE "Brian Davies takes the reader on a guided tour of the vast demesne of the Summa Theologiae with a lucid and patient commentary. He writes for the intelligent reader without any formal training in either philosophy or theology--the kind of audience, he believes, that St. Thomas himself had in mind. Nonetheless, his book contains a number of surprises even for those who are familiar with the landscape." --Anthony Kenny, author of the four-volume series New History of Western Philosophy "Most of us engaged in studying Christian theology would of course say that Thomas Aquinas's Summa Theologiae is a classic, an essential text, which we should all read and re-read. The truth is, however, that, while the clarity of the arguments and the systematic presentation are very attractive, most newcomers and even old hands need a good deal of help to keep going: no one is better qualified than Brian Davies, after years of teaching and writing about it, to guide us: the study of the Summa will be greatly facilitated and enriched by this excellent commentary." --Fergus Kerr, OP, Honorary Fellow, School of Divinity, University of Edinburgh

Brian Davies is Professor of Philosophy at Fordham University and Honorary Professor at Australian Catholic University. He has published numerous books on Aquinas, including Thomas Aquinas on God and Evil (OUP 2011).