The Trinity is the fount of all mysteries of the Christian faith. Yet by the end of the 20^th century there was a noticeable dearth of writing about the Trinity. This beautifully produced volume with 43 articles of uniformly the highest standard, relating the most elevated of Christian mysteries to many areas of Christian life (prayer, politics, art and social relations), lets us know that this situation has now been more than remedied by providing a survey of the latest scholarship about the Trinity from an array of Catholic, Reformed and Orthodox scholars. The overall plan of the book, divided into seven sections covering Scripture, the Patristic age, Medieval and Modern theology, Systematic theology, Prayer and Contemporary Issues, could hardly be bettered. This handbook goes a long way towards implementing the plea made by von Balthasar in 1952 that all courses of theology be presented with a Trinitarian perspective.

In the opening section on the Trinity in Scripture Khaled Anatolios informs us that the Trinity was a criterion for deciding the canon and shows that revelation of the Trinity fulfils the history of salvation set out in the Old Testament. Karin Rowe and Mark Edwards present Hebrews as an unexpected source for Trinitarian doctrine. Rowe also shows us that ‘Trinitarian grammar’ is presupposed for any proper understanding of St. Paul's letters. Ben Witherington III junior, in a detailed examination of the Trinity in St John's Gospel, shows convincingly that the Trinity was not a construction of the post-apostolic Church but already embedded in the New Testament.

One of the things that struck me in reading this book was how little progress was made in enunciating a clear doctrine of the Trinity in the 2^nd and 3^rd centuries. This of course was quickly put right in the 4^th century. J. Warren-Smith's article, while it barely discusses the theological issues, provides a most useful historical account of the Arian controversy. Lewis Ayres, in his article on St Augustine, starts with the Word and shows that the Trinity preserves the simplicity of God (the Father and the Son are one in St John), also how arguments not always central in Augustine were developed later by Aquinas and Hegel. Byzantine theology is well represented with four contributions (cc. 8, 10, 15 and 23). I thought that more could have been said specifically about the thought of Athanasius and the Cappadocians in this Patristic section, but these omissions were well emended in later contributions.

In the section on medieval theology, Joseph Wawrykow provides a clear comparison of the differences between St Bonaventure and Aquinas on the Trinity. Wawrykow also gives a useful analysis of Aquinas’ Contra Gentiles IV cc. 1 – 25, which is more scriptural than the Summa on the Trinity. Karl Felmy supplies an historical account of the controversy about the Filioque clause, suggesting that it was introduced in Spain in 589 as the only way to overthrow the Arians, and elucidates well the political and theological reasons which led to the Schism in 1054. A fundamental cause of the disagreement about the Filioque was that the West went from the love of the Father and the Son while the East started with the monarchia.

The section on the Modern period includes articles on the impact of philosophy on theology of the Trinity (idealism by Cyril O'Regan, who gives a clear exposition of Hegel, and analytic philosophy by Fergus Kerr). The article by Vincent Holzer provides a panorama of developments in Trinitarian theology of the 20^th century, particularly by Karl Rahner, explaining his dispute with von Balthasar about the economic and immanent Trinity. Holzer tells us that Rahner linked the Trinity with the tract on grace through the influence of Blondel and deplored the isolation of the Trinity from the missions of the Son and the Holy Spirit. The influence of Congar's three volumes on the Holy Spirit is noted among the new impulses in the 20^th century, linking the Trinity with creation (the special province of Gilles Emery) and the unity of the Church. This is followed by an article by A. Papinikolaou discussing Zizioulas, who situates the doctrine of the Trinity in experience of Christ and the Holy Spirit in the Eucharist.

Several articles in the dogmatic section were the highlight of the book for me. Kathryn Tanner, in an article showing that Scripture is indeed the soul of theology, and with well chosen quotations from Athanasius and Hilary, points to the Christological direction of Trinitarian doctrine in the early centuries. Rudi Te Velde discusses how we can speak of ‘persons’ in God with a fine analysis of Aquinas on analogy, an idea lacking in Augustine. In a splendid, brisk article, Tom Weinandy succinctly brings out the implications of Nicea, takes us back to Irenaeus and Athanasius on creation through the Word and Image of God, shows most usefully how the Son was related to the Spirit in his life on earth, and shows the relation between Augustine and Aquinas on the Trinity. Bruce Marshall also gives a masterful account of the Catholic tradition stretching from the Cappadocians through Augustine to Aquinas, in an article which is a model of readable prose containing a high amount of clear theological discussion focussing on the Holy Spirit as Love and Gift. His phrase that the love with which we love God is a sharing in the love with which the Father loves the Son and the Son the Father is memorable.

For the rest, Charles Morerod shows how one's view of the Trinity can affect one's ecclesiology (Calvinist and Orthodox included). Francesca Murphy, with imaginative use of her literary sources, traces Trinitarian prayer from the patristic to modern age, and makes up for what is surely an oversight of Newman in this collection. Verna Harrison uses the Church Fathers to allay feminist fears about divine fatherhood, and David Fergusson has a well documented article on 20^th century debate about the salvation of those who don't believe in the Trinity. Ellen Charry, starting with an exposition of Justin's Dialogue with Trypho charts the history of polemics between Jews and Christians and suggests that it would be fairer for Christians to begin dialogue with the Jews on the common ground of one God. Gavin D'Costa contains an interested assessment of the ideas of Dupuis and Pannikar and maintains that the theological problems of those who don't believe in the Trinity are best helped by the doctrine of the Trinity.

Inevitably, some of the articles, which have to be compressed for reasons of space in a handbook of this kind, do not make easy reading. If I were to name three articles for their overall quality of theological discussion in lucid prose, they would be the articles by Kathryn Tanner, Marshall and Francesca Murphy. The two writers who most made me want to read the authors they discuss were Ayres on Augustine and Aidan Nichols on Scheeben. Not least of the merits of this book are the bibliographies (post 1990) at the end of each chapter, which should save time for students and lecturers alike. The editors are to be highly commended for master-minding this handbook, which could well set the pattern for the teaching of the Trinity in the future.