Anyone looking for a thorough, balanced, informative, well-written and accessible overview of twentieth-century trinitarian theology will want to read this book. In masterful fashion Stanley Grenz narrates the revival of trinitarian theology that took place in the eighty years that extended from Barth's Epistle to the Romans to T. F. Torrance's The Christian Doctrine of God which he describes as the ‘last comprehensive trinitarian theological offering of the century’ (p. 3).

By focusing on four major topical areas and analysing the thought of eleven prominent contemporary theologians in order to explicate those topics, Grenz divides his book as follows: (1) the eclipse of the doctrine and its renewal as this took place especially in the thinking of Barth and Rahner; (2) seeing the Trinity as the ‘Fullness of Divine History’ especially in the thinking of Moltmann, Pannenberg and Jenson who saw the identity of the triune God ‘as arising out of the interplay of the three trinitarian members within the flow of history’ (p. 5); (3) understanding the Trinity in terms of social trinitarianism and relational ontology in the thought of Boff, Zizioulas and LaCugna; and finally (4) considering what Grenz characterises as ‘The Return of the Immanent Trinity’ by focusing on the thought of Elizabeth Johnson, Hans Urs von Balthasar and T. F. Torrance.

Grenz begins by offering a brief and helpful history of the doctrine, including developments in East and West, and then explains how medieval speculation about the Trinity, by separating the Treatises on the One and Triune God and by divorcing trinitarian thinking from practical experience in the church, eventually led to the doctrine's demise. According to Grenz the doctrine came to be ‘eclipsed’ by thinking that focused on Christ's benefits instead of the unity and trinity of God himself and then by Unitarian and other Enlightenment-style thinking. Next, beginning with Schleiermacher and Hegel, Grenz shows how interest in the doctrine began to revive during the nineteenth century. Strangely, Grenz seems to side with those who would attempt to rehabilitate Schleiermacher's thinking as a worthy example of trinitarian theology today, even though he himself notes that for Schleiermacher the doctrine ‘is the product of the attempt to pull together various elements of Christian experience’ (p. 21) and that Schleiermacher ultimately may well be reducing theology to anthropology. Commencing with Hegel, one key theme that emerges and runs throughout this book as a kind of ‘golden thread’ structuring the discussion is the issue of the proper relationship between the immanent and economic Trinity. Should we, with Hegel, allow them to coincide completely so that history not only constitutes the eternal relations of the triune God but determines it, or should we, with T. F. Torrance, make a clear and sharp distinction in order to recognise and respect the divine freedom in se and ad extra?

In the end Grenz concludes that if a consensus now exists regarding this issue it is that ‘any truly helpful explication of the doctrine of the Trinity must give epistemological priority to the presence of the trinitarian members in the divine economy but reserve ontological primacy for the dynamic of their relationality within the triune life’ (p. 222). Still, he insists that there is a deeper metaphysical issue at stake here that concerns the kind of ontology needed to advance this understanding. For Grenz the solution to this issue lies in ‘an ontology that is thoroughly eschatological and communal’ (p. 222). This solution, however, begs the question in a certain sense because the history of the doctrine in the twentieth century shows, as Grenz very ably demonstrates, that not every eschatological and communal emphasis is always one that is faithful to the activity of the Holy Spirit who, as Grenz says, sparks in us new ways of imagining and articulating the Christian doctrine of God. The question, of course, is which of those new ways is actually grounded in the trinitarian self-revelation and which is not. One has only to think of Ted Peters's claim (relying in part on Moltmann and Pannenberg) that God will not be fully God in relationship until salvation history is complete, or Robert Jenson's claim that the economic Trinity will only be identical with the immanent Trinity eschatologically, with the result that Jesus will not be the eternal Logos until some time in the future. Or one might equally think of the relational ontology espoused by Catherine LaCugna, who concludes that ‘the doctrine of the Trinity is not ultimately a teaching about “God” but a teaching about God's life with us and our life with each other’ (p. 154) and ‘Trinitarian Life is also our life’ (p. 158), together with her mistaken belief that her work paralleled that of Colin Gunton who actually opposed equating trinitarian life with our life and collapsing the immanent Trinity into the economic Trinity in the manner suggested by her thinking.

Grenz makes every effort to present the positive and negative assessments of the many theologians he discusses. And therein one can see the strength and weakness of the book. Its strength is that the reader will be able to see all of the many sides of an issue with the help of Grenz's wide-ranging knowledge and clear, careful thinking and precise writing. Its weakness is that the reader might wish at times for a clearer indication of exactly where Grenz himself stands when it comes to some of the more controversial positions elaborated. For instance Grenz meticulously presents the thought of Elizabeth Johnson, claiming that her aim was to present faithfully a doctrine of the immanent Trinity. Yet Grenz also notes some key and debilitating weaknesses in her thinking, weaknesses that, in my view, would disqualify her approach as a relevant attempt to maintain a serious doctrine of the immanent Trinity. For someone such as Johnson, whose view of God's incomprehensibility is dictated more by her agnosticism than by the mystery of the Trinity, God is a symbol we use to create a better world, and the experience of women, she believes, should be the source and norm for theological reflection. Such thinking makes it difficult if not impossible to suppose that a doctrine of the immanent Trinity could function in any decisive way to point theologians to God's freedom in se and ad extra as the basis for human freedom. A proper doctrine of the immanent Trinity would point in exactly the opposite direction from the one proposed by Johnson because a serious recognition of God's freedom means knowing God's incomprehensibility does not mean that ‘God is like a Trinity’ (p. 181) as she contends, and it excludes the idea that experience could be the source and norm for theology and that we can use theological categories to achieve certain social or political results. While Balthasar and Torrance are excellent examples of theologians whose thinking illustrates a properly functioning doctrine of the immanent Trinity, Johnson clearly is not.

One final reservation concerns the notion that one might be able to distinguish the epistemological and ontological primacy of the immanent and economic Trinity in the manner suggested by Grenz. If it is truly the immanent Trinity that we meet in the economy, then would we not have to acknowledge that both the epistemological and ontological priorities are set by the economic Trinity precisely because it has pleased God who exists in eternal freedom and love as Father, Son and Spirit to create, reconcile and redeem the world? In other words by keeping epistemology and ontology together in a way that respects God's freedom in se and ad extra one would be less likely to search for an eschatological or communal ontology that is not inherently dictated by the self-revelation of the triune God in the history of Jesus Christ himself through the power of the Spirit. Any suggestion that the economic Trinity has epistemological priority while the immanent Trinity has ontological priority could lead directly back to the separation of the immanent and economic Trinity that Grenz himself opposes and that resulted in its eclipse in the first instance.

These questions aside, this is truly a splendid book written by a gifted theologian with a vast knowledge of contemporary trinitarian theology and a rare ability to communicate complex issues in a clear, understandable and indeed interesting way.