Originally the proceedings of a conference at Princeton Theological Seminary in June 2011, this volume aims at “an unofficial Catholic-Protestant dialogue” (subtitle) on the basis of a comparative study of Aquinas and Barth. The essays cover many of the standard but compelling topics between the two: the primacy of revelation and the unity of knowledge, Christocentrism and Trinitarian theocentricity, and the use of metaphysics in theology (White); the metaphysics of God (Robert Jenson, Richard Schenk); the appropriateness of predicating humility, obedience, and suffering of the eternal Son in the immanent Trinity and the rule for applying the communication of idioms (Guy Mansini, White); the relation between processions and missions (McCormack); the existence of natural revelation and the perspectives of creation and reconciliation (Keith Johnson); justification and the relation between nature and grace (Joseph Wawrykow, Amy Marga); the need for Christological mediation and the development of virtues in Christian ethics (John Bowlin); and the analogy of law as analogy of Christ (Holly Taylor Coolman).

The essays range from masterful and penetrating to insightful and substantial to solid and standard. Each essay seeks to elaborate both differences and similarities, as appropriate to a dialogue. In an ecumenical dialogue where we are often clear about the differences but not always about wherein they lie, I find the essays by White, Schenk, McCormack, Mansini, Wawrykow, and Bowlin quite impressive in the light they shed on the nature of the divisive issues. There are also frequent statements of what the dialogue is meant to achieve, not a hasty new synthesis, not a blurring of real differences, but a search for the fullness of truth through an “honest, profound, and charitable” (viii) interaction with “the doctrinal alterity of one another” (6). The discussion presupposes much knowledge of both Aquinas and Barth and makes the book appropriate only to graduate courses on Aquinas, Barth, or preferably ecumenical theology involving both. In the case of the latter it can be nicely complemented by another collection, The Analogy of Being: Invention of the Antichrist or the Wisdom of God? (2011), edited by one of the coeditors, Thomas White, OP, on an intimately related topic.

McCormack cites something central to the whole dialogue from Barth's letter to Eduard Thurneysen dated December 23, 1928. There Barth says that there is one thing Thomas did not know, even though he knew everything else; that on the basis of that one thing one must understand everything else differently, even those things one has no reason to oppose; and that one thing is that “man is a liar” (99)—a quintessentially Barthian remark, one might say. Even though many contributors point to many similarities and agreements in the volume, all these may have to be subjected to this proviso. It is a difference “truly fundamental” (100) and infects everything else, including seeming similarities, as McCormack rightly points out. My concern is that the contributors do a great job disclosing some of the differences between the two but perhaps not enough to engage those differences, to trace them to a more fundamental difference, and to argue for the greater adequacy of one side or another so as to really advance the dialogue. As things stand, the differences are nicely brought out, but not really engaged. Scholars will disagree about what constitutes the root difference between Aquinas and Barth, but isn't it precisely this fundamental difference that cries out to be engaged and argued? Some decades ago Otto Hermann Pesch pointed out that there is a fundamental difference in the very form of thinking (Denkform) between Aquinas (“sapiential”) and Luther (“existential”). Perhaps one can point to the difference in the very Denkform between Aquinas and Barth and go from there to argue about the relative adequacy of each form.

Despite this reservation I have no hesitation in highly recommending this collection for those interested in exploring the sharp differences between the two classical giants and exploring those differences further in a true ecumenical spirit to bring the two sides closer together.