In the introduction, McCall and Rea introduce the coherence problem. They write: “What theologians sometimes refer to as the ‘threeness-oneness problem of the Trinity,’ and what philosophers call the ‘logical problem of the Trinity” is well-known.” Fundamentally, it boils down to an apparent inconsistency between the central claims that constitute the doctrine of the Trinity, namely:
(1) The Father, the Son, and the Holy Spirit are distinct
(2) The Father is God, the Son is God, and the Holy Spirit is God
(3) There is only one God
A little reflection on these three propositions quickly arouses the intuition that they cannot all be true. But if that is the case, the orthodox doctrine of the Trinity is not only false, it is necessarily false, i.e. impossible. But of course, many Christians are convinced on independent grounds that it is true, and so the issue becomes, how can these apparently inconsistent claims be reconciled? PTET features several attempts to answer this question.
PTET is divided into four sections, the first three of which are each devoted to a general strategy for modeling the Trinity: Social Trinitarianism, Latin Trinitarianism, and Relative Trinitarianism. The first two of these approaches claim historical precedent, though the historical details are controversial (Richard Cross’s essay in this volume, for example, attests to that fact). But whatever one makes of the history of the Social/Latin Trinitarian divide, these two approaches as they are presently defended may be instructively contrasted with one another. Views which are typically classified as “social” models begin by emphasizing the diversity of the divine persons, and then attempt to account for their unity. So-called “Latin” models, on the other hand, begin by emphasizing the unity of God, and then attempt to distinguish the divine persons within this “pre-established” unity. While social models risk flirting with tritheism, Latin models must tread carefully so as to successfully skirt modalism. Meanwhile, Relative Trinitarian models seek a more metaphysically radical via media between the social and Latin approaches.
In part I, “Social Trinitarianism and Its Discontents,” both defenders and critics of the social strategy have their say. This part includes essays from Richard Swinburne, William Hasker, Brian Leftow, William Lane Craig, Daniel Howard-Snyder, Carl Mosser, and Keith Yandell. Some of the essays directly interact with each other, while others stand on their own. Although social models of the Trinity have much in common, such as the claim that each of the three divine persons is a distinct center of consciousness, these essays include discussion of several clearly different social models, showing the variety of options available even within the social point of view. Part II, “Latin Trinitarianism” is a bit disappointing by contrast, as it contains only two essays: one by Brian Leftow explicating his Latin model in which God lives his life in three distinct streams simultaneously, and a paper by Richard Cross which argues that, while Latin Trinitarianism is deeply rooted in the tradition, “Social Trinitarianism is a genuinely modern innovation.”
In part III, “Relative Trinitarianism: Prospects and Problems,” attention is focused primarily on two attempts to reply to the incoherence charge: Peter Van Inwagen’s relative identity solution, and Michael Rea and Jeffrey Brower’s model inspired by an Aristotelian solution to the problem of material constitution. The Rea-Brower proposal suggests that the divine persons exhibit “numerical sameness without identity” just as a statue and the lump of clay from which it is formed also (or so they argue) exhibit numerical sameness without identity. Both the Van Inwagen and the Rea-Brower proposal are presented, defended, and subjected to critique in part III, with two contributors (Christopher Hughes and Alexander Pruss) proposing modified versions of the Rea-Brower model.
The final section of PTET includes two essays (by Alan Padgett and Thomas McCall) calling for more interaction between philosophers and theologians on matters such as the doctrine of the Trinity. A number of issues are raised in this section, but one which is particularly worthy of note, given the nature of most of the essays in the book, is the role of mystery in theology. Are analytic philosophers who probe into the details of Trinitarian metaphysics treading in places they shouldn’t be treading, trying to solve problems that should be left unsolved? Here a comment at the end of Christopher Hughes’ chapter is helpful:
…I think that someone attempting to counter the anti-Trinitarian argument should distinguish between the project of giving us an understanding of why that argument does not work, and the project of giving us an understanding of how the doctrine of the Trinity can be true. Even if the first project is feasible in statu viatoris, the same may not be true of the second. As I see it, it is actually an advantage of [my proposal] that (unlike, say, the Swinburnean counter) it invokes a (very, though not entirely) mysterious relation…For the doctrine of the Trinity is mysterious, and the heart of the mystery is that each divine person is, in a way (or in a sense of “is”) that is beyond our power to understand, God.So it is not clear that an attempt to answer the charge of incoherence will necessarily be an attempt to banish all mystery from the Trinity, since it may be possible to model the Trinity in a way that is both logically consistent yet still mysterious or beyond our ability to fully grasp in certain ways. Another way in which such mystery can be preserved is to think of Trinitarian models as mere models which show that the central claims of Trinitarian orthodoxy can all be true simultaneously, even if the models which demonstrate this are not presented as actually representing God’s own being. To borrow some terminology from discussions of the problem of evil, we may think of Trinitarian models as “defenses” rather than “theodicies.”
In light of the esoteric and technical nature of many of PTET’s essays, another point that comes up in the final section of the book is worth noting. In the closing essay, Thomas McCall observes that the issues which take center-stage in this volume have pastoral relevance.
Perhaps it was only the rural Michiganders and rustic Alaskans I have had the privilege of serving as pastor, but I recall exactly no one who ever found themselves concerned about “ontotheology” or who were edified by “a theology of absence—where the name is given as having no name, as not giving the essence, and having nothing but this absence to make manifest.” I was, on the other hand, regularly surrounded by people who believed—very deeply and sometimes very fiercely—that the truly human Jesus was somehow also fully divine and one with his Father, that his life, death, and resurrection were somehow deeply meaningful because of who he was, and that somehow his Spirit was present with them today. They believed it to be true, and they believed that it mattered, and I saw many of them hold fast to this conviction at times of greatest hope and joy as well as at times of deeper disappointment and sorrow. They were also at points aware of challenges to their faith; on occasion they too were made to wonder if this luminous, beautiful doctrine at the very core of the Christian faith was perhaps necessarily false. Although they articulated them very differently, they believed that the issues addressed in this volume matter. They cared about the same issues that give rise to the problems addressed here. They cared about the truthfulness and meaningfulness of the central claims of the Christian faith—the same claims addressed in these essays. They knew that these things matter. And if analytic theologians remember this as well, their work may be of benefit to such people.
A few evaluative comments are in order. Overall this book does a fairly good job representing the different analytic approaches to modeling the Trinity, as well as including some of the most insightful critiques of each. However, the section on Latin Trinitarianism was disappointingly brief, especially considering that throughout the entire book there was (as far as this reviewer could tell) very little critique or engagement with Brian Leftow’s model. Also, something that would greatly increase the utility of this book is an extensive bibliography, cataloguing the important literature on this subject beyond those essays that were printed or reprinted in this volume. Granted, a lot of additional literature is cited in the footnotes of the various papers, but a single bibliography at the back of the book, perhaps, would be far more expedient. Altogether, PTET is an excellent book of quality papers, grappling seriously with an important and difficult problem. For apologists interested in defending the coherence of Trinitarianism with philosophical rigor, and for anyone else interested in philosophical theology or the intersection of analytic philosophy and Christian theology, this book is highly recommended.
Apologetics 315 Book Reviewer Justin Mooney is a graduate student from Michigan. He has a degree in art and design, and he is currently studying philosophy of religion. He plans to become a professor.
 Cross, Richard. “Latin Trinitarianism: Some Conceptual and Historical Considerations.” In Thomas McCall and Michael C. Rea (eds) Philosophical and Theological Essays on the Trinity. New York, NY: Oxford University Press 2009 p. 213
 Hughes, Christopher. “Defending the Consistency of the Doctrine of the Trinity.” In Thomas McCall and Michael C. Rea (eds) Philosophical and Theological Essays on the Trinity. New York, NY: Oxford University Press 2009 p. 313 emphasis in original.
 McCall, Thomas. “Theologians, Philosophers, and the Doctrine of the Trinity.” In Thomas McCall and Michael C. Rea (eds) Philosophical and Theological Essays on the Trinity. New York, NY: Oxford University Press 2009 p. 348