William Hasker offers the first book-length examination of the doctrine of the Trinity from the perspective of the emerging field of ‘analytic theology’. Analytic theology uses the tools and methods of analytic philosophy in the service of constructive Christian theology. Hasker aims to construct and defend a broadly orthodox, philosophically coherent account of the Trinity which answers the logical question: how can there be three divine persons but only one God?
Hasker is a ‘social trinitarian’ and so he defends an account of the Trinity on which the Father, Son and Spirit are ‘distinct centers of knowledge, will, love, and action’ as well as ‘distinct centers of consciousness’ (p. 22). Put another way, the three persons are also three distinct divine agents. When they act together, they act in concert (and necessarily so, according to Hasker), but their actions remain numerically distinct. The challenge for social trinitarians is to avoid tri-theism. Prima facie, it is difficult to see how the three persons, so construed, nevertheless count as a single God.
Hasker does not just assume social-trinitarianism, but argues that it is the best way to make sense of the scriptural data and the witness of the patristic fathers. Indeed, he spends ten chapters, roughly one-third of the book, discussing the scriptural and patristic foundations of the doctrine of the Trinity. He engages with both primary sources (Gregory of Nyssa and Augustine) and contemporary scholarship (Lewis Ayres figures prominently). Throughout this section, Hasker shows a noteworthy deference to the patristic tradition and to creedal orthodoxy, even as he also recognises that ‘if we are to have a visible and coherent trinitarianism for our own time, we need to do better . . . than [our patristic forebears] were able to do’ (p. 77). To that end, in the next section, he surveys four theologians (Barth, Rahner, Moltmann and Zizioulas) and seven analytic philosophers who have offered contemporary accounts of the Trinity, before turning to his own constructive account in the final section.
Hasker argues that the three divine persons each instantiate a single, numerically identical, concrete divine nature – in analytic parlance, ‘a single trope of deity’ (p. 236). Having previously defended the doctrine of the divine processions and the eternal generation of the Son and procession of the spirit, Hasker is able to say that the Father communicates the single divine nature to the Son and Spirit. Similarly, he defends an understanding of perichoresis on which the Father, Son and Spirit necessarily act in complete unity and harmony. So the fact that the three persons are constituted by a single divine nature and necessarily act in harmony is what ultimately guarantees that the three persons are one God and not three.
Hasker appeals to the metaphysics of constitution as the best philosophical framework in which to understand these traditional doctrinal claims. Matters get technical here, and I lack the space to lay out Hasker's account even in abbreviated form. But the basic idea is that the single divine nature constitutes the three persons. Constitution does not entail identity, and so the divine nature is not identical to any of the three persons, nor are any of them identical to each other, yet they are one insofar as they are constituted by the same trope of deity. A remote analogy: a piece of cloth, for example, can constitute a flag without being identical to the flag (since we could destroy the flag by bleaching it without destroying the cloth).
While there has been a major resurgence of trinitarian thought in contemporary theology, theologians seldom address basic questions about the doctrine's underlying coherence. The Christian church (broadly construed) has traditionally regarded the doctrine of the Trinity as the height of mystery, to be sure, but not as an absurdity or a bare contradiction. It seems to me that theologians therefore ought to welcome Hasker's book, and his attempt to defend the coherence of the most fundamental tenet of the faith.
