One welcome legacy of the New Atheism as a social phenomenon has been the surfeit of elegant and sophisticated defences of religious belief it has elicited over the last decade or so. Crudely, the responses among philosophical theologians fall into two categories. The first sort of response engages specific objections to theistic belief and typically does so in an analytic key. The second, by contrast, rejects the very terms of the debate by refusing to recognize the conception of God that sceptics have in their sights: on this latter view, responses in the first category conspire with sceptics in an unseemly modernist parlour-game that bears no resemblance to the divine reality towards which religious believers seek to orient their lives.

It is to the credit of this book that it makes a serious attempt to rehearse the case for each of these two disparate stances, even if they prove eventually to be irreconcilable. Chapters 1 and 2 imply that the sympathies of the author lie in part with the second approach. The titular declaration that God is no ‘thing’ is intended to remind the reader that God is not an ordinary object of human inquiry. One could be forgiven for thinking that this claim does not amount to more than the platitude that God is not a created thing. And yet one must also accept that the history of Abrahamic monotheism testifies to the immense difficulty of thinking and talking about the divine in ways that accommodate this basic truth. The function of the claim is, in effect, to resist the tempting but allegedly idolatrous allure of natural theology; on this view, the apophatic reflex is a tool, as Nicholas Lash once put it, for ‘checking our propensity to go whoring after false gods’.

Perhaps it is right that natural theology can achieve no more than a rational belief that God exists. But that is no small gain; and it is also one that coheres perfectly well with insisting that God exceeds the limits of our capacities to fathom him fully. It is refreshing, then, to find that Rupert Shortt does not marginalize the role of natural theology in his reflective inquiry into religious belief and the religious life. He devotes chapter 3 to a useful taxonomy of how some philosophical arguments can underwrite a theological picture of reality. Some may regret that the book's philosophical centrepiece dwells so much on the Five Ways, since this has the effect of excluding many lively contemporary debates among philosophers of religion that Aquinas does not address (the Five Ways are, after all, formulated with a degree of compression bordering on the casual – roughly the length of an undergraduate assignment, the relevant passages make up less than one-tenth of one per cent of the Summa). Still, the discussion is accessible to the general reader and consistently lucid. It is difficult to share Shortt's view that the First Way is considered to be the strongest of the five arguments Aquinas presents: given its alleged tensions with Newton's first law of motion, it may indeed be the most contentious. And, once or twice, Aquinas's argument from contingent things is conflated with Leibniz's argument from contingent facts. It is not quite right to say that the reason why Aquinas thinks God exists as a necessary being is that the existence of contingent things would otherwise be ‘inexplicable’ – this would be closer to Leibniz's preference for the principle of sufficient reason over the principle of causality. Aquinas reaches the conclusion he does because he denies there could be an essentially ordered infinite series of necessary beings.

The focus on Aquinas also unwittingly forecloses theistic positions that reject Thomist and/or Aristotelian metaphysical starting points. Arguments for God's existence are unlikely to succeed if they depend too much on a metaphysical hinterland that one's interlocutors have independent reasons for rejecting. Still, many philosophers of religion will find rejoinders to religious scepticism that appeal to Thomist and Aristotelian metaphysics preferable to older Kantian strategies such as John Hick's quest for the ‘Real’ in the 1970s or Don Cupitt's atheological ‘non-realism’ in the 1980s.

If the author is a little incautious to place all his apologetic eggs in one metaphysical basket, it should be noted in his defence that there has been a remarkable renewal of interest and confidence in Aristotelian themes among analytic philosophers that span the nature of causation, properties, kinds, essence, and modality. Defenders of Humean orthodoxy can no longer dismiss this renaissance as an irrelevance (a similar story can be told of the contemporary history of moral philosophy, whose indebtedness to Aristotelian ethics goes back at least as far as the 1950s). So the theoretical assumptions on which Shortt relies would be more acceptable to secular palates than they used to be.

The final stages of the book exhibit much of the theological acuity that characterized Shortt's conversations with leading theologians in God's Advocates (2005). His reflections and insights on the wider cultural context of the intellectual battles over belief are likely to provoke especially rewarding discussion. In contrast to some other responses to religious scepticism, his book does not shirk the importance of grounding a religious world-view in a coherent theoretical framework, even if that framework cuts sharply against the metaphysical mainstream, and even if its author treats the philosophical case for Christianity as a ladder to be discarded once the experience of faith begins.