If you are a famous atheist in Britain today, you probably explain the phenomenon of theism solely in terms of ‘imagination’. God is an illusion, or delusion, something believers ‘make up’, like a lying child. In debates, you can belittle believers in God by telling them that they have ‘an imaginary friend’. And you are sure that this is where the moral evil of theism resides: like children, believers are not willing to admit to their over-active imagination. They stick to their lie; and religious violence is always, at the root, a strop about being found out. So, with more relish than regret, you have to upgrade Occam's Razor to a combine-harvester, getting rid of not just unnecessary explanation, but all of what Mr Gradgrind calls ‘fancy’. You might quote your departed friend, Douglas Adams: ‘Isn't it enough to see that a garden is beautiful without having to believe that there are fairies at the bottom of it too?’ And if God is a fairy-tale, why not put all theology in that section of the library? A.C. Grayling once listed a number of beings in the same category as God: Little Red Riding Hood, Rumpelstiltskin, Santa Claus, Betty Boop, Saint Veronica (who ‘allegedly started out as sweat on a cloth and became a person’), Aphrodite, Wotan, Batman…

One course of defence theologians might usefully adopt would be to say (very quietly) that yes, the imagination is what tells us about God; and what it tells us is true. This is Douglas Hedley's position in this book: ‘neither the inspired symbols of revelation nor the great conjectures about God are mere fantasies, since the imagination of the human soul mirrors, however darkly, the fecundity of the divine mind’ (p.  8). As that quotation suggests, this is an up-front and unashamed contemporary version of the sort of Platonism that inspired John Smith, Henry More and Ralph Cudworth. It could hardly be more unfashionable if it tried. When Richard Dawkins is openly attacked, Hedley's champion against him is Benjamin Jowett (p.  44).

But then Hedley is not really defending the God that Dawkins, Grayling and others attack. He is defending something even more unfashionable: the concept of imagination itself; and in this sense, the defence is as much Romantic as it is Platonist. The Prelude is as important as the Phaedrus: Wordsworth's definitions in the Prelude of imagination as ‘clearest insight’, ‘amplitude of mind’ and ‘Reason in her exalted mood’ guide Hedley's thinking throughout. He argues that imagination is natural to the human being; that it is essentially creative, part of what William James calls the ‘exuberant excess’ of human capability; that it plays a part in any proper understanding of what it is to be human; that the imagination acting ethically unites us with the Divine –‘conscience is the candle of the Lord’ (Butler); that this combination of creativity and ethics helps us to think of symbols and tell stories that are not necessarily to be described in narrow terms as ‘fiction’; in fact, such symbols and stories are ‘tautegorical’ (a term he takes from Schelling and Coleridge) and, unlike allegorical symbols, do not have  to be boiled down. They can lead to substantive knowledge; among other things, to knowledge of God and the good.

With this concept of the imagination to hand, Hedley revisits areas of theological enquiry: metaphysics, psychology, ethics, aesthetics, mysticism, apocalyptic and the atonement. At all times, Hedley is keen to assert the irreducibility of imagination, against the oversimplifications of modern reductive science. However, the difficulty in correcting an oversimplification is how to correct it simply; how to avoid embodying the complexity one wishes to uphold. This is a pitfall familiar to those who read Rowan Williams’ work; and Hedley does not always avoid it. His bewildering range of reference can sometimes overwhelm the line of argument; and for someone with plenty to say about storytelling, the glaring weakness of this volume is its lack of a coherent narrative. There seems almost a reluctance to jettison research and example in favour of summary and elucidation.

Take, for example, chapter 7. This is entitled ‘Inspired Images, Angels, and the Imaginal World’, and purports to deal with ‘special revelation’. Following Austin Farrer, Hedley says he will develop a concept of revelation through images that, unlike ‘Barthianism’, will depend ‘less upon the verbal articulation of its revelation than it does upon its iconic structure.’ In the very next sentence we are told that Hölderlin's ‘Patmos’ will be used as a departure (presumably alongside Austin Farrer). The sentence after that reminds us that Hölderlin was a lyric poet shaped by the tradition that runs from Milton to Klopstock. Then we have a quotation from Milton; one from Marx; a reference to Ovid; and then Wordsworth and Goethe are brought in. Then we are wrenched back to Hölderlin. Then we reference Wallace Stevens, Rilke and Klee, before the section ends. The next section begins with the apparent non sequitur ‘In Proust's À la recherche…’ and quotes from Proust in French without translation. The reader waits and waits for more explication of the ‘iconic structure’ of revelation. Any three pages in the book could have been described as I have described these three (pp.  211–213). Of course, this is not an unusual level of difficulty in reading a work of contemporary theology. But it seems to me unnecessary difficulty. Some blame lies with the publishers, whose readers have not served Hedley well. And section headings within chapters seem to have been imposed by an editor; at times they interrupt and actually obscure Hedley's argument (e.g. p.  20).

This is unfortunate, because any student would learn so much from this book. Taking a lead from Charles Taylor, Hedley has plenty to say about the limits of analytic philosophy (though I wished he had taken note of Mary Midgley's ‘Science and Poetry’). It does seem odd that philosophy undergraduates may still limit their discussion of imagination to considering the statement ‘The King of France is bald’ (p.  176). But the book has theological as much as philosophical or scientific targets for rebuttal. The reductive modernist theology influenced by Bultmann was a lifeless dead-end because Bultmann underestimated the imagination: ‘the mythic dimension of Christianity was less of an obstacle than Bultmann supposed’ (p.  126). Hedley presents telling readings from those masters of the fairy-story, J.R.R. Tolkien and C.S. Lewis, and agrees with Lewis: ‘If God chooses to be mythopoeic – and is not the sky itself a myth? – shall we refuse to be mythopoeic?’ (a quotation from the essay ‘Myth Became Fact’).

Some may ask whether Hedley takes seriously enough the challenge that runs down from Xenophanes to Feuerbach: are we forming gods in our own likeness? Hedley's line of argument says that what we do by inhabiting the Christian imaginary is discover truths about ourselves, rather than project untruths onto reality. But how do we know for sure that this is the case? We might reply that we cannot know for sure; the real illusion is the idea of sure knowledge outside any sort of imaginary. The problem for Hedley here is not that he cannot deal with the projectionist hypothesis; but that the force of the arguments he rejects is greater than the force of his own argument. As with brains in vats and other epistemological problems, eventually one comes not to a solution, but to a provisional position; and the provisional position of entering by faith into the religious imaginary is not likely universally to satisfy. What Hedley is arguing against – the dismissal of religion as fiction – is about as sophisticated as Samuel Johnson dismissing idealism by kicking a stone. But plenty of scientists and philosophers are passionate stone-kickers when it comes to religion. And increasingly, so are educated men and women outside the academy. What Hedley prescribes is a vast Bodleian of resources that will allow us to enter the world of faith. But is it only the erudite who inherit the kingdom? And if not, why should anyone bother? Surely the next project for Hedley should be an exploration of ‘sin’. Much here is about the elevating aspects of faith: the notion of ascent to the divine, as found in Plato and Wordsworth. Much more universal, it seems to me, is the imaginative apprehension of the descent into hell – recorded by atheist and believer alike.

Nevertheless, this book is a triumph of against-the-grain ingenuity and scholarship. Hedley deserves our thanks for refusing to accept the scything reductionism of his philosophical contemporaries with their accusations of ‘imaginary friends’. Instead, he opens up new fields of enquiry, which theologians of all sorts would do well to enter.