This book argues that religious experiences share a common, underlying structure and defends the view that at least some of them are veridical. Its more specific aim is to show that recent developments in neuroscience should not lead us to conclude that all religious experiences are illusory.

The book is divided into three parts. Part 1 offers an account of the nature of religious experience and proposes a criterion for identifying genuine religious experiences. According to Hick, religious experience is the ‘living heart of religion’ (37) and can be distinguished from ‘religion as institution and communal practice’ (13). Although religious experiences are conceptualized in a wide range of ways by different cultures and religions, he thinks that they share a common core, consisting of communion with the Transcendent or Ultimate, and thus of the realization that there is more to reality than the mundane world that empirical science describes. Hick adopts a permissive conception of religious experience, acknowledging that apprehension of the Transcendent need not be conceptualized in an explicitly religious way:

He goes on to argue that genuine religious experiences can be identified by the moral and spiritual fruits that they yield (51).

Hick's account of religious experience is very much like that of William James. In The Varieties of Religious Experience, James similarly stresses the primacy of religious experiences over religious institutions, claims that there is an underlying core to be found beneath historically and culturally diverse descriptions of religious experiences, and offers a pragmatic argument for the view that some religious experiences are veridical. Hick thus faces many of the same objections that have been raised against James. For instance, it is not clear that religious experience can be fully disentangled from the many heterogeneous ways in which it is conceptualized. In addition, the claim that religious experience is wholly distinct from and more fundamental to religious belief than religious practices and institutions is contentious. Culturally contingent practices are arguably not just interpretive frameworks in terms of which pre-given religious experiences are understood; it may well be that some kinds of experience are only possible in the context of specific kinds of practice. Furthermore, whether or not an experience ‘bears fruit’ depends in part on the culture in which it is embedded. For example, if the experience is dismissed by a person's contemporaries, who alienate or persecute her for it, the fruits are likely to be less than in a more receptive culture. And, of course, the judgement as to whether or not something has borne fruit will most likely be shaped by the contingent values of the assessor. Hence the ‘universal criterion of the authenticity of religious experience’ which ‘consists of its moral and spiritual fruits in human life’ (51) is surely vulnerable to a range of cultural contaminants.

However, if we accept that many or all religious experiences do share much the same underlying sense of the Transcendent, the question arises as to whether or not the core experience is veridical. Hick's concern in Part 2 of the book is to defend the view that some religious experiences are indeed veridical against the threat of scientific naturalism and recent work in neurobiology. He makes the plausible claim that the ‘naturalistic world-view’ consists of a kind of ‘faith’ (55–56), rather than being a doctrine that is founded upon rational deliberation and empirical evidence. Amongst other things, this faith amounts to a refusal to even entertain the possibility of veridical religious experience. It also motivates the project of explaining religious experience in terms of brain pathology.

Hick goes on to discuss some recent neurobiological studies of religious experience, carried out by V. S. Ramachandran, Andrew Newberg and Eugene d'Aquili, Michael Persinger, and others. In so doing, he challenges the apparent implication of some studies that the relevant experiences are ‘products of local brain malfunctions’, which arise due to epileptic seizures, psychotropic drugs, or a variety of other causes (63). Hick points out that: ‘a blow to the head can make you see stars which are not physically there, and various drugs can induce much more complex hallucinations, but this does not show that there is no physical world that can also be perceived more or less correctly’ (74). Likewise, the fact that certain so-called ‘religious’ experiences might be hallucinations does not imply that they all are. He notes that what Ramachandran refers to as a ‘religious experience’ that sometimes occurs during temporal lobe seizures is quite different from the kind of experience reported by Tibetan monks, the subjects of a different study. Whereas occurrence of an experience during seizures might suggest that it is pathological and thus unreliable, no such conclusion can be drawn from neurobiological studies of meditating monks. A genuine religious experience should thus be distinguished from a pathological experience that is conceptualized in religious terms. There are, according to Hick, insufficient grounds for suggesting that religious experiences in general are pathological or that the people who have them are any more prone to psychiatric complaints than the general population.

Hick is, I think, right to draw a distinction between religious experiences and certain pathological experiences that are superficially similar. However, perhaps he sacrifices too much by going along with the assumption that ‘religious’ experiences occurring in the context of brain pathology are unreliable. As James recognizes in the first lecture of Varieties, brain pathology and veridical experience need not be mutually exclusive. More generally, it is possible to gain numerous genuine insights from the experience of illness. Consider Tolstoy's Ivan Ilych, lying on his deathbed and finally realizing that he has wasted his life by losing himself in frivolous social statuses and performances. His insight is surely not to be dismissed on the basis that it has arisen due to alterations in experience and thought that are associated with pathology. Could the same point not apply to certain pathologies of the brain?

Hick goes on to address the commitment to naturalism that often operates as a backdrop to the interpretation of scientific studies. He distinguishes two variants of naturalism – materialism about the mind and epiphenomenalism – and proceeds to dismiss them both. The argument in this part of the book is weak. Rather than offering a detailed and sufficiently persuasive case against naturalism, Hick appeals to a series of familiar arguments that one might find in an introductory philosophy of mind textbook. These arguments will not convince anybody who is not already convinced. Hence, at best, he manages to achieve a stalemate with his naturalist opponent. Much of the discussion is too cursory to do any philosophical work. For example, only two and a half pages are dedicated to the topic of ‘consciousness and evolution’, where Hick speculates as to which allegedly ‘moral’ behaviours might be explicable in evolutionary terms. He then asserts, without any supporting argument, that it ‘would take complex epicycles of speculation to avoid the powerful reality of self-transcending values that exist for humans only in virtue of our consciousness’ (99).

In place of materialism and epiphenomenalism, Hick endorses a form of substance dualism, which is distinguished from that of Descartes only by Hick's rejection of the views that interaction takes place via the pineal gland and that non-human animals are mindless (111). Having chastised materialists for resorting to vague metaphors at crucial points in their arguments, Hick offers the following analogical description of mind-brain interaction: ‘The relationship between consciousness and the brain seems to be like that between two dancing partners who always move together but sometimes with one and sometimes the other taking the lead’ (106). His dualist position is not developed any further and, when it comes to the question of how interaction might occur, he offers just this: ‘We can only say that it happens in accordance with natural law’ (111). However, we do not currently know of any natural laws regulating dualistic mind–brain interaction. Furthermore, it is not clear how such a law could ever be discovered, how it might relate to the natural laws that we do know about, or even whether the concept of a natural law involving interaction between material and immaterial substances is a coherent one. Hence more is surely needed here.

Once Hick has dismissed naturalism in its materialist and epiphenomenalist guises, I was left wondering why he felt the need to discuss recent findings in neurobiology at all. He states that the neuroscientific challenge ‘presupposes either mind/brain identity or epiphenomalism’ (80). So it is not clear why he thinks that the scientific findings he discusses pose a problem for religious experience, once they are extricated from the context of naturalism. As already noted, Hick assumes that certain ‘malfunction’ explanations are in tension with there being genuine religious experience but it is not clear that this is actually so and, even if it is, most of the research that he discusses does not explicitly endorse malfunction explanations anyway.

Rather than a cursory discussion of recent science, accompanied by some less recent arguments against naturalism, Hick might have offered a detailed philosophical study of the neuroscience (which, as the title of the book indicates, is supposed to be the primary focus) and addressed in depth a wide range of relevant and interesting philosophical questions. For example, ‘Is the science in question good science?’; ‘If not, why not?’; ‘What methodological and conceptual problems do studies of specifically “religious” experiences encounter?’; ‘What, if anything, does the neuroscience actually show, once it has been extricated from any naturalistic underpinnings?’; ‘Are any genuinely new philosophical issues raised by recent work on the neurobiology of religious experience?’; ‘Could the science be interpreted so as to cohere with or even support Hick's own view?’; ‘Can one sustain a genuinely agnostic standpoint when pursuing such research?’; ‘Should one?’; ‘Does neurobiology have any role to play in arbitrating between naturalistic and non-naturalistic conceptions of the world?’; ‘If so, which way do the findings to date point?’; ‘Are there some aspects of experience that are irrevocably inaccessible to empirical scientific research and, if so, why?’.

When Hick addresses Benjamin Libet's work on the neurobiology of free will, the discussion improves somewhat. Hick argues that determinism, even in the guise of an explicit ‘compatibilism’, incorporates an implicit self-contradiction. We can only think of ourselves as rational beings if we assume that we are free. Hence, even if we are not free, we could not coherently believe it because we could not assent to the belief without implying at the same time that the belief in question should not be trusted:

Things improve still further in Part 3, where Hick offers a good general case for veridical religious experience, suggesting that we should adopt the same attitude of ‘critical trust’ towards it that we adopt more generally (130). He goes on to advocate a plausible form of religious pluralism, based loosely upon Kant's distinction between appearances and things-in-themselves. There is, Hick says, an ‘inbuilt human capacity to be aware of the universal presence of the Transcendent’, which is ‘always manifested in particular culturally and historically conditioned ways’ (164). This final part of the book is better argued and more convincing than Part 2. Hick thus succeeds in sketching a case for veridical religious experience that is philosophically respectable overall, even though the discussion of naturalism and neuroscience is lacking.

The book is clearly written and engaging throughout. It will be accessible to undergraduate students and to general readers with an interest in science and religion. However, it will be of limited use to researchers who are already well versed in these debates, and it will not convert any scientific naturalists.