Belief systems nurtured by brain cells

The material in The Sacred Neuron began life as the 2003 Henson lectures at Oxford, required by the terms of the bequest to address "the appeal to history as an integral part of Christian apologetics". John Bowker gave his series the overall title "Did Henson waste his money?" and used the lectures to explore how people justify their beliefs in a range of different areas of life, what warrants they offered for their assertions, and whether they were adequate.

The book's central chapters reflect its origins, considering first the appeal to history, but moving swiftly to other possible grounds for truth claims: appeals to value (first in art, then in ethics) and finally to coherence. This last is a key concern. All religions, says the author, operate on the basis of a coherence theory of truth, and they have no option but to do so. The alternative correspondence theory requires for its justification empirical evidence of a kind simply not available to most religious claims. After all, Bowker says, neither Christians nor Buddhists can produce God or the Buddha as objects among other objects in the universe.

The book is in essence a defence of coherence theories against well-known problems they face. The argument presented takes the following form. First, they are not, in fact, theories of truth but of epistemic justification (how claims to knowledge are supported). Second, what distinguishes all coherence theories from correspondence theory is their insistence on the possibility of error in what we "know" about the world. Third, the naive realism associated with correspondence must therefore give way to a form of critical realism. Finally, we cannot justify any theory simply on the grounds that it shows inner coherence, because "our judgments are constrained by facts which are independent of our opinions".

These independent facts are known as conducive properties, and they are central to Bowker's attempt to steer a middle course between naive realism and a free-wheeling relativism. They are not coercive - since not everyone finds the same things beautiful or good - but they do account for the high degree of unanimity among humans in certain emotional responses and rational judgments. So, for instance, philosophers who say that beauty itself is an inherent property of a circle are wrong, but there are in the circle conducive properties that lead to a common emotional response, and that includes a satisfying sense of beauty.

This is the point where neurons (brain cells) come in, because, according to Bowker, it is something in the make-up of the human brain that responds to conducive properties in nature and results in culture-independent human experiences and responses. Where these involve religion, he claims, the integration of reason and emotion is fundamental.

Bowker has a distinguished record as an author and editor, but this volume is disappointing. The contents have little to do with its title, which leads one to expect a discussion of the discipline of "neurotheology" - studying the neural correlates of religious experience. Yet neuroscience occupies only a few pages. Also, the writing has too many anecdotal asides and lacks a clear focus.

The author admits in his preface that only generous grants from the Templeton Foundation made publication possible. Its agenda probably accounts for the misleading title, and the implied unwillingness of the publishers to finance the project themselves suggests I am not alone in regarding The Sacred Neuron as below the standard of Bowker's best work.

Revd Anthony Freeman is managing editor, Journal of Consciousness Studies.