There is currently a considerable resurgence of interest in the debate between science and religion. This is evident in the writings of both “creation scientists” and “new age” enthusiasts. But despite their substantial public following, neither group is part of the serious academic debate, because they do not give sufficiently earnest attention to scientific issues.

There are, however, two main camps that do take science seriously. On one side are some dogmatic atheistic scientists and philosophers, who show great rigidity and exhibit absolute certainty in their claims – even though these are of a metaphysical nature, way beyond the domain in which any degree of scientific certainty is attainable. On the other side is an increasing number of scientist-theologians and philosophers, who show a greater flexibility in their approach and a better understanding of the philosophical issues involved.

Prominent among the latter is John Polkinghorne – quantum physicist, fellow of the Royal Society, former president of Queen’s College, Cambridge, and an ordained Anglican priest. He has written prolifically in this area, and this book provides an intelligent and well written summary of some of his views. It covers three main areas. First, he presents a cautiously revised form of natural theology. Then he gives a methodological comparison of science and theology that exhibits their common concern in the search for truth. Finally, Polkinghorne speculates about how physical process might be sufficiently open to accommodate both human and divine agency. The book also contains some interesting speculations on the prospects for future dialogue between science and religion.

In the section on natural theology, the author considers signs of “mind” and “purpose” in the structure of the physical universe – first discussing the apparent rationality of the universe, before turning to the modern-day version of the “argument from design”. As one interpretation of the anthropic principle, this is based on the observation that only particular kinds of universes are capable of producing systems of sufficient complexity to sustain conscious life. The apparent conclusion is that this fine-tuning in our universe is evidence either that God is real, or that there are many and varied universes (although possibly both could be true).

Polkinghorne then examines and criticizes the various ways in which the multi-universe option on its own might hold. He believes that they either still require major fine-tuning, or are “far beyond anything that can be called genuinely scientific in their prodigal conjecture”. He proposes instead that the theological option – that God is real – provides an intellectually satisfying understanding of what would otherwise be unintelligible good fortune. However, he emphasizes that this line of argument does not necessarily prove God’s existence, but offers instead an insightful account of what is going on. This account does not aim to rival a scientific explanation, he says, but “aims to complement that explanation by setting it within a wider and more profound understanding”. The relationship of this view to issues of value is cogently discussed, the author concluding that “we live in a world which is the carrier of value at all levels of our meeting with it. Only a metaphysical account which is prepared to acknowledge that this is so can be considered at all adequate”.

The discussion in the next section on the similarities between scientific and theological method is based on seeing both as examples of “critical realism”. His approach takes evidence seriously and provides a rational middle way between certainty and relativism, proposing that science and theology aim to understand different aspects of reality using quite different kinds of data. The author also gives an interesting parallel analysis of the development of theories in science and theology. He argues that progress leads in each case to moments of new synthesis and understanding in which a new theory is revealed, but also to a continued wrestling with new unsolved problems.

In the author’s view, the most troubling issue in this view of science and theology as parallel ways of seeking truth is the great variety of religious faiths, as opposed to the much more unified view attained by science. However, he suggests that despite this variety, we can see the world’s religions as all seeking to speak of a shared encounter with spiritual reality. The impressive success of science in answering questions to universal satisfaction is seen to derive not from the possession of utterly distinctive methodology, but rather “from the comparative tractability of its subject material: an impersonal physical world open to experimental manipulation”. Polkinghorne points out that this is “in contrast to the more subtle realms of unrepeatable experience which correspond to personal encounter and to the transpersonal meeting with the divine”.

Perhaps the most controversial part of the book is the chapter entitled “Does God act in the physical world?”. This investigates what one can say about this question, while also taking seriously what science says about the regularity of processes in the physical world. Polkinghorne suggests a variety of approaches. For example, he invokes quantum uncertainty or suitable macroscopic processes as the enabling feature that could allow such action.

The suggestion that I find most problematic is that the sensitivity to initial conditions in chaotic dynamical systems might allow a causal principle enabling such action. Be that as it may, the author does indeed show that there are a variety of ways in which a God may be able to influence the detailed course of worldly events, even though that God voluntarily chooses – as an essential part of his action as creator – to maintain the laws of physics in unchanging form. The question of the nature of time comes in here in an essential and somewhat mysterious way, mirroring the mysterious nature of time in quantum cosmology.

This book presents a carefully thought out and well defended, if somewhat orthodox (Anglican) position. Apart from any engagement that they may have with the theological issues, there are two features of the discussion that may be interesting to practising scientists. The first is this view of theology as a rational, evidence-based discipline – in contrast to the view held (not without justification) by many of theology as a purely dogmatic subject. The other feature of the book is its reflection on the way that science is conducted in practice, as opposed to the idealized way scientific development is often presented.

Because we cannot each carry out all of the scientific experiments on which the present-day scientific world-view is based, science in fact proceeds to a considerable degree on the basis of faith in what is written in highly esteemed texts and taking on trust what is said by recognized authority figures. Furthermore, not all experimental data are taken seriously – one weighs the data against who carried out the observations and how well their results fit into current theory. And one’s choice of theory takes place to a significant extent on the basis of non-empirical factors. In other words, the distance from enlightened theological practice is not as great as some would like to suggest, and Polkinghorne’s book contains interesting comments making this case.