From Noah to Newton

Successful bridges not only require firm supports at both ends; they also presuppose the existence of solid, albeit sometimes inaccessible ground between the two sides. Efforts at bridge-building between religion and science are dismissed by some scientists as being of no interest, because they can see nothing substantial to which the other end of the bridge might be attached, nor any common bedrock below the surface. Likewise there are religious believers who, as possessors of revealed truth, can see no relevance in science for a faith which floats free of other sources of knowledge, as a kind of Noah's ark for the enlightened few.

Fortunately there are others who believe that bridges are not only possible but necessary, if we are to avoid cultural schizophrenia. This volume of essays is an excellent illustration of what can actually be done. Its focus is on cognitive rather that practical issues, and it presupposes a bedrock of common concern for rational investigation of what the world is and what human beings are. It might have been better to call it "Christian Theology and Science" - since that is its subject - rather than religion in general, and my hope is that one day there will be a companion volume on interactions at the practical level. Nevertheless Mark Richardson and Wesley Wildman have given us a rich resource, and have demonstrated convincingly that constructive dialogue between theology and science is alive and well. The book is a must for serious students, and proves that, at least in the United States, such dialogue is on the way to becoming a proper academic specialisation in its own right.

Two sections, on history and method, are followed by a much longer one comprising six case studies, in each of which two or more authors have collaborated in preparing essays from different perspectives on cosmology, chaos theory, quantum complementarity, information theory, molecular biology and social genetics. The contributions by authors from different disciplines are unusually well related to one another, so there is a real sense of minds meeting and, if not agreeing, at least identifying where and why they diverge. The section devoted to method takes discussion further by means of a double round of contributions, and it is suggested that the validity of these should be checked against the case studies in part three. This inter-relationship between the parts makes the book ideal for teaching students how to think about such matters, and the mixture of disciplines and beliefs represented should reassure those who are suspicious of bias.

The four historical essays dispel some familiar myths, notably the myths of the war between science and religion, and that science has been the main driving force behind secularisation. They reveal how complex the relationship has actually been, and how the erosion of faith owes more to historical studies than to natural science. In fact theology has shown a remarkable capacity for absorbing fresh scientific insights. It has been widely recognised from the start that scientific discoveries may have theological implications, but that although both science and theology claim a cognitive content, the kinds of knowledge entailed are not the same. Reality is what it is, but knowledge of it always entails selection and interpretation. How it is seen depends much on the perspective of the viewer, and not least on whether, as in the case of most sciences, human values and interests are deliberately excluded. The disastrous mistake made by theologians in the 18th and 19th centuries in pinning their belief in God to arguments from nature, based on quasi-Newtonian assumptions, positively invited the subsequent demise of the divine watchmaker.

Two enduring problems, inherited by theology from the Enlightenment, are how far the critical spirit can be assimilated into religious understanding, and the attempt to give some rational meaning to the notion of divine agency in the deterministic world presupposed by scientific method. The first is a major topic in part two, and the second reappears in various settings in part three.

Foundationalism, we are told in part two, is no more acceptable in theology than in science. Theology must demonstrate its entitlement to be taken seriously as an interpretation of human experience, and as part of the total web of knowledge, by its openness in principle to criticism, and by its ability to provide a more comprehensive understanding than naturalism. Neither science nor theology has to start from totally rational premises, but both have to strive towards rationality.

One essayist draws a useful distinction between epistemic heritages and warrants - the way things come to be known, and the grounds on which they are accepted. In much of theology the two are closely related, in sharp contrast to most sciences. The justification of a scientific hypothesis rarely depends on its history, whereas theology is much more bound up with its own past - a factor which often makes it harder to reach agreement. But the distinction is not absolute. In fact it would aid discussion to speak about sciences and theologies, rather than to treat both as monoliths. In terms of methodology, theology is closer to those sciences which have a historical dimension. There is also a significant area of overlap in what one author calls "control beliefs" - the deep-seated and to some extent culturally conditioned assumptions about what counts as an explanation.

These are a few of the points made in a complex and unresolved debate in part two. At its heart is the question of how to relate the real experience of being human to the kind of abstractions needed for precision and certainty. Much of the success of the natural sciences has been bought at the cost of human empathy. This is a further reason why science and theology need to be in critical dialogue.

The problem of divine agency in the world looms large in part three. A case study on "Chaos theory and divine action" brings together Karl Young, a scientist at the Stanford linear accelerator in California and John Polkinghorne, former Cambridge professor of mathematical physics and now an Anglican priest. Young argues that chaotic systems, though unpredictable in their behaviour, remain deterministic. The randomness observed in a chaotic system, including quantum uncertainty, results from necessarily incomplete knowledge on the part of finite observers, rather than from any ontological property of the system itself.

Polkinghorne takes the opposite view, believing that what we can or cannot know is a reliable guide to what is actually the case. A universe which is not wholly determined at the physical level leaves room for other forms of causality, notably what Arthur Peacocke has described as "top-down" causality. This is contrasted with the familiar "bottom-up" causality assumed in the laws governing the behaviour of elementary particles. In top-down causality the behaviour of the constituents of a system is seen as being in part dependent on the total system, rather than simply on the immediate forces acting on each of its constituents in isolation. Determinism, in his words, is a "downward emergent approximation" to this more supple physical reality. A major attraction of this conjecture is that it begins to describe a physical world in which it is possible to make sense of human agency, without explaining it away as an illusion. And if human beings can change events by willing them, it is not so hard to imagine God doing the same.

The idea of top-down causation reappears in the case study on information theory, where God's interaction with creation is described by Peacocke in terms of a continuous input of "information" which "forms" or gives shape to events "without abrogating the regularities discerned by the sciences".

It makes a third, and perhaps more convincing appearance in the case study on molecular biology. David Cole, a professor of molecular and cell biology at Berkeley, argues that "the genome predetermines all the potential states of being and behaviour for the organism, but does not predetermine the organism to any one particular state." The point is taken up by a colleague also at Berkeley, Mark Richardson, professor of philosophical theology, who explores its implications for neurobiology and elaborates Cole's tentative exploration of the concept of free will. For Richardson the idea of the emergence of different capacities at different levels of organisation provides the best theory of human abilities, particularly in the formation of purposes, which are in turn shaped from above by a network of socially constructed meanings. Top-down causality is essential if these emergent mental properties are to have any significance, but this in no way renders less important the neurobiological processes that underlie them. Indeed an awareness that our actions change bit by bit the state of the synapses between the neurons in our brain, can sharpen a sense of responsibility. William James observed long ago how the drunkard says it will not matter this time, but "down among his nerve cells and fibres the molecules are counting it, registering and storing it up to be used against him when the next temptation comes. Nothing we ever do is, in strict scientific literalness, wiped out."

In an interesting case study on sociobiology and the evolution of morality, the point is made by Philip Hefner, a professor of systematic theology in Chicago, that from a functional perspective the concept of "inclusive fitness", as used by sociobiologists, correlates with the regulative idea theologians have in mind when they speak of God. The argument is subtle, and rests on the use made of "inclusive fitness" to provide the goal and driving force that predispose individuals to invest their lives in the well-being of others. I mention it here as an example of theology bringing a not-altogether-welcome new insight into what has been claimed as a purely scientific exercise.

A review of a book as long and complex as this cannot avoid bowdlerising the arguments if it is to give any flavour of the contents. This need not matter, since most of the arguments are preliminary and unresolved. What they offer to the reader is an invitation to further discussion, and an assurance that important issues are at stake. They are issues that affect our self-understanding, whether or not their full theological implications are felt to be significant. The book is not, therefore, only for those with a particular interest in religion though, as frequently happens, most of the discussions focus on what theology has to learn from science, rather than vice versa.

There is a possible explanation of this one-way traffic in E. O. Wilson's account of reductionism, popularly known as the "sandwich theory". He pictures each discipline as between two others, one above and one below. The one below plays the role of "antidiscipline" to the one above it, in the sense that it seeks to reformulate as much of that neighbour's discipline as possible in terms of its own laws and concepts. At the same time it has to resist encroachments from its own antidiscipline below it. Thus biology tries to resist being swallowed by chemistry, which in turn resists the complete reduction of its concepts to those of physics. Wilson's own interest in the process was aroused when his role as a evolutionary biologist was threatened by the new science of molecular biology, and his development of sociobiology was in part the result of this staking out of new territory in the study of animal populations.

The interfaces between different layers in the sandwiches are areas of intense struggle and creativity, but not much meaningful interaction is possible between layers which are not adjacent to one another. The attacks on a discipline come mostly from below, which is why theology, which surely sits at the top of any conceivable sandwich, must inevitably receive from science more than it can give. The model also provides a useful warning against theologians seeking to use scientific insights too distant from theology itself. The discussion of Niels Bohr's notion of complementarity in one of the case studies - on "Quantum complementarity and christology" - illustrates the importance of finding intermediate concepts, such as the contradictions encountered on reaching the limits of language, in order to bridge an otherwise inadmissible gulf.

The traffic downwards, from discipline to its antidiscipline, consists mainly in showing that the latter's concepts are too narrow to contain all that the upper discipline includes. The concept of emergence, as already mentioned, is a good example of such resistance to reductionism, by its claim that, within a given system, genuinely new characteristics and capabilities become possible at higher levels of organisation. Biology, for instance, could not be understood in chemical terms without the use of organisational concepts that do not belong to chemistry as such. In the same manner, the main messages from theologians to scientists are reminders that there must be something wrong with a view of the world which relegates to insignificance those qualities and experiences which are most characteristically human. Explanations that explain away the explainer must be self-refuting.

Only four out of the 25 contributors to this book are British. The rest are American, and testify to the liveliness of the debate in academic circles in that country. I hope it will stimulate widespread interest on this side of the Atlantic, and will convince those who doubt whether religion and science is a proper subject for university courses. A large and well-chosen bibliography demonstrates that there is no shortage of material, and there is ample proof that the building of bridges, though difficult, is not impossible.

Lord Habgood is former Archbishop of York.