In A Fine-Tuned Universe: The Quest for God in Science and Theology Alister McGrath seeks to recover a vision for natural theology that is ‘both securely rooted in the long tradition of Christian theological reflection and adequately adapted to our understandings of the natural world’. In particular he argues for a distinctively Christian approach to natural theology grounded upon the doctrine of the Trinity. In the first part McGrath develops and defends his account of a Trinitarian natural theology, while in the second part he explores the scientific application of this to the question of fine-tuning.
After an introductory chapter the first part begins with an account of what McGrath calls the ‘crisis of confidence’ in modern natural theology. Tracing the roots of this to the Enlightenment McGrath suggests that it was at this time that a new family of approaches to natural theology emerged, all of which asserted their ability to prove the existence of God without recourse to faith or revelation. However with the onset of postmodernism these rationalist models of natural theology have themselves increasingly come under attack. In particular, McGrath suggests, they have come to be seen as inadequate both scientifically and theologically. They are scientifically inadequate as relying on outmoded, mechanistic approaches to the natural world. They are theologically inadequate both in their tendency towards heterodox views of God and, as Karl Barth famously argued, for their attempt to construct an account of God independently of God’s own self-revelation.
For McGrath the decline of modernist natural theology is therefore not to be fought against but embraced as providing an opportunity to construct a new and distinctively Christian approach to natural theology attentive to the claims of faith. Taking his lead from C. S. Lewis’ famous statement – ‘I believe in Christianity as I believe that the Sun has risen, not only because I see it, but because by it I see everything else’ – he proceeds in chapter 3 to give an account of the main features of such a Christian natural theology. Like Lewis, McGrath holds that the Christian vision of reality possesses not only an internal coherence and consistency but an external ‘fit’ with reality. In these terms natural theology is understood not as an exercise in rational demonstration but rather as an exercise in discernment; a learning to see God in nature. Rather than seeing nature as an objective-given, this new approach to natural theology both emphasises the variety of ways in which nature can be seen and interpreted and focusses attention on the specifically Christian reading of nature. In this way it offers a holistic approach to nature, avoiding the pitfalls of the ‘God of the gaps’, which is attentive to human perception as an affective as well as analytic process.
Unlike the classical approach to natural theology as concerned with objective, rationally deducible truths, McGrath’s approach to natural theology emphasises a subjective engagement with a world that remains continually open to interpretation and reinterpretation. Aware of possible criticisms to his approach, both from a scientific and theological angle, in chapter 4 he seeks to defend himself from them. McGrath stresses that his approach to natural theology while influenced by postmodern concerns has not lost its bearings in objective reality. Maintaining the priority of ontology over epistemology he argues for natural theology as a ‘making intelligible’ or ‘a disclosing of the intrinsic rationality of things’. Thus, while superficially weaker in explanatory power than classical natural theology, this approach both avoids the logical and theological problems which beset the classical enterprise and, in line with traditional Christian theology, highlights the need for the healing or transformation of reason itself. Moreover in pursuing an iterative and inductive framework this reinvigorated natural theology opens itself up to a new and fruitful dialogue with the natural sciences.
In chapters 5 and 6 McGrath moves on to outline the dynamics of a Trinitarian natural theology. His claim is that Trinitarian theology provides us with a rich ontology of nature. In particular he suggests that it opens the way to a form of explanation known as unification – the identification of underlying patterns connecting together seemingly disconnected theories. Such a unifying mode of explanation is important in fleshing out the intuitive understanding of ‘fittingness’ which the new natural theology relies on. McGrath is insistent that the ontological ground of such unifying epistemologies is found in the Trinity itself. Renewing his critique of classical natural theology he argues that these by their very nature leads to a unitarian and deistic concept of God, completely foreign to the God who is revealed in Christ and Scripture. By contrast, the Christian understanding of the Trinity shifts attention to the dynamics of God’s own self-revelation. Furthermore, in the doctrine of the image of God, especially as developed in the works of the great patristic theologians Athanasius and Augustine, Christianity asserts the human being as a point of contact and congruence with God. Made in God’s image humans have the capacity to discern the Creator within the created order. Yet as fallen this capacity must be renewed in Christ in order to be effective and so natural theology, understood as a process of discernment, cannot be abstracted from Christ or the Trinitarian economy of salvation. Moreover in recognising the fallenness both of man and of the created order such a Trinitarian natural theology recognises the ambivalence of the created order – a crucial aspect of the reality we experience, but something which was glossed over by classical natural theology.
In chapter 7, looking towards the second part of his work, McGrath poses a number of questions about anthropic phenomena and their framework of explanation. Following Charles Peirce’s theory of abduction he suggests that the process of finding new explanations often begins by being confronted with ‘surprising facts’ that do not fit into our existing interpretative frameworks. In probing such surprising facts McGrath advocates the importance of counterfactual thinking – the construction by imagination of alternative possibilities to those which in fact obtain. Such counterfactual thinking, he suggests, is crucial in buttressing the inference to the best explanation characteristic of the new natural theology. For in the imagination of alternative realities it allows us to see our own reality more clearly.
In chapter 8 McGrath concludes the first part by providing a provisional interpretative framework for this Christian ‘seeing’ of reality. This he finds in the specific form of Trinitarian theology promoted by Augustine of Hippo. In particular he suggests that Augustine’s account of creation manages to affirm the continual dependence of reality on God while retaining the integrity of the natural order’s own creative development. According to McGrath Augustine achieves this through his account of the ‘seminal reasons’ as potencies implanted by God at creation and actualised progressively through divine providence. In contemporary terms the advantage of this is in linking a scientific understanding of embedded causalities in nature and evolutionary development to a theological model of providence. In this way the theory of seminal reasons provides an important heuristic for the new approach to natural theology.
In the second part McGrath considers the scientific evidence for the fine-tuning of the universe and its possible interpretations. In chapter 9 he focusses attention on cosmology and the origin of life. As McGrath explains, the standard model of cosmology suggests that the evolution of the universe has been determined by a number of basic physical constants. If these were minutely different the universe as we know it and life in particular could not exist. To many this suggests the fine-tuning of these constants and raises questions of design and intention. While some physicists invoke the multiverse as a way of avoiding such design implications, McGrath points out both that this theory is speculative and that it is not per se inconsistent with theism. His conclusion is that under any interpretation the fine-tuning phenomena provide an important empirical fit with Christian theism. Indeed, he argues that the picture of unfolding potentialities suggested by modern cosmology is highly consonant with the Augustinian paradigm of seminal reasons implanted in creation.
In chapters 10 and 11 McGrath turns to the fine-tuning evidence surrounding life and its origins. Referring to cosmology again he points out that stellar nucleosynthesis of the essential elements for life requires incredibly fine-tuning of atomic resonance levels. In similar vein he highlights the highly specific physical and chemical properties of carbon atoms and water molecules necessary for the evolution of life. Such scientific facts he suggests are legitimately open to anthropic interpretation – the chemical properties of carbon and water were designed this way in order to support life. Indeed, McGrath suggests that the usual argument raised against such anthropic interpretation – that nature tunes itself through a process of natural selection – simply begs the question of how such potentialities were intrinsic to nature in the first place. This is a point that he reiterates in chapter 12 in his examination of the chemical constraints of biological evolution. Here McGrath points out that transition metals like manganese could not play their role in catalysing biochemical reactions crucial for life were it not for the extreme fine-tuning of their quantum mechanical properties. The fact that biological evolution is chemically constrained means that questions of fine-tuning cannot be avoided. From a theistic perspective of course this fine-tuning provides no problems and once again McGrath argues that the Augustinian notion of seminal reasons provides a fruitful heuristic for understanding the interplay of intrinsic potentialities and their external activation.
In chapters 13 and 14 McGrath turns finally to consider evidence for the fine-tuning of biological evolution in terms of both its mechanism and its directionality. Following Charles Kingsley, McGrath argues that the capacity for things to make themselves is not only a fact requiring of explanation but also something indicative of God’s continual abiding presence in his evolving creation. While natural selection is often invoked to explain away anthropic considerations in evolution McGrath argues that this misses the point in failing to offer any explanation as to how this capacity of self-shaping arose in the first place. In order to explore this point McGrath highlights the notion of evolvability as the ‘organism’s capacity to generate heritable phenotypic variation’ and raises the important question of whether evolvability is itself a selectable trait. If so then he raises the real possibility that evolvability could be fine-tuned, bringing evolution within the sphere of anthropic considerations.
Taking the offensive, McGrath then points out that the neo-Darwinian paradigm of evolution by natural selection has been increasingly coming under attack within the scientific community itself. This opens once again the question for so long dismissed of whether evolution possesses an inbuilt teleology or directionality. While Stephen Jay Gould famously claimed that rewinding the ‘tape of life’ would always yield different results, McGrath highlights the research of Simon Conway Morris and others which reveals convergent patterns in evolution. In these terms evolution can be understood as tending towards a limited number of stable configurations, progressively advancing from one stable configuration to another. As McGrath suggests notions of convergence are highly susceptible to teleological and theological interpretations. Yet in advocating a teleology of evolution he distances himself from Aristotelian or Kantian a priori approaches, preferring the a posteriori understanding of Pierce. In explaining biological teleology as a complex interaction of intrinsic potential and external activation McGrath again appeals to an Augustinian account of seminal reasons.
In his final chapter McGrath turns to consider the key scientific concept of emergence: the development of novel, unpredictable properties and behaviours at increasing levels of complexity. He suggests that emergence is of importance for theology in indicating creation both as dynamically evolving and as hierarchically stratified. In indicating an emergent world shaped by the interaction of actuality and potentiality McGrath argues that Augustine’s seminal reasons once again are revealed as highly relevant for contemporary natural theology. In marrying creation and providence together they further provide an important overall framework for discerning the ongoing work of the Triune God.