In Where the Conflict Really Lies: Science, Religion, and Naturalism Alvin Plantinga addresses philosophically the perennial question of the conflict between science and religion. Plantinga’s thesis is that ‘there is a superficial conflict but deep concord between science and theistic religion, but superficial concord and deep conflict between science and naturalism’. The work is divided into four parts. In the first two parts Plantinga discusses the alleged conflict between science and religion, arguing that this is at most superficial. In the third part he argues that despite the appearance of conflict there is actually deep concord between science and religion. Finally, in the fourth part Plantinga turns the tables against atheist interpreters of science, arguing epistemologically for a deep conflict between science and naturalism.
Plantinga begins the first part by discussing the alleged conflict between the theory of evolution and Christian or, more broadly, theistic belief. Here he identifies the main source of conflict in the claim that life originated and evolved through unguided, natural processes. He recognises that if this were true it would constitute a real source of conflict and so turns to the principal arguments for its truth as propounded by the ‘new atheists’ Richard Dawkins and Daniel Dennett. Cutting through their rhetoric Plantinga expresses their main arguments in terms of the claim that there exists a plausible – that is not astronomically improbable - path through possibility space in which each stage of evolutionary development is connected to a previous stage by purely natural mechanisms. Plantinga identifies two philosophical problems with this claim. The first is that both Dawkins and Dennett assume the logical possibility of certain stages in evolution – especially the emergence of mind from mindless matter – without attempting to prove it. The second is that there currently exists no way of determining the probability of alternative evolutionary paths and thus no way of evaluating the plausibility of proposed evolutionary mechanisms. Moreover, even where such biological pathways have been mapped out, there is no way of discriminating between whether these occurred through guided or unguided natural selection. Indeed Plantinga argues that the very claim of unguided natural selection is philosophical and therefore not susceptible to scientific evidence.
The second source of alleged conflict between science and religion which Plantinga addresses is the question of special divine action – that is, divine action which goes beyond creation and conservation in being. The problem here is that such special divine action is assumed to be incompatible with modern science, not only by scientific naturalists but even by some theologians. Plantinga begins by examining this question in light of classical physics. Here he argues that it is only certain classical theories, such as Laplaceanism, presupposing the causal closure of the universe that are in conflict with special divine action. Moreover, he argues further that this claim of causal closure is philosophical and cannot be adjudicated by scientific evidence. He then moves on to examine this question in the light of modern quantum theory, arguing that here we may find even less grounds for conflict. The discussion focusses on quantum indeterminism which Plantinga suggests allows the possibility of special divine action, including miracles, even given the causal closure of the universe. Here Plantinga engages especially with the objections of theologically informed scientists, such as Arthur Peacocke, John Polkinghorne and George Ellis, against divine intervention. While he finds neither their scientific nor theological reasoning against divine intervention cogent, he suggests that modern quantum theory offers a route out of their impasse. Here he appeals to the Ghirardi-Rimini-Weber (GRW) interpretation of quantum physics which posits a regular rate of wave-function collapse. Plantinga demonstrates that under GRW it becomes possible to construct an account of special divine action which is noninterventionist and thus does not violate either causal closure or physical laws.
In the second section Plantinga moves on to consider superficial conflict between science and religion. Here he focusses on evolutionary psychology and Scripture scholarship as two cases where we find real incompatibility. In the case of evolutionary psychology scientists attempt to explain distinctively human traits such as art, music, ethics and religion in terms of adaptive fitness. Thus Plantinga refers to the theories of Pascal Boyer, Scott Atran and Justin Barrett in which religion is explained, or explained away, as a spandrel – something which is not itself fitness-enhancing but is a consequence of other traits that are fitness-enhancing. Significantly Plantinga suggests that such theories are only superficially conflicting, for while they provide a mechanism for the evolutionary emergence of religion, they do not impugn the truth of religion. For God could have brought it about that it is natural to form beliefs about the supernatural. He thus suggests that even the Freudian claim that religion is wish-fulfilment is not per se incompatible with its truth claims – for wish-fulfilment could be a mechanism that God uses to make us strive for him. Notably Plantinga finds striking parallels between evolutionary psychology and historical biblical criticism (HBC). This he sees as an Enlightenment project which seeks to understand the Bible apart from any consideration of its supernatural origin or inspiration or any of the claims of faith. The impartiality of HBC is seen by its proponents as conferring on it an objective, scientific status. However, it often leads to a complete denial of the truth claims of Christianity, demoting Jesus to the status of mere man or prophet, and in this case we obviously have an example of real conflict.
According to Plantinga the crucial philosophical question to be asked concerning evolutionary psychology and especially the HBC is whether these provide defeaters for Christian belief. In answering this he offers a detailed epistemological analysis of defeat. Plantinga’s claim is that defeaters only succeed with respect to particular evidence bases. Methodological naturalism assumes that supernatural claims cannot be part of a scientist’s evidence base. In seeking to explain religion through natural means, as in the case of evolutionary psychology and HBC, it is therefore no surprise that it produces claims incompatible with Christian belief – for its very presuppositions conflict with the Christian’s evidence base. From a broader evidence base, which takes into account the claims of faith, such claims do not produce a defeater, even where they are seen to superficially conflict. Indeed, epistemologically Plantinga claims that there is no reason why we cannot turn the tables, rationally judging the deliberations of science from the standpoint of faith.
In the third section Plantinga moves to consider what he calls the deep concord between science and Christian belief. Here he assesses first the fine-tuning argument and the claims of the Intelligent Design movement. With regard to fine-tuning Plantinga offers detailed philosophical analysis of four classic objections to this argument. He argues that three of these – observational selection, normalisability of the probability distribution and the multiverse objection – pose no ultimate problem for fine-tuning. Thus, for example, he claims that the fact that we as observers must exist in a universe which supports life, or even in an infinite multiverse in which a subset of universes are guaranteed to produce life, does not by itself constitute a nontheistic explanation for fine-tuning. However, Plantinga concedes that the problem of assigning conditional probabilities – such as the probability of fine-tuning given theism– in supporting the inference of fine-tuning to theism is a serious one. He therefore concludes that fine-tuning at the moment only offers slight support to theism.
Plantinga makes a similar claim concerning Intelligent Design. Here he examines the controversial claim of Michael Behe that there exist irreducibly complex biological structures. Here the argument returns to the question of whether it is possible to find a route through biological possibility space between primitive structures, such as a light-sensitive spot, and complex structures, such as the human eye. The claim that such structures are irreducibly complex is then equivalent to the claim that there is no such route. With Paul Draper, however, Plantinga points out that it is necessary to take account not only of direct pathways – which may or may not be unfeasible – but also indirect pathways in which different structures can co-evolve to serve other, more basic, functions and then be combined together to perform a more complex function. This he sees as a hole in Behe’s argument not addressed by the Intelligent Design movement. However, while Plantinga views the logical form of the design argument as problematic he sees it as much more compelling when rephrased in terms of what he calls ‘design discourse’ – the question of how we form beliefs concerning design. In this sense Behe’s argument, or Paley’s more famous watchmaker argument, can be reinterpreted not as proving but rather as recognising design. Here Plantinga concludes that current evolutionary theory can at most provide an extremely partial defeater for this belief in design, which fades into insignificance compared to the broader evidence base of the theist.
While both fine-tuning and design discourse suggest a measure of concord between science and religion Plantinga finds evidence for deep concord in what he calls ‘the deep roots of science’. Here he argues that the very possibility of doing science and mathematics makes much more sense given theism and the Christian doctrine of the image of God. This is because these beliefs imply the need for a close match between our cognitive faculties and reality, something which is very difficult to explain given naturalism. Indeed Plantinga argues that the fact that our universe is susceptible to mathematical structures of both astounding complexity and deep simplicity – what has often been called the ‘unreasonable efficacy of mathematics’ – cries out for an explanation. He goes on to catalogue a whole series of features of the universe, including its regularity, its law-like structure, its susceptibility to advanced mathematics, its deep simplicity and its fundamental contingency, which provide evidence for deep concord between science and religion. In particular, Plantinga suggests that the specific combination of rational intelligibility and contingency, supporting both a realist philosophy of mathematics and an inductive basis of science, is very hard to explain without invoking theism.
In the fourth and final section Plantinga moves on to argue for a deep conflict between science and naturalism, offering a reprisal of his well-known evolutionary argument against naturalism. This argument centres on the reliability of our cognitive faculties. Under the hypothesis of theism the reliability of our cognitive faculties is easy to account for, however this is not the case under the hypothesis of naturalism. For here, while we may postulate a minimal reliability to ensure predator avoidance, we can find no compelling reason why our faculties should evolve beyond this to give us access to truth about the world – a problem that Darwin himself recognised. Plantinga elaborates this argument, pointing out that for a naturalist wedded to materialism beliefs can generally be reduced to neural events or structures. Plantinga’s argument is that under naturalism we have no reason to assume a correlation between such neural structures and reality: while a frog might respond to a predator this does not allow us to say anything about the frog’s beliefs as judgements of truth about the world, but only to comment on the reliability of his predator-response mechanism. Indeed he quantifies this argument, suggesting that the probability that the content of such neural structures is reliably true given evolution and naturalism is extremely low, most likely astronomically so. His conclusion is that if there is a science-religion conflict it is between science and naturalism, not science and Christian belief.