Naturalism is an ancient view going back to thinkers such as the ancient Greek atomists and the Latin poet Lucretius who believed that the natural world – the world of stars, planets, earth and sea and all that is in them – is all that exists. It is the world-view espoused by Secular Humanism and has become the dominant philosophy in the West in part at least because of the influence of the so-called New Atheists.
Atheist astrophysicist Carl Sagan expressed his naturalistic belief system in the opening sentence of his television series Cosmos: ‘The cosmos is all that is, was or ever shall be.’ We should note that this statement, although it is made by a scientist, is not a statement of science, but of personal belief.
Naturalism is related to materialism – so closely in fact that they are sometimes very hard to tell apart. Materialism is the view that only the material is real. It follows that materialists are naturalists. But there are naturalists who hold that mind is to be distinguished from matter. The important thing in our context is that naturalism in common with materialism insists, according to the Oxford Companion to Philosophy, that ‘the world of nature should form a single sphere without incursions from outside by souls or spirits, divine or human’. Whatever their differences, materialism and naturalism are therefore intrinsically atheistic and implacably opposed to supernaturalism.
C. S. Lewis makes a major contribution to our understanding of naturalism and to its refutation in his book Miracles. He first considers the ways in which we use the word ‘nature’. He asks us, for example, to think of sentences like the following: (1) Are those natural teeth or a set? (2) The dog in his natural state is covered with fleas. (3) I love to get away from the city and be alone with Nature.
Lewis points out that there is a common thread of meaning here. That is, what is natural is that which happens of itself, goes on of its own accord, what you will get if you make no attempt to stop it. Lewis concludes: ‘What the Naturalist believes is that the ultimate Fact, the thing you can't go behind, is a vast process in space and time which is going on of its own accord.’ For the supernaturalist, nature is not the whole show; it is the creation of God who is not himself a part of nature.
Inevitably, for the naturalist the cosmos is a closed system of cause and effect. It has no overarching purpose and it is not open to intervention from outside since there is no outside. Richard Dawkins writes: ‘An atheist in the sense of philosophical naturalist is somebody who believes there is nothing beyond the natural, physical world, no supernatural creative intelligence lurking behind the observable universe …’Footnote 1
We should note that this does not mean that naturalists necessarily believe that there is no super-intelligence elsewhere in the universe. Some do – but they believe that such an intelligence, however far advanced it may be in comparison with human intelligence, is not supernatural. Like human intelligence it is also the end product of a purposeless evolutionary process – a consequence of what Richard Dawkins calls ‘universal Darwinism’. This is a view that was common to the theogonies of the ancient world – Babylonian, Egyptian and Greek – the idea that the gods were derived from primeval matter.
For the naturalist, then, there is no supernatural God who made nature, yet stands outside it and can intervene in its processes. In particular, miracles of the type recorded in the New Testament are impossible. Death is the end, the permanent extinction of the person.
And, since naturalists hold that the universe is a closed system of cause and effect it is not surprising that most of them are determinists. For instance, Stephen Hawking writes: ‘It is hard to see how free will can operate if our behaviour is determined by physical law, so it seems we are no more than biological machines and that free will is just an illusion.’Footnote 2
Finally, since there is no transcendence, (moral) values are purely a human creation. The Humanist Manifesto puts it like this: ‘We affirm that moral values derive their source from human experience. Ethics is autonomous and situational needing no theological or ideological sanction … Human life has meaning because we create and develop our futures.’
One of the main reasons their world-view is so dominant is that naturalists claim that their world-view is the only one consistent with science. Philosopher Paul Kurtz, who drafted the Humanist Manifesto, writes: ‘What is common to naturalistic philosophy is its commitment to science. Indeed, naturalism might be defined in its more general sense as the philosophical generalizations of the methods and conclusions of the sciences.’Footnote 3
The suggestion here is that if you start with science you will end up a naturalist. However, it is clear that for many people the situation is the exact opposite.
Harvard geneticist Richard Lewontin makes it abundantly clear that his naturalistic, indeed, materialistic convictions do not derive from his science. He writes:
Our willingness to accept scientific claims that are against common sense is the key to an understanding of the real struggle between science and the supernatural. We take the side of science in spite of the patent absurdity of some of its constructs … in spite of the tolerance of the scientific community for unsubstantiated just-so stories, because we have a prior commitment … to materialism. It is not that the methods and institutions of science somehow compel us to accept a material explanation of the phenomenal world but, on the contrary, that we are forced by our a priori adherence to material causes to create an apparatus of investigation and a set of concepts that produce material explanations, no matter how counterintuitive, no matter how mystifying to the uninitiated.Footnote 4
Lewontin's faith commitment to materialism is self-confessedly not rooted in his science but in something completely different, as becomes clear from what he next says: ‘Moreover that materialism is absolute, for we cannot allow a Divine foot in the door.’Footnote 5 This statement, be it noted, is, again, a statement by a scientist, but it is not a statement of science. It is simply a statement of what Lewontin believes – a confession of his materialistic faith.
It is critically important to be aware of what is going on here since we are constantly told that science and belief in God are at war. This is clearly a simplistic and misleading reading of the situation and an obvious way to counter it is to observe that there are leading scientists who believe in God and there are leading scientists who do not – for instance take two Nobel Prizewinners for Physics: Steven Weinberg is an atheist, William Phillips is a Christian.
There is a real conflict, though, not between science and belief in God, but between the world-views of naturalism and theism.
One of the difficulties of getting this point across is that many atheist scientists think that theism is a faith system whereas their naturalism, being ‘scientific’, does not involve faith. This is nonsense. Their confusion arises from the fact that they have redefined faith to mean ‘belief where there is no evidence’ – and since they, the naturalists, claim to believe their naturalism on the basis of scientific evidence, they therefore do not need ‘faith’.
The normal everyday meaning of ‘faith’ is ‘trust, reliance on, belief’ whose degree of justification of course varies according to the evidence on which it is based. A bank official does not trust or believe without evidence that you can pay back a loan you are requesting, and we (usually) have good reasons to trust in/believe in our friends.
Naturalists believe their naturalism but think that it is not a blind faith but is based on scientific evidence. They also think that belief in God, however, is a blind faith. But then they would be wrong particularly in the case of Christianity which, like science, claims to be evidence based. This is indicated by the stated purpose of John's Gospel 20.30: ‘These things are written that you might believe that Jesus is the Christ, the Son of God and that believing you might have life in his name.’
All world-views are belief systems. They all involve faith. The key question, therefore, is: what is the warrant for that faith? What is the evidence that a particular world-view is true? Does it satisfy the criteria of non-contradiction and coherence? Does it correspond to reality?
Naturalism is essentially reductionistic. It attempts to explain the world bottom-up – for the simple reason that there is no ‘top’, no intelligent creator to be involved in top-down causation. To be more precise, naturalism espouses what is called ontological reductionism whose presence is often indicated by the tell-tale words ‘nothing but’. For instance, Richard Dawkins writes: ‘The universe is nothing but a collection of atoms in motion …’ Stephen Hawking says: ‘We are no more than biological machines.’ This is naturalistic reductionism. Of course, we can all admit that the universe is a collection of atoms in motion and that we are biological machines. But is that all there is to it?
Atheist philosopher Thomas Nagel disagrees. Reductionist materialism doesn't account for the ‘brute facts’ of existence – it doesn't explain, for example, why the world exists at all, or how life arose from nonlife. It doesn't begin to explain the fundamental beliefs we rely on as we go about our everyday business: the truth of our subjective experience, our ability to reason, our capacity to recognize that some acts are virtuous and others aren't.
These failures, Nagel says, aren't just temporary gaps in our knowledge, waiting to be filled in by new discoveries in science. On its own terms, materialism cannot account for brute facts. Brute facts are irreducible, and materialism, which operates by breaking things down to their physical components, stands useless before them. ‘There is little or no possibility’, he writes, ‘that these facts depend on nothing but the laws of physics.’
Naturalism often leads to scientism – the belief that all valid knowledge is given by science. There is often confusion here – if by science you mean knowledge in general (science is derived from Latin scio – I know) then this is a tautology. If you mean the natural sciences then scientism is clearly false – history and many other disciplines give us knowledge and they are not natural sciences. Peter Atkins reflects this confusion: ‘There is no reason to suppose that science cannot deal with every aspect of existence.’
However, science cannot even explain itself. In order to do science you must assume the intelligibility of the universe, the principle of uniformity of nature that the future will be like the past, the laws will not change arbitrarily, and so on. Hume saw the problem (of induction) – if we do not assume the future resembles the past then past experiences are valueless to predict the future and you cannot make inferences. These do not result from science but are presuppositions that we assume in order to do it. Einstein said: ‘I cannot imagine a scientist without this faith’ – that is, faith in the rational intelligibility of the universe. Science is firmly faith based.
Unpacking this idea, Del Ratzsch points out that if we are justified in assuming these basic conditions for doing science then their justification must rest on something other than science. This means either that accepting science itself is not justifiable or there is some non-scientific justifiable basis for accepting science. Science cannot justify its own foundations – implying that there are areas outside the competence of science – and if we do accept science then there must be other sorts of grounds for believing some things. So, science cannot be the only legitimate basis for believing things. It is here that the biblical world-view becomes crucially important as it does deliver justification for doing science as the pioneers clearly saw. C. S. Lewis: ‘Men became scientific because they expected law in nature and they expected law in nature because they believed in a legislator.’
What easily gets forgotten by naturalists is that the physical sciences themselves are a result of research done by conscious minds. It is here that naturalism runs into a major difficulty. Atheist philosopher Thomas Nagel writes: ‘Consciousness is the most conspicuous obstacle to a comprehensive naturalism that relies only on the resources of physical science … if we take this problem seriously, and follow out its implications, it threatens to unravel the entire naturalistic world picture.’
In his book Mind and Cosmos Nagel questions the adequacy of naturalism – even in the subtitle: Why the Neo-Darwinist Interpretation of the World is Almost Certainly False. He writes:
For a long time I have found the materialist account of how we and our fellow organisms came to exist hard to believe. … It is prima facie highly implausible that life as we know it is the result of a sequence of physical accidents together with the mechanism of natural selection. The prima facie impression, reinforced by common sense, should carry more weight than the clerisy gives it … I would like to defend the untutored reaction of incredulity to the reductionist neo-Darwinian account of the origin and evolution of life.Footnote 6
The establishment today, he says, is devoted beyond all reason to a ‘dominant scientific naturalism, heavily dependent on Darwinian explanations of practically everything, and armed to the teeth against attacks from religion’.
‘The priority given to evolutionary naturalism in the face of its implausible conclusions’, he writes, ‘is due, I think, to the secular consensus that this is the only form of external understanding of ourselves that provides an alternative to theism.’
This is important. For theories of evolution, whatever our view of them, occupy a very interesting place in relation to world-view in the sense that, whatever the evidence for them is from natural history and science, they can be regarded as consequences of naturalism or even materialism. That would appear to be the reason why they were thought of centuries before Darwin.
Gordon Campbell in his 2003 monograph Lucretius on Creation and Evolution says:
We may reasonably assume that … all the Pre-Socratics and Atomists including the Epicureans had a similar theory that all possible creatures rose randomly from the earth in the beginning and that their number and variety was reduced by the extinction of less well adapted forms, thus producing species that were well adapted to their environment by a non-teleological mechanistic process.Footnote 7
Their views should not surprise us for, if we were to put on a naturalist hat and were asked to write about the development of life, we would come up with a theory of naturalistic evolution as it is the only option. This does not in itself show that such a theory is wrong but it can make disentangling the science from the philosophical assumptions problematic.
This is very different from other areas of science – Newton's laws, Maxwell's and Einstein's equations are not derivable from world-view principles. Indeed, trying to derive the laws of motion from Aristotle's world-view principle that perfect motion is circular held up science for centuries.
Christianity has within it the principle of contingency: God could have made the universe any way he wished, so if you wish to find out what the world is like then go and look – as Kepler did. You don't start by presuming what the universe must be like. Christianity opens up the options, naturalism restricts them.
We should notice here that Nagel regards evolutionary naturalism as an alternative to theism. It is only fair to say that there are, however, theists who reject naturalism but understand evolution as in some sense a God-guided process. Atheist naturalists, however, regard such a notion as a contradiction in terms, since for them the crowning achievement of Darwin et al. has been to show that unguided natural processes have produced everything.
In short, Nagel questions naturalism's ability to account for human consciousness and rationality. Let us look at it this way. How can it be, then, that what goes on in our tiny heads can give us anything near a true account of reality? How can it be that a mathematical equation thought up in the human mind of a mathematician can correspond to the workings of the universe out there? It was reflection on this idea that led Einstein to say: ‘the only incomprehensible thing about the universe is that it is comprehensible’. Similar reflection stimulated physics Nobel Prize winner Eugene Wigner to write a famous paper entitled ‘The Unreasonable Effectiveness of Mathematics in the Natural Sciences’.
The question we are addressing boils down to this: what authority, and hence what reliability, has our reason? Are our cognitive faculties deliberately designed to enable us to discover, recognize and believe the truth? These are vital questions since all possible knowledge depends on the validity of reasoning.
Naturalists have signally failed to appreciate the sceptical implications of their reductionism. They are essentially obliged to regard thought as some kind of neuro-physiological phenomenon. From the evolutionary perspective, the neurophysiology might well be adaptive – but why would one think for a moment that the beliefs caused by that neurophysiology should be mostly true? C. S. Lewis cites chemist J. B. S. Haldane, who pointed out long ago, if the thoughts in my mind are just the motions of atoms in my brain, a mechanism that has arisen by mindless unguided processes, why should I believe anything this brain tells me – including the fact that it is made of atoms? In particular, what grounds are there to believe that naturalism is true? In other words, the naturalists’ unguided evolution undermines their naturalism.
Atheist John Gray sees the issue clearly and makes the same point as Nagel: ‘Modern humanism is the faith that through science humankind can know the truth and so be free. But if Darwin's theory of natural selection is true this is impossible. The human mind serves evolutionary success, not truth.’Footnote 8 Indeed, it is implausible according to Nagel that non-adaptive abilities such as abstract pure mathematics, music, and metaphysics could ever have arisen by selective processes.
In light of this we might well ask: how can naturalists claim that it is on the one hand rational to believe in the theory that the evolution of our faculty of reason was not directed for the purpose of discovering the truth and on the other hand claim that it is irrational to believe that our faculty of reason was designed and created by our Maker to enable us to understand and believe the truth?
American philosopher Alvin Plantinga rams the point home:
If Dawkins is right that we are the product of mindless unguided natural processes, then he has given us strong reason to doubt the reliability of human cognitive faculties and therefore inevitably to doubt the validity of any belief that they produce – including Dawkins’ own science and his atheism. His biology and his belief in naturalism would therefore appear to be at war with each other in a conflict that has nothing at all to do with God.Footnote 9
Thomas Nagel again: ‘Evolutionary naturalism implies that we shouldn't take any of our convictions seriously, including the scientific world picture on which evolutionary naturalism itself depends.’Footnote 10
As usual, C. S. Lewis saw the issue very clearly:
Unless human reasoning is valid no science can be true. It follows that no account of the universe can be true unless that account leaves it possible for our thinking to be a real insight. A theory which explained everything else in the whole universe but which made it impossible to believe that our thinking was valid, would be utterly out of court. For that theory would itself have been reached by thinking, and if thinking is not valid that theory would, of course, be itself demolished. It would have destroyed its own credentials. It would be an argument which proved that no argument was sound – a proof that there are no such things as proofs – which is nonsense.
if … nature – the space-time-matter system – is the only thing in existence, then of course there can be no other source for our standards. They must, like everything else, be the unintended and meaningless outcome of blind forces … All that we say about ‘Nature red in tooth and claw’ … is quite inexplicable on the theory that we are simply natural creatures. If this world is the only world, how did we come to find its laws either so dreadful or so comic? If there is no straight line elsewhere how did we discover that Nature's line is crooked?Footnote 11
Naturalism is fatally flawed – its ontological reductionism undermines the foundations of the very rationality that is needed to construct or understand or believe in any kind of argument whatsoever including those that are used to defend naturalism. Naturalism, therefore, does not simply shoot itself in the foot; it shoots itself in the brain.
Another aspect of this fatal flaw in naturalism is that its claim to explain everything in terms of the physical sciences overlooks the fact that one of the now fundamental concepts of science – information – cannot be explained in such terms, not even in principle. We live in the ‘information age’ in which we have discovered that DNA is an ‘information-bearing macromolecule’. However, information, though carried on material is itself immaterial and the physical sciences cannot cope with the immaterial – nor can naturalism. That is, information is not within the explanatory power of physical reductionism and so, as Nagel says, such reductionism fails.
By contrast, the Bible is completely coherent in its explanation of why the universe is (scientifically) intelligible and why immaterial information exists. The Bible teaches that an immaterial intelligent God is ultimately responsible as Creator for the existence of both the universe and the human mind. Human beings are made in his image, the image of a rational, personal Creator, and that is why they can understand the universe, at least in part. It is therefore not surprising that there is a close link between theism and the rise of modern science in the sixteenth and seventeenth centuries.
The biblical accounts of creation are a head-on challenge to naturalism. John 1 and Genesis 1 inform us that God the Word is primary – the universe and nature derivative. That makes far more sense to me, not only as a Christian, but as a scientist.
In the end, of course, not only those of us who do science, but all of us, have to choose the presupposition with which we start. There are not many options – essentially just two. Naturalism thinks that human intelligence ultimately owes its origin to mindless matter; theism teaches that there is an intelligent Creator. I find it strange that some people claim that it is their intelligence that leads them to prefer the first to the second.
