Does Naturalism Make Sense?

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Naturalism is the belief that every single thing has a purely physical explanation. Materialism is the belief that the physical universe is all that exists, and nothing supernatural exists. They are two sides of one philosophical coin. Several excellent arguments have been made to refute the Naturalist/Materialist philosophy, but my favorite is found in C. S. Lewis's book Miracles(1960), Chapter 3: “The Cardinal Difficulty of Naturalism.”

In his biography of Lewis, Alister McGrath tells the story behind Lewis's argument. Miracles was first published in 1947. At the time, Lewis was a respected Oxford don and leader of the Oxford Socratic Club, a society that debated philosophical issues. On February 2, 1948, a 28-year-old Catholic woman named Elizabeth Anscombe debated Lewis regarding his arguments against Naturalism (she rejected it too, but on different grounds). While the Socratic Club was undecided about who won the debate, Lewis felt sure that he had lost and, according to his friend George Sayer (in his 1998 biography Jack), Lewis felt that his argument had been demolished. He re-wrote the chapter, taking into account the weaknesses that Miss Anscombe had revealed, and a new version of Miracles was published in 1960. Miss Anscombe went on to become a professor of philosophy at Cambridge University, and Lewis's new chapter became an excellent rebuttal to the philosophy of Naturalism.

Knowledge and Insight

Lewis presents his case much more forcefully than I can (and I highly recommend you read the book), but I will provide a simplified version of his argument using a few of  Lewis’s key quotes. Naturalism claims to be a total system, a way of explaining every single thing in the universe in purely physical terms. So Lewis starts with the premise,

"If Naturalism is true, every finite thing or event must be (in principle) explicable in terms of the Total System...If any one thing exists which is of such a kind that we see in advance the impossibility of ever giving it that kind of explanation, then Naturalism would be in ruins." (p. 17-18)

His next step is to describe what is necessary for rational thought:

"All possible knowledge...depends on the validity of reasoning...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. An argument 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." (p. 21)

Lewis quotes the evolutionary biologist J. B. S. Haldane, who wrote: "If my mental processes are determined wholly by the motions of atoms in my brain, I have no reason to suppose that my beliefs are true...and hence I have no reason for supposing my brain to be composed of atoms." (Possible Worlds, 1927, p. 209) Lewis shows how this applies to naturalism.

Cause and Effect

Then Lewis explains the difference between Cause-Effect relationships and Ground-Consequent relationships - I won't go into all of it here, but the thrust of it is that while Naturalists might be able to explain our thoughts in the Cause-Effect sense ("because my ancestors evolved bodies that require iron, I am thinking of eating steak for dinner"), we cannot explain why our reason should ever arrive at anything that is true (in the philosophical sense). Natural selection selects for survival and reproduction, not for true philosophy.

Some evolutionary psychologists have argued that knowing truth is an evolutionary advantage, but this is not obvious, and can only be demonstrated in limited situations. As Lewis points out, experience can show correlation (which has clear survival advantages), but only reason can demonstrate causation. So why should we believe that the conclusions of our reasoning coincide with truth? Our thoughts, in a closed, naturalistic system, can be explained only in terms of what caused them: our genes, our educations, our life experiences, etc. The system is ultimately deterministic - true free will is an illusion. Evolution simply doesn't have a way for truth to enter the picture. And yet, without some insight beyond our senses and (determined) mental reactions, our philosophies, including Naturalism, are sunk.

"Acts of thinking are no doubt events, but they are a very special sort of events. They are 'about' something other than themselves and can be true or false." (p. 25) If neurobiology finds a way to explain all of our thoughts entirely "within the system," that is, within the natural order, then we have no confidence that their cause has anything to do with truth, and we have no reason to believe that neurobiology is true. We have cut off the branch we were sitting on.

Outside the Natural System

Lewis points out that we all believe that we can arrive at truth by inferences; the difference between philosophies is that the Naturalist presents a theory that contradicts belief in real insight, while the Supernaturalist does not. The Supernaturalist readily admits that our thoughts are not entirely explainable within the system and need some other sort of history in order to make sense.

"The Theist...is not committed to the view that reason is a comparatively recent development moulded by a process of selection which can select only the biologically useful. For him, reason—the reason of God—is older than Nature, and from it the orderliness of Nature, which alone enables us to know her, is derived. For him, the human mind in the act of knowing is illuminated by the Divine reason. It is set free, in the measure required, from the huge nexus of non-rational causation; free from this to be determined by the truth known. And the preliminary processes within Nature which led up to this liberation, if there were any, were designed to do so." (p. 34-35)

Naturalists, to retain their belief in Naturalism, believe that there must be an evolutionary process that has allowed our brains to access real truth, and they’ve been working intently for decades to discover and explain it. They explore possible evolutionary explanations for morality, reason, awareness, emotions, and our entire inner lives.

Reasoning is a complicated activity; clearly our brains play a major role in our ability to think. There is interaction between the cells in our physical brains and what one might call consciousness or soul. But explaining the biological mechanics of thinking doesn’t explain the truth of thoughts, any more than explaining the printing press tells you if a particular book is based on a true story.

Truth in Patterns?

One might argue that “truth” can be discerned with a substantial level of confidence by the brain’s ability to relate bits of information to one another, and reject the pieces that don’t fit the pattern of the whole. Each person’s worldview can be tested against the worldviews proposed by others, to illuminate deficiencies and unseen contradictions. By this method, humanity might gradually inch closer and closer to discovering an underlying truth that reveals the way the universe really is. It’s a way of applying a method of theoretical physics to philosophy – to use the theory that explains things best (completely and coherently).

The problem with an argument like this is that for Materialists, it doesn’t resolve the original question: can a thought exist “on its own,” as a real insight, apart from the Natural system? If not, then the thought has been determined by all of the events that occurred before it; it could not have been otherwise. We are not free to think; we are determined to think. Without freedom to be right or wrong, our thoughts can only be seen as products of a process and not as insights into anything outside of the brain. Any system (such as Naturalism) that is deterministic, fails to explain insight.

We also have to consider how we relate bits of knowledge to one another. How do we know two true things cannot contradict each other? How do we know that our moral sense is accurate? How do we know that we can trust our senses? How do we know we aren’t living in the Matrix or in a dream?

Christians believe that because we are fallen creatures, some of our beliefs are false and need to be corrected. But, since God is the ultimate source of reason, every person believes many true things. Our grasp of truth varies from person to person - even though we don’t reason perfectly, we can be confident that our ability to think is grounded in God's reason.

Proof of No Proofs

Naturalists, by not allowing for any supernatural impositions, even into the conscious experience of their own minds, defeat themselves. When you set out to prove there are no proofs, if you lose, you lose. But if you win, you lose even worse, because you have burned down the house for the sake of saving the roof. It just doesn’t work.

While Christianity isn't the only possible explanation for real insights, once you see that the natural system is insufficient to explain reason, you need another explanation. I find Christianity to be the most believable supernatural worldview. The Christian faith cannot be proven true, because its most important claims are not subject to experimental testing. But its internal consistency, its record of life-changing effectiveness, its historical soundness, and its helpfulness in making sense of the universe we inhabit, the lives we experience, and consciousness itself make a strong case for the truth of Christianity.

Atheism as Religion

"Nature [as a whole independent system] is not an object that can be presented either to the senses or the imagination. It can be reached only by the most remote inferences. Or not reached, merely approached. It is the hoped for, the assumed, unification in a single interlocked system of all the things inferred from our scientific experiments. More than that, the Naturalist, not content to assert this, goes on to the sweeping negative assertion. 'There is nothing except this'—an assertion surely, as remote from practice, experience, and any conceivable verification as has ever been made since men began to use their reason speculatively."

         C. S. Lewis (Miracles, 1960, p. 34)

Naturalism is not a scientific claim. It’s really a religious system, because it makes judgements about ultimate meaning and requires faith. When we logically examine this belief, we find it lacking. Despite what some Atheists claim, assuming that Nature is a completely closed system (and denying the possibility of the miraculous) doesn't help us to learn the laws and processes of that system. Instead, it simply adds an unnecessary (and ultimately fatal) philosophical belief onto the good assumptions about the know-ability of the universe and the ability of our minds to reason.

Lewis and Anscombe

Others have made this point, but Lewis'sexplanation stands out because his logic is clear and his tone sympathetic (he had been an Atheist himself for the early part of his life).Elizabeth Anscombe, who was invaluable in shaping Lewis' argument, went on to become one of the most highly regarded philosophers of the 20th century.According to her introduction toMetaphysics and the Philosophy of the Mind(1981), she didn't remember her debate with Lewis as being especially intense, and while it was clear that he had agreed with some of her criticisms (he did re-write the chapter), she didn't think he was especially devastated by the interaction.These two great intellectuals ultimately agreed that Naturalism is not good philosophy, and there is no reason it would result in especially good science.I agree.