Naturalism (or the almost synonymous position of materialism) represents the philosophical position that the natural world (or the material world respectively) is all there is without remainder. At one point in his key argument against naturalism, Miracles: A Preliminary Study, Lewis states his definition succinctly, “Some people believe that nothing exists except Nature. I call these people Naturalists.” In accord with Lewis, I will generally use “naturalism” because that is C. S. Lewis’s preferred term, but sometimes I will employ “materialism” interchangeably. This philosophical position obviously presents problems for Christian faith as it points to the Source of all being beyond this material world. In this chapter, I will look at Lewis’s apologetic strategy of arguing that naturalism is self-defeating.
Whatever it is called, naturalism has again returned with renewed vigor, though not always improved insight. And with it, a combative anti-theism has arisen in our country. The prominent Harvard neuroscientist Stephen Pinker has laid down the gauntlet in this way:
The neuroscientific worldview—the idea that the mind is what the brain does—has kicked away one of the intuitive supports of religion. So even if you accepted all of the previous scientific challenges to religion—the Earth revolving around the sun, animals evolving, and so on—the immaterial soul was always one last thing that you could keep as being in the province of religion. With the advance of neuroscience, that idea has been challenged.
It seems that materialism has won the day with scientists and that, according to many, it represents the crucial contemporary argument against religious faith. It represents a crucial component of the “New Atheism” that has resulted in millions of books being sold by the likes of Christopher Hitchens, Richard Dawkins, and Daniel Dennett.
In the conflict between Christian faith and naturalism, C. S. Lewis’s next apologetic argument, even if he formulated it most definitively almost seventy years ago, still takes hold. We have a contemporary culture that hears the siren cries of naturalism. Lewis, as he moved into theism and then Christian belief in the 1930s, continued to wonder about whether life ends and is simply annihilated. I too, having grown up for my first eighteen years without religious faith and now engaging in scientific literature that so often denies a reality beyond nature, I find myself tempted by unremitting naturalism. Nevertheless, Lewis’s argument that naturalism is self-defeating is powerful, and I cannot escape its force.
Oxford in the 1940s
Though it can be argued that idealism still maintained a foothold at Oxford in the 1940s, Lewis nevertheless felt compelled to engage in dialectics against naturalism. For Lewis the big crises with naturalism first emerged in 1929, when he confessed adult faith in theism and then in 1931 when he looked specifically to Christ. No longer content simply to remain the rationalist—and thus materialist—he found that life had more to offer. In some ways, it could be argued that Lewis had a strong line of idealism running through his philosophical veins, at least in the sense described by his friend, the Oxford philosophical theologian, Austin Farrer:
Lewis was raised in the tradition of an idealist philosophy which hoped to establish the reality of the mental subject independently of, or anyhow in priority to, that of the bodily world.
Farrer does note that Lewis “moved some way from such positions,” primarily by concluding that idealism did not sufficiently take in the personal presence of the absolute in the Incarnation. He indeed calls this shift a move from “idealism,” by which he means that there is a transcendent Mind or Spirit, to full encounter with God. This God would never be contained solely by the interactions of the natural world.
Nonetheless, there was sufficient idealism in Lewis’s convictions to butt heads with the more materialist currents of his day. For example, in Oxford’s Socratic Society—where Lewis presented the two pieces (or at least parts thereof) I am analyzing—Lewis found he regularly had to impugn the arguments of Logical Positivists, who asserted that statements about a transcendent reality were meaningless. This represents a linguistic and philosophical complement to naturalism. As he wrote to his student, Dom Bede Griffiths on April 22, 1954,
Don’t imagine that the Logical Positivist Menace is over. To me it seems that the apologetic position has never in my life been worse than it is now. At the Socratic the enemy often wipe the floor with us. Quousque domine? [How long, O Lord?]
Lewis, who in many ways gloried in moving against the grain of the culture, readily argued for the irrationality of materialism. I use “irrationality” advisedly because Lewis argued that materialism did not allow for rationality and thus obviated truth as well. In materialism, things just are; they are neither true nor false. And I mean this literally—Lewis concluded that, if we take nature to be all that there is, there is no place for rational thought. That is why naturalism defeats itself. It cuts off the very branch on which it sits.
As I mentioned above, we live in an age, remarkable similar to C.S. Lewis’s… at least in this regard. The intellectual culture of the 1940s, out of which the two prominent writings, first “Is Theology Poetry” and then Miracles: A Preliminary Study, I will analyze emerged, promoted the concept that matter was all that mattered. For this reason, these two pieces are still pertinent.
Certainly not all scientists today or in the early decades of the twentieth century, were of similar minds. Some, even within the naturalist and therefore atheistic camp, saw the problems inherent in arguing that “the mind is what the brain does.” The famous geneticist and evolutionary biologist, John Scott Haldane wrote this,
It seems to me immensely unlikely that mind is a mere by-product of matter. For 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. They may be sound chemically, but that does not make them sound logically. And hence I have no reason for supposing my brain to be composed of atoms.
It is noteworthy that Lewis takes up this citation directly in Miracles, probably to demonstrate that the self-defeating nature of unremitting naturalism arose not just from a theological conviction, but from a logical one as well.
I now turn to Lewis’s specific encounters in the ‘40s with the naturalistic mindset of many scientists.
Two types of naturalism
Ultimately, Lewis was a professor of literature and therefore a specialist in the humanities and not the sciences. Most of his arguments for faith in light of what he names “the Scientific Outlook” take place in philosophy or the arts. Yet, this may be a strength because many arguments against Christian faith are presented by scientists as scientific, but are really philosophical in character.
Is there more than one form of naturalism? If so, are all forms of naturalism self-defeating? We arrive at a nexus where confusion can arise. Sometimes less scrupulous atheistic commentators may even use this misunderstanding as a rhetorical shell game, treating all naturalism as coterminous and concluding that God cannot exist in light of the advance of science. So I need to make a distinction. Science commits itself to methodological naturalism quite rightly. Science, at its core, commits to a method in which scientists look for the interactions, interrelations, and thus cause and effect in the natural world. For example, when scientists ask the question, “What is the boiling point of water?” they keep testing, hypothesizing, testing, and hypothesizing, until they find the natural causes for this effect. They conclude that, when water at sea level is heated to 100 Celsius, it begins to boil. No god or spirit is needed for that specific phenomenon of nature (other than a Creator God who put together nature itself, by I will return to that theme below). The methods of scientists become complicated in more elaborate theories—quantum theory comes to mind—but the basic commitment to find solely natural causes remains. This is proper methodological naturalism.
The issue is when this method of looking solely for natural causes elides into philosophical naturalism—that all that exists is nature. Just because science cannot test or number something does not mean it does not exist. It is here—not as a field of study, but as an understanding of the world or as a sense-of-life, where science often intersects—or even collides with—theology. Many evolutionists use the theory of natural selection and conclude that the natural world of cause-and-effect is not guided, but evokes a mindless, “pitiless indifference,” to quote Richard Dawkins in Journey Out of Eden. He sets this view against the purposeful creation by the hand of God. But, as Albert Einstein once quipped about scientists’ prediliction for numbering as an example of philosophical naturalism, “Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted.”
And, though many scientists, and atheistic philosophers, casually link methodological naturalism with philosophical atheism, there is no sound reason to do so. Here a distinction is helpful. There is a fundamental difference the study of God and the study of the natural world based. Simply there is primary and secondary causation. God is the primary cause—God undergirds and establishes all being. As the great medieval philosopher Thomas Aquinas taught, the nature of God as Creator is that being itself continually flows from God. That fact defines primary causation. God is the Cause that undergirds all other causes. Secondary causation is what human beings, and all other agents in the natural world, are given to do. Shakespeare created Hamlet and Ophelia—that is the nature of authorship. They would not exist without him, but within the story they have real interaction. They exist because Shakespeare, as it were, brought them into being. The analogy is not perfect because once the play is written, the real interactions between Hamlet and Ophelia are fixed in a way that ours as real secondary agents is not. Nonetheless, the central analogical point lies here: if Shakespeare were to have stopped writing Hamlet in the midst of its creation, the entire story would have ceased. And so too with God. God is the primary cause, but we are the real secondary causes. If God were to stop creating, we would no longer exist. At the same time, we can study the real interactions among secondary in their own right without direct reference to the first cause.
“Is Theology Poetry” on “the Scientific Outlook” and its contrast with science
I make these distinctions between primary and secondary causation and between these two types of naturalism because they are consistent with Lewis’s own. So I turn then to our first text at hand: “Is Theology Poetry?” really an oral presentation to the Oxford Socratic Club—from 1945. It is a fascinating lecture—as Lewis is wont to create—not on science per se, or even strictly evolutionary science, but on the use of evolution to create a worldview, one that challenges orthodox Christian accounts of the world. To repeat: This atheistic challenge confuses methodological naturalism (tbe basis of evolution) with philosophical naturalism. Or, as it appears in this essay, Lewis distinguishes “science” (and “real science”) with “the Scientific Outlook.” When scientists grasp this distinction, no conflict between science and God need arise prematurely. Now there may be discoveries about creation and raise questions about the Creator, but science by its nature does not have the power and right to say that all that exists is what it studies. It is as if sculptors were to assert that painting does not exist because they have never touched paint.
So Lewis held out great hope for science and faith. He held a positive assessment of science. Worth considering is what he puts in the mouth of the devil, Screwtape, in the first letter of the Screwtape Letters, the imagined correspondence between a senior devil and a junior devil, Wormwood, on how to tempt a human soul.
Above all, do not attempt to use science (I mean, the real sciences) as a defense against Christianity. They will positively encourage him to think about realities he can't touch and see. There have been sad cases among the modern physicists.
Lewis’s argument here is that “real sciences” are philosophically anti-naturalistic, a point that finds agreement with the eminent physicist Sir John Polkinghorne; quantum physics now raises up things that we cannot see or touch. With the existence of quarks, no one can see them directly, but we have to infer their existence because they make sense of material reality: “Well, quarks are, in some sense, unseen realities. Nobody has ever isolated a single quark in the lab. So we believe in them not because we've, even with sophisticated instruments, so to speak, seen them, but because assuming that they're there makes sense of great swaths of physical experience.”
In another brief essay, “Dogma and the Universe,” Lewis makes another connection between modern physics and the defeat of “classical materialism,” that nature depends on its existence on something else.
In one respect, as many Christians have noticed, contemporary science has recently come into life with Christian doctrine, and parted company with the classical forms of materialism. If anything emerges clearly from modern physics, it is that nature is not everlasting. The universe had a beginning, and will have an end.
He does note, however, “We should not lean to heavily on this, for scientific theories change.”
In his essay, Lewis takes up the question given to him: “Is theology poetry?” (This, of course, is also the title of the talk). He does not seem to enjoy the question as it stands before him, so he refines it to become whether theology is merely poetry. He, first of all, argues that theology is not just poetry—it is not really artful enough, nor is it as good as the poetry of
The charge that Theology is mere poetry, if it means that Christians believe it because they find it, antecedently to belief, the most poetically attractive of all world pictures, thus seems to me unplausible in the extreme.
Lewis then analyzes the poetry of the Scientific Outlook presented by evolution (and especially H. G. Wells) as a philosophy of progress that gradually and painfully overcomes obstacles. What Lewis names the Scientific Outlook begins with a humble of inanimate matter that gradually becomes life. It gradually emerges as dinosaurs, who die out, replaced by Man, who is also destined to die. This great myth is finally “overwhelmed in ruin.” It is a beautiful, tragic myth of Man fighting valiantly against the odds, but ultimately losing.
The reason Lewis rejected the “Scientific Outlook” lies in the self-defeating nature of the two claims “we can think” and “nature is all there is.” Here we come to the key theme of this chapter: the Scientific Outlook asserts the truth and reasonableness of its claims without thereby providing a place for reason. Or as he put it:
If minds are wholly dependent on brains, and brains on biochemistry, and biochemistry (in the long run) on the meaningless flux of the atoms, I cannot understand how the thought of those minds should have any more significance than the sound of the wind in the trees.
The Scientific Outlook tries to fit in reason in an irrational—or maybe arational—world. Lewis concludes that this move is self-defeating.
As an alternative, Lewis discovered in his own life (around his conversions in 1929 and 1931) something he argues here: Belief in a Creator God who endows humanity with reason makes entirely more sense. The divine Logos creates human reason. The primary Cause ungirds all secondary causes. Lewis says that is why he does not believe in the “Scientific Outlook,” but instead believes in Christianity, which includes reason and science. As he closes the lecture, he writes,
Christian theology can fit in science, art, morality, and the sub-Christian religions. The scientific view [such as in H. G. Wells, and I would add, Pinker] cannot fit in any of these things, not even science itself. 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.
Lewis believed that Christian theology gave grounds for reason and thus reasoning about what is true. Therefore it makes sense of science. Put another way, if science bets its existence on naturalism, then it will ultimately undermine itself.
His more sustained argument can be found in the 1947 apologetic work, Miracles, a key chapter of which (chapter three) he revised for the 1960 edition, from which I will quote.
The argument in Miracles (1947, revised 1960)
Starting with Lewis’s arguments against naturalism, I turn to his most sustained, discussed, and debated presentation, the opening chapters of Miracles, particularly the third chapter, “The Cardinal Difficulty with Naturalism.” As I mentioned above, Lewis defines naturalism simply as the belief that nature is all there is, and he also provides a more extensive definition in Miracles: Naturalism is “the doctrine that only Nature—the whole interlocked system–exists. And if that were true, every thing and event would, if we knew enough, be explicable without remainder (no heel taps) as a necessary product of the system.” He continues the essence of the argument he presented in “Is Theology Poetry?” (and elsewhere)—that in order for reason to exist there must be something greater or “above” (super in Latin) and thus there must be Supernature.
Lewis presents his argument against naturalism to kick away a support for disbelieving in miracles. If there is nothing that supervenes over nature, then miracles are impossible. If there is, however, a Supernature, then it, or God, could act in ways contrary to the nexus of cause and effect in the natural world. That a central reason he argues against naturalism.
Now Lewis’s argument against naturalism is reasonable simple. It starts with the premise that
(1) Naturalism asserts that all that exists is part of the natural, or material world, of cause and effect.
(2) Reason, being a part of all that is, must therefore be a component solely of the natural world.
(3) Yet, in order for reason to discover truth, it cannot be solely based on natural, or material, cause and effect.
(4) Therefore naturalists cannot fit reason into their system.
(5) Consequently, naturalism is false.
As a result of the well-known debate with the eminent Oxford philosopher Elizabeth Anscombe at the Socratic Club on February 2, 1948, Lewis conceded that Anscombe had pointed out flaws in his essential argument. He presented changes in the 1960 revision to Miracles, noting a key distinction between Cause-Effect and Ground-Consequent. She too, according to subsequent reflection, felt that he had admitted problems, noting his “honesty and seriousness” as a philosopher. She did not, however, conclude he destroyed, as later commentators would assert. A. N. Wilson, who, in his 1990s biography of Lewis, labored incessantly (and even cooked a few facts) to make Lewis look unworthy of serious attention repeats a somewhat tired argument that Lewis retreated from apologetics (such as Miracles) to children’s literature (i.e., Narnia) after this encounter. (Below I will note how Wilson’s mood changed significantly a few years ago.) He continues by asserting that Lewis even patterned the evil White Witch of Narnia, Jadis, after Anscombe. I find it difficult to take that sort of assertion seriously.
I have presented the critical elements of his revised presentation, not to engage them directly (others have done so effectively), but to demonstrate more that Lewis more away from argument to story, from justification to signification. Or put another way, as Michael Ward does in Planet Narnia, Lewis moved from Contemplation to Enjoyment. This is a key distinction that Lewis makes in Surprised by Joy, which he picked up from Alexander. So in 1950, when he began the “Narniad” as it is called, he wanted to enjoy what reasoning implied (a first order experience), not contemplate reason, or think about thinking (a second-order experience).
The apologetic force of this argument remains surprisingly relevant for today’s anti-theistic—I have noted Pinker and Dawkins, but there are many others. I have found myself, as one committed to the glory of scientific insight along with my Christian faith, leaning on Lewis. He does not argue that one must conclude that naturalism is self-defeating, only that that it is very likely to be self-defeating. And I have not found a rejoinder, although many have been tried, and the debate shows no signs of abating. It is not exactly an argument for Christian faith, but as he concludes in “Is Theology Poetry?” he does offer that theism—specifically, the creation of the world by a rational Creator—offers the best ground for human reason. For this reason, Lewis brings together a rigorous reasoning alongside a robust faith in God as Creator.
A final thought
Perhaps the best closer for this chapter comes from the pen of A. N. Wilson, the brilliant, but cranky biographer of Lewis who remained, for decades, a committed, atheist. Just a few years ago, he changed his mind. In an April 2009 article in MailOnline, he wrote this,
Our bishops and theologians, frightened as they have been by the pounding of secularist guns, need that kind of bravery (like Sir Thomas More’s) more than ever. Sadly, they have all but accepted that only stupid people actually believe in Christianity, and that the few intelligent people left in the churches are there only for the music or believe it all in some symbolic or contorted way which, when examined, turns out not to be belief after all. As a matter of fact, I am sure the opposite is the case and that materialist atheism is not merely an arid creed, but totally irrational. Materialist atheism says we are just a collection of chemicals. It has no answer whatsoever to the question of how we should be capable of love or heroism or poetry if we are simply animated pieces of meat.
That seems in the mode of C. S. Lewis himself. But Lewis did not stop with simply impugning naturalism—a negative accomplishment—he also presented a positive argument for Jesus Christ. That is the subject of the next chapter.
 Miracles, 5. Note: This, and in some of the following citations, are incomplete. That will certainly be remedied in a final draft of this paper.
 Atoms & Eden: Conversations on Religion & Science, edited by Steve Paulsen (Oxford, 2010), 239.
 “The Philosophical Journey of C.S. Lewis,” Stanford Online Encyclopedia.
 Surprised by Joy: The Shape of My Early Life.
 The Collected Letters of C. S. Lewis, 1950-1963: Narnia, Cambridge and Joy, Volume III, ed. Walter Hooper (San Francisco: HarperSanFrancisco, 2007), 462
 Perhaps not surprisingly, as I picked up Orthodoxy, by Lewis’s great mentor, G. K. Chesterton, the latter contains an extended section on materialism
 Possible Worlds and Other Essays.
 Dawkins, River Out of Eden: A Darwinian View of Life, 132-33.
 Just to be clear: It was read on November 7, 1944 and published in The Socratic Digest in 1945.
 The Screwtape Letters, Letter I.
 May 29, 2008 National Public Radio interview with Krista Tippett. See http://being.publicradio.org/programs/quarks/transcript.shtml.
 “Dogma and the Universe,” in God in the Dock: Essays on Theology and Ethics, edited by Walter Hooper (Grand Rapids: Eerdmans, 1970), 38-9.
 “Dogma and the Universe,” 39.
 The Weight of Glory, 78.
 The Weight of Glory, 81.
 Miracles, 12.
 C. S. Lewis: A Biography.
 Cf. Reppert’s book, C. S. Lewis’s Dangerous Idea.
 Michael Ward, Planet Narnia, 218-20.
 Beversluis, The Rational Religion of C. S. Lewis.
 One prominent example is Daniel Dennett.