What is naturalism and how do you refute it?
A naturalist believes that the physical universe is the sum total of all that is. There is ancient naturalism as it existed in the thinking of people like Democritus, or Epicurus, or Lucretius, and there is also contemporary naturalism. A naturalist believes that the physical universe is the sum total of all that is. In the famous words of Carl Sagan, who died in 1996, “The universe is all that is, or ever was, or ever will be.” In the naturalist view of things, whether we go back to the ancient world or look at contemporary naturalism, in the naturalist view of things, Christian supernaturalism is false by definition, as are miracles, and the existence of the Judeo-Christian God. Since the matter that makes up the universe is eternal for a naturalist like this, any belief in a divine creation of the universe is false by definition.
For a naturalist the universe is analogous to a sealed box. Everything that happens inside that box, the natural order, is caused by, or is explicable in terms of other things that exist within the box. For a naturalist, nothing—including God—exists outside of that box. And remember, that box is the cosmos, the universe, the physical universe. Therefore, nothing outside the box that we call nature can have any causal effect within the box. So, if you imagine a sealed box that constitutes the whole physical universe, all of the galaxies, the planet Earth, our solar system, the entire physical universe, and outside of that box there is nothing, nothing at all, you’ve got a fairly good picture of naturalism. It is important to notice that this box is closed and sealed tightly. Even if something perchance did exist outside of the box, it could not serve as the cause of any event that occurs within the box. Naturalists believe that everything that happens within nature, within the box, has its cause in something else that exists within the natural order.
A careful analysis of naturalism reveals a problem so serious that it fails one of the major tests that a rational person should expect any worldview to pass. In order to see how this is so, it is necessary first to recognize that naturalism regards the universe as a self-contained and self-explanatory system. If you close you eyes, think of nothing except a sealed box, and inside that box is the whole universe that we know about—deterministic, godless, materialistic, physicalist—and outside there is nothing, there is no god, there are no standards of morality that are eternal and transcendent, there are no standards of human reason that are eternal and transcendent—it’s just a box…just a box. There is nothing outside the box that we call nature that can explain, or is necessary to explain, anything that is inside the box. Naturalism claims that every individual object or event can be explained in terms of something else within the natural order. This dogma is not an accident or a non-essential feature of the naturalistic position. All that is required for naturalism to be false is the discovery of one thing that cannot be explained in the naturalistic way. If even a naturalist must concede the existence of just one thing that is outside the sealed, closed box of the natural order, then naturalism is a self-defeating system.
The Christian thinker named C.S. Lewis recognized herein the logically self-defeating nature of naturalism. Unless human reasoning is valid, C.S. Lewis argued, no arguments by any mess of metaphysical naturalist directed against Christian theism or offered in support of naturalism can be sound. The human mind has the power to grasp contingent truths, that is, things that are the case though they may not have been the case—that’s a contingent truth. But the human mind also has the power to grasp necessary connections, that is, what must be the case. The latter power, the ability to grasp necessary connections, is the hallmark of human reasoning. What I am calling a necessary connection may be illustrated by the syllogism that is so familiar to us all. That syllogism goes like this: “All men are mortal. Socrates is a man. Therefore, Socrates is mortal.” Nearly anyone can see, even without special training in logic, that the conclusion “Socrates is mortal” must be true if the other two propositions are true. Naturalists must appeal to this kind of necessary, logical connection in their own arguments for their own position, naturalism, indeed, in their reasoning about everything. But can naturalists account for this essential element of the reasoning process that they utilize in their arguments for their own position? C.S. Lewis thought not, and for good reason.
As Lewis thought, naturalism discredits our processes of reasoning, or at least reduces their credit to such a humble level that it can no longer support naturalism itself. Why is that? Listen to C.S. Lewis: “That is true because no account of the universe, including that of naturalism, 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 demolished. It would have destroyed it’s own credentials. It could be an argument which proved that no argument was sound, a proof that there are no such things as proofs, and this of course is nonsense.” What Lewis was saying, then, was this—the thrust of his argument against naturalism is this: By definition, metaphysical naturalism excludes the possible existence of anything beyond nature, but the process of reasoning requires something that exceeds the bounds of nature, namely, the laws of logical inference. Therefore, metaphysical naturalism, the naturalism of Corliss Lamont, the naturalism of Bertrand Russell, the naturalism of any atheist, of any humanist turns out to be logically self-defeating because the only way the naturalist can prove that naturalism is true is to presuppose the existence of laws of logic which naturalists are forced to deny. Naturalism is a logically hopeless and self-defeating position, and that is true of ancient naturalism and also of contemporary naturalism.
It is difficult to see how metaphysical naturalism can provide an adequate reason why human reasoning can ever be valid, or that our sense organs can be trusted. Why should we not conclude that naturalism is incompatible with attitudes of trust in either our rational or our sensible faculties? We could think that naturalism destroys our confidence in the validity of any reasoning, including the reasoning that may have led us to adopt naturalistic theories. Thus, the naturalistic theories are self-destructive, rather like the man who saws off the branch he is sitting on. The only cold comfort they—naturalists—hold out, is that some of our thought may happen to agree with reality. But on naturalistic grounds, we can never know that it does. And when we are honest about the probabilities, it appears to be enormously improbably that such agreement would ever occur.
So one of naturalism’s major problems, the reason why naturalism really should not appeal to any intelligent person in the ancient world or the contemporary world, one of naturalism’s major problems, then, is explaining how mindless forces give rise to minds, to knowledge, to sound reasoning, and moral principles that report how human beings ought to behave. Not surprisingly, naturalists want the rest of us to think that their worldview, naturalism, is a product of their sound reasoning. But, all things considered, it is hard to see why naturalism is not self-referentially absurd, logically self-defeating. Before any person can justify his or her acceptance of naturalism on rational grounds, it is first necessary for that person to reject a cardinal tenet of the naturalistic position. The only way a person can provide rational grounds for believing in naturalism is first to cease being a naturalist.