Are Naturalism and Evolution Incompatible?

Alvin Plantinga, emeritus John A. O’Brien Professor of Philosophy at the University of Notre Dame, is often described as one of the world’s preeminent philosophers. In the course of his long and decorated career, he has consistently sought to commend Christian belief and address challenges to the same.

One of his most recent efforts along these lines is the just published book Where the Conflict Really Lies: Science, Religion, and Naturalism. I’ve not yet read the book, but a recent interview indicates that one of Plantinga’s concerns is to “argue that there’s no real conflict between evolutionary theory—that is, the scientific theory of evolution apart from any naturalistic spin—and what C. S. Lewis called ‘mere Christianity.’”

No doubt making this case involves carefully defining terms, a thorough consideration of the biblical and scientific data, and a good deal of nuanced discussion. And even then, Christians who consider the Bible to be authoritative and reliable may come to different conclusions.

What really got my attention in the interview, however, was a brief mention of something I’ve seen Plantinga argue before: that the idea of unguided evolution is actually incompatible with a naturalistic worldview, i.e., one that that leaves no room for God to be involved in the workings of the universe, including the origin and development of life. Here’s interviewer Doug Wilson’s question, followed by Plantinga’s response:

In the last, much briefer section of the book, you discuss whether there is a fundamental incompatibility between naturalism and the theory of evolution.

I think that’s an extremely interesting and important point, though to argue for it properly is quite complicated; it’s hard to do in a brief compass. The basic idea, which is far from being original, is that if you are a naturalist and think that we have come to be by [unguided] evolutionary processes, then you will think that the main purpose of our cognitive processes, our mental faculties, is survival and reproductive fitness, not the production of true belief. Evolution doesn’t give a rip about whether your beliefs are true. It only cares whether or not your actions are adaptive, whether they contribute to your fitness [for survival]. From the point of view of evolution together with naturalism, you wouldn’t expect that our faculties would be really adjusted to truth or aimed at truth. They would just be aimed at fitness.

But if this is true, if our minds are aimed at mere survival, not at truth, then it’s not probable that our minds should be reliable—that is, produce an appropriate preponderance of true over false beliefs; and if that is so, then one who believes both naturalism and evolution should reject the thought that our minds are reliable. But that’s a crippling position to be in. Nietzsche is among the people who have suggested this problem. Some contemporary philosophers—Thomas Nagel, for example—have voiced the same worry, and so did Darwin himself.

To sum up, if our minds have primarily developed to adapt and survive and not to apprehend truth, then we have reason to doubt all of our beliefs, including naturalism. This is the way Plantinga put it a few years ago in a response to Richard Dawkins’ The God Delusion:

The naturalist has a defeater for the natural assumption that his cognitive faculties are reliable—a reason for rejecting that belief, for no longer holding it. …And if he has a defeater for that belief, he also has a defeater for any belief that is a product of his cognitive faculties. But of course that would be all of his beliefs—including naturalism itself. So the naturalist has a defeater for naturalism; naturalism, therefore, is self-defeating and cannot be rationally believed.

The real problem here, obviously, is Dawkins’ naturalism, his belief that there is no such person as God or anyone like God. That is because naturalism implies that evolution is unguided. So a broader conclusion is that one can’t rationally accept both naturalism and evolution; naturalism, therefore, is in conflict with a premier doctrine of contemporary science. People like Dawkins hold that there is a conflict between science and religion because they think there is a conflict between evolution and theism; the truth of the matter, however, is that the conflict is between science and naturalism, not between science and belief in God.

Readers who are interested in pursuing this further can find a longer treatment of the argument by Plantinga here (though I believe a subscription is required). Additionally, C. S. Lewis makes a similar point in the essay “Is Theology Poetry,” which can be found in his The Weight of Glory.

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