The first argument against naturalism that I want to explore comes from C. S. Lewis. (If you’re unfamiliar with the concept of naturalism, see my previous post.)

C. S. Lewis explains that in order to show that naturalism is inadequate, all you need to do is identify one thing that cannot be explained in a naturalistic way. Naturalism says that there are no outside influences on the earth, that nothing happens in our universe that does not have purely natural, scientific explanations. To argue against naturalism, then, you don’t need to demonstrate that nothing happens according to natural principles, only that something doesn’t operate according to purely natural principles.

Lewis points out that “all possible knowledge…depends on the validity of reasoning.” In other words, if we are going to know anything about our world, we need the ability to reason, and we need to be able to trust our reasoning. Some scientifically minded people will say that they base all of their knowledge on science rather than on reasoning. But that’s not true. A scientific experiment needs to be interpreted, and this interpretation requires reasoning. Beyond that, the experiment itself needs to be set up in a certain way, and this too requires reasoning.

So back to Lewis’ point: if we are going to know anything about our world, we need to be able to trust our ability to reason. Yet the naturalistic worldview offers us no basis for trusting our reasoning. The certainty that we get from our processes of reasoning amounts to nothing more than a feeling in our minds. What objective scientific existence do the conclusions of your logic have? They only existent within our minds. They come only as decisions, feelings of certainty. They cannot be “scientifically” confirmed.

Lewis says that “unless human reasoning is valid no science can be true.” But a naturalist cannot account for human reasoning naturalistically. In order to reason effectively, we need to be able to rely on certain “laws of logic.” These laws include things like the law of noncontradiction, which states that “A” cannot be both “B” and “non-B” at the same time and in the same sense. Without these laws of logic—laws that we follow intuitively every day without thinking about them—we would not be able to reason.

But these laws of logic cannot be scientifically verified. How do you scientifically verify a law of logic? Yet we all understand that these laws exist, and that reasoning does not work without them.

To apply Lewis’ argument, we have found with the laws of logic a case of something that cannot be explained in purely naturalistic terms. They cannot be scientifically verified. Again, this doesn’t mean that nothing operates according to scientifically verifiable principles, only that there are some things that can’t be explained in this way. Thus the naturalistic worldview is inadequate. It is insufficient as an explanation for the way our world works.

To put it another way, the naturalistic worldview is self-referentially absurd. This means that when you apply the standards of naturalism to itself, the whole thing breaks down. Naturalism claims that something must be scientifically verifiable in order to be true. But that claim cannot be scientifically verified. So when we apply the system to itself, when we make it self-referential, the system is absurd.

In the next post, I will offer another argument against naturalism, this time by Richard Taylor. His argument is both a little more fun and a little easier to understand (I think). But for that, you’ll have to wait till Monday.

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Mark Beuving currently serves as Associate Pastor at Creekside Church in Rocklin, CA. Prior to going back into pastoral ministry, Mark spent ten years on staff at Eternity Bible College as a Campus Pastor, Dean of Students, and then Associate Professor. Mark now teaches online adjunct for Eternity. He is passionate about building up the body of Christ, training future leaders for the Church, and writing. Though he is interested in many areas of theology and philosophy, Mark is most fascinated with practical theology and exploring the many ways in which the Bible can speak to and transform our world. He is the author of "Resonate: Enjoying God's Gift of Music" and the co-author with Francis Chan of "Multiply: Disciples Making Disciples." Mark lives in Rocklin with his wife and two daughters.


  1. In case anyone is interested, Lewis makes this argument in his book Miracles, though in the previous post I mentioned that I picked up on this argument (and the one I’ll use for Monday) from Ronald Nash’s book Life’s Ultimate Questions.

  2. Interesting. I’m a questioning metaphysical naturalist. As a science major I agree that we have to have our own interpretations of scientific results–new studies are performed because we realized we were too hasty in our assumptions!

    • Thanks for sharing that nericay. Our discussions of these things would be so much more amicable and constructive if we were all willing to acknowledge our underlying assumptions and put those to the test when necessary (as we are both trying to do).