These posts on Lewis’s book about miracles are part of a parallel series I am doing on Lewis and Heschel. See “God in Search of Man, #1” and “Miracles (C.S. Lewis), #1” for more explanation on my rationale.
The argument that miracles are inherently impossible is called Naturalism. Naturalism means that only Nature exists. Anything which is outside of Nature, Lewis calls it an interlocked system, is imaginary.
Lewis’s third chapter is called “The Cardinal Difficulty of Naturalism.” A modern philosopher, Victor Reppert, calls it C.S. Lewis’s Dangerous Idea (in his book by that name).
What is the problem with saying miracles are impossible because they are Supernatural and Supernatural things are impossible?
First, a disclaimer. Philosophy cannot really “prove” anything. So the point of Lewis’s argument is not, in my mind, to raise an unassailable objection to Naturalism or a beyond-doubt argument for miracles. Philosophy by nature doubts better than it proves.
Having said that, I find Lewis’s argument here a tough one for a person to maintain. It shows the high cost of being a Naturalist.
What is knowledge? We have nothing but our sensations. From these we infer various ideas about the meaning of our sensations. All possible knowledge, then, says Lewis, depends on the validity of reasoning.
Lewis points out that the Naturalist has a hard time explaining the validity of reason. Naturalism (and Lewis does make the distinction between Materialism and Naturalism, but suggests both views are liable on this point) refutes itself.
If reasoning nothing more than moving particles of matter or energy in my brain, then I have no basis to trust knowledge as a valid concept.
Put another way, consider that, reasoning (certainly for a Naturalist and also for Theists who accept evolutionary biology) used not to exist. How did it come into existence? There was no Designer; and indeed; until there were thinkers, there was no truth or falsehood. Thinking must have evolved by natural selection.
But how would this happen? When our thoughts and sensations were subrational, what mechanism made them capable of knowing truth and making inferences that are fact?
One answer is that thinking simply means thoughts that are useful (a different category than “true”). In our experience we determine that some inferences “work” and some don’t. It enables us to set a bone and build a bridge and make a Sputnik. Knowledge may not be about truth but only pragmatism.
But if we accept that then no more theology, no more ontology, no more metaphysics . . . but then, equally, no more Naturalism.
Or someone might say that since truth is true, it was inevitable that we would develop the ability to “sense” truth. Lewis makes a long argument about the difference between Cause and Effect thinking (dynamic connection between events) and Ground a Consequent (logical inference) thinking.
We’re asking what the cause of reason might be in the evolutionary process. But the Naturalist who says reason was inevitable is using a ground and consequent argument. Since I’d rather not make this post long and involved, let me say simply: the Naturalist cannot explain how thinking that arrives at knowledge came about. This imposes on him the very embarrassing task of trying to show how the evolutionary product which he has described could also be a power of “seeing” truths.
But Supernaturalists need not worry about this problem. We do not believe there was ever a time before rational thought. Reason, the reason of God, is older than Nature.