Victor Reppert

In our exchange in the book, C. S. Lewis’s Christian Apologetics: Pro and Con, edited by Gregory Bassham, David Kyle Johnson argued that four naturalistic views, property dualism, the identity theory, epiphenomenalism, and eliminative materialism, can all meet the challenge posed by a C. S. Lewis–style argument from reason. I maintain that his response fails to take into account what a consistent naturalism is committed to, and that his defenses of these positions fail to put those positions in the clear.

This dissertation is an examination of the merits of an argument that naturalism is self-stultifying because it is incompatible with the possibility of rational inference. Since naturalists are committed not only to the view that nothing exists but nature, but are also to the truthfulness of the natural sciences, such an incompatibility, if shown to exist, would be very damaging. This argument has been put forward by various persons in this century; two versions in C. S. Lewis are my primary paradigms for the argument in question. ;After a brief introduction, I begin in chapter 2 to discuss some objections put to Lewis's version of the argument by Elizabeth Anscombe. I contend that Anscombe's objections, while effective against the first edition argument, fail to refute Lewis's revised argument in a later edition of Miracles. ;In chapter 3 I begin treating Lewis's argument in the context of contemporary physicalism. In this chapter I discuss supervenient causation as a way of accounting for causation involving propositional attitudes. I conclude that no version of physicalism that fails to affirm the strong supervenience of propositional attitudes upon physical states can escape the charge of self-refutation. ;In chapter 4 I discuss three arguments against the compatibility of physicalism with rational inference, and contend that the kind of compatibility claim the physicalist needs to escape self-refutation is fraught with difficulties. ;In chapter 5 I contend that eliminative materialism is, despite the contentions of Paul Churchland and Daniel Dennett to the contrary, clearly self-refuting. I conclude with some discussion of implications for the debate in philosophy of religion and the philosophy of mind.

In this paper I argue that the existence of human reason gives us good reason to suppose that God exists. If the world were as the materialist supposes it is, then we would not be able to reason to the conclusion that this is so. This contention is often challenged by the claim that mental and physical explanations can be given for the same event. But a close examination of the question of explanatory compatibility reveals that the sort of explanation that would have to be given for the event of, say, inferring that atheism is true, is incompatible with the event being explicable as a purely physical product of a purely physical universe.