I finished Victor Reppert's C.S. Lewis's Dangerous Idea: In Defense of the Argument From Reason. Reppert argues that human reason makes no sense on scientific materialism and philosophical naturalism. I found Reppert's arguments persuasive.
Reppert develops Lewis's argument, which can be stated as follows:
(1) No belief is rationally inferred if it can be fully explained in terms of nonrational causes.
(2) If materialism is true, then all beliefs can be fully explained in terms of nonrational causes.
(3) Therefore, if materialism is true, then no belief is rationally inferred.
(4) If any thesis entails the conclusion that no belief is rationally inferred, then it should be rejected and its denial accepted.
(5) Therefore materialism should be rejected and its denial accepted.
Dallas Willard, in his essay "Knowledge and Naturalism," argues in a way similar to Reppert. Willard's essay, in my mind, nicely compliments Reppert's work (though Willard is more technical and not as easy to read).
Willard's argument can be summarized as follows:
1. There is no place for truth or logical relations in a world where the only properties are physical.
2. Noetic unity is also impossible in such a world. ("The noetic aspect of knowing and knowledge encompasses all of the types of mental states and acts and their ways of coming together that are involved in the individual coming to know or to be in a state of knowledge.")
3. But knowledge is possible; many things are known and there are people of great knowledge.
4. Therefore naturalism must be false. "It cannot accommodate the ontological structure of knowing and knowledge."