The Fatal Self-Contradiction of Naturalism

"Materialism gave us a theory which explained everything else in the whole universe but which made it impossible to believe that our thinking was valid." - C.S. Lewis

Charles Colson (in his book, How Now Shall We Live?) writes:
"Scientific naturalism is incoherent and self-contradictory, for scientists must exempt themselves from the very framework they prescribe for everyone else. All humans beings are reduced to mechanisms operating by natural causes - except scientists themselves. Why? Because to carry out their experiments, they must assume that they, at least, are capable of transcending the network of material causes, capable of rational thought, of free deliberation, of formulating theories, of recognizing objective truth. They themselves must form the single glaring exception to their own theory. This is the fatal self-contradiction of naturalism."