And precisely how does that addition change the fact that Lewis refutes materialism? It doesn't. Materialism is fully refuted. If you like, I can post more proofs. I have a big library on philosophy. Materialism is indefnsible.
I have pieced together more of the Lewis quote. It is difficult, as many of the sites which have this quote do extensive piece-mealing, and almost all leave out the "nonsense" passage. The best I can do without my books (which are a thousand miles away at the moment), and by combining versions on two different sites, is:
if [naturalism] were true, every thing and event would, if we knew enough, be explicable without remainder … as a necessary product of the system … [But] all possible knowledge … depends on the validity of reasoning. If the feeling of certainty which we express by words like must be and therefore and since is a real perception of how things outside our own minds really ‘must’ be, well and good. But if this certainty is merely a feeling in our own minds and not a genuine insight into realities beyond them-—if it merely represents the way our minds happen to work—then we can have no knowledge. Unless human reasoning is valid, no science can be true. It follows that no account of the universe can be true unless that account leaves it possible for our thinking to be real insight. A theory, which explained everything else in the whole universe but which made it impossible to believe that our thinking was valid, would be utterly out of court. For that theory would itself have been reached by thinking, and if thinking is not valid, that theory would, of course, be itself demolished. It would have destroyed its own credentials. It would be an argument which proved that no argument was sound--a proof that there are no such things as proofs--which is nonsense. [pp. 11-26?]http://www.acton.org/publicat/m_and_m/2003_fall/cleveland.html and http://www.makeoutcity.com/Archives/2005/08/16/192933/But Naturalism, as commonly held, is precisely a theory of this sort. The mind, like every other particular thing or event, is supposed to be simply the product of the Total System. It is supposed to be that and nothing more, to have no power whatever of 'going on of its own accord'. And the Total System is not supposed to be rational. All thoughts whatever are therefore the results of irrational causes, and nothing more than that. [p. 28] [C.S. Lewis, Miracles (New York: The Macmillan Company, 1953)].
Now that we have more of an idea of what the full passage says, let me ask something. Do you really expect one passage from a philosopher, loaded with opinion and "philosophy" to invalidate all of science? Especially when "if" is used at least six times?
I'll leave something to the other folks on the thread, but the passage "A theory, which explained everything else in the whole universe but which made it impossible to believe that our thinking was valid, would be utterly out of court" relies on the phrase "but which made it impossible to believe that our thinking was valid." Where do you see this in science? Scientists go to great lengths to avoid errors of various kinds.
In some previous posts you indicate the bible is the primary or only source of wisdom for you, so I think I'll end my part in the discussion at this point.
Yes, I do. Many people have done it, not just Lewis. But Lewis' point is a piercing one. If all is mindless material process, then the thoughts of the materialist also fall into this category. There is no way around it. In fact, what makes you think that your colliding mental processes are any more rational than mine? There is no basis whatsoever in materialism to believe they are. I do not need to refute materialism - it is self-refuting.