Ah well, I've got the bit between my teeth now. This is a famous piece from Lewis:
"Supposing there was no intelligence behind the universe, no creative mind. In that case, nobody designed my brain for the purpose of thinking. It is merely that when the atoms inside my skull happen for certain physical or chemical reasons to arrange themselves in a certain way, that gives me, as a by-product, the sensation I call thought. But if it is so, how can I trust my own thinking to be true? It's like upsetting a milk jug and hoping that the way the splash arranges will give you a map of London. But if I can't trust my own thinking, of course I can't trust the arguments leading to atheism, and therefore have no reason to be an atheist, or anything else. Unless I believe in God, I can't believe in thought; so I can never use thought to disbelieve in God." C.S. Lewis, The Case for Christianity.
This is just embarrassing, and the guy was a professor, wasn't he? 'Unless I believe in God, I can't believe in thought'. It's quite sad, I suppose, but also anti-science, and just stupid.