Quote from the book "Christian Reflections"

Now, his own reason has become the object: it is as if we took out our eyes to look at them. Thus studied, his own reason appears to him as the epiphenomenon which accompanies chemical or electrical events in a cortex which is itself the by-product of a blind evolutionary process. His own logic, hitherto the king whom events in all possible worlds must obey, becomes merely subjective. There is no reason for supposing that it yields truth.