Reason

It must not be supposed that I am in any sense putting forward the imagination as the organ of truth. We are not talking of truth, but of meaning: meaning which is the antecedent condition both of truth and falsehood, whose antithesis is not error but nonsense. I am a rationalist. For me, reason is the natural organ of truth; but imagination is the organ of meaning. Imagination, producing new metaphors or revivifying old, is not the cause of truth, but its condition. It is, I confess, undeniable that such a view indirectly implies a kind of truth or rightness in the imagination itself.

- Selected Literary Essays
An open mind, in questions that are not ultimate, is useful. But an open mind about ultimate foundations either of Theoretical or Practical Reason is idiocy. If a man’s mind is open on these things, let his mouth at least be shut.

- The Abolition of Man
There is a difficulty about disagreeing with God. He is the source from which all your reasoning power comes: you could not be right and He wrong any more than a stream can rise higher than its own source. When you are arguing against Him you are arguing against the very power that makes you able to argue at all: it is like cutting off the branch you are sitting on.

- Mere Christianity