[quote=Ward]At the age of 17, Lewis expressed his agnosticism in a letter sent in response to an inquiry of his beliefs, so Lewis's claim to being an atheist almost certainly occurred earlier.[/quote]
If Lewis expressed agnosticism at 17, this is not evidence of his being an atheist earlier. The two are different points of "belief", although they are frequently confused by the average person. Agnosticism is not knowing what one believes, rather than not believing in anything. Atheism is knowing that one does not believe in God.
One can be an agnostic on one's way from faith to atheism. I would suspect this was the case for Lewis, based on the several biographies I have read, (plus Surprised by Joy).
