It is not hard to enumerate the assets that Lewis brought with him when he set out to be a writer. First of all, intelligence. His mind, sharpened by lifelong training, was formidable in its power and precision. One can disagree with him to the point of fury, but not condescend. Coupled with the superb mind was solid erudition. He was master of classical, medieval, and Renaissance literature, so much at home in it that he could make use of its symbols and themes with unconscious ease and grace. Greek and Roman mythology and the legends of the Celts and Germanic peoples were as much a part of his literary frame of reference as the Bible. His books grew out of the collective memory of Western mankind.

Lewis brought to traditional mythology as much as he took from it. His vivid imagination could transport his mind to the...