This short passage from Lewis is absolutely brilliant. It explains why so much contemporary literary criticism is crap. That 500 page thesis on “Transgender Identity in Shakespeare’s Sonnets”? How about “Dante: Animal Rights Activist”. Also related to this is why in high school you had to read Cider House Rules but not Milton. And that’s just the tip of the iceburg really. This helps explain all kinds of things!
I think we demand of a great poem something that can be called Wisdom. We wish, after reading it to understand things in general, or at least some things, better than we did before. Wisdom by itself does not make a great poem or even a poem at all: and the value of a poem is by no means in the direct ration to its wisdom. But the demand for wisdom remains. It is indeed so strong that critics to whom the obvious content of an old poet is mere ‘theological rubbish’ usually find it necessary to convince themselves that he had some profound wisdom of quite a different kind, some ‘real subject’ which no generation till our own ever suspected. The whole biographical bias of modern (or recent) criticism is possibly due to the desire to find wisdom in poems whereof the obvious meaning has ceased to appear wise. If Heaven and Hell, gods and heroes, the innocence of Imogen and the horrors of conscience in Macbeth, seem to man ‘rubbish’, then his last resource for restoring importance to the texts is to suppose that the poet is revealing the secrets of his own heart. The demand that to read great verse should be to grow in wisdom has not really altered.
-C.S. Lewis, Williams and the Arthuriad, p.190