What does a novelist do for us?

Partly prompted by a recent debate in the comments section of Bookninja over Yann Martel's recent challenge to the Prime Minister (which led some contributors to the site to debate the importance of literature)--and partly just by my own interest in the question, here's an excerpt from an essay by Leslie Stephen called "The Moral Element in Literature" that I have been editing for the anthology I'm working on. Stephen is considering, among other things, why (in his opinion) novelists fail aesthetically when they write too much "with a purpose." Such efforts as, to use his example, Dickens's attack on government bureaucracy by way of the Circumlocution Office in Little Dorrit "implies a confusion of function," he suggests. And yet "if a poet should not have the same purpose as the politician or the economist," the conclusion is "certainly not that he should have no purpose. To have no purpose is simply not to be a reasoning being." So if poets or novelists should have no direct practical aim or purpose, or not seek to prove particular theories about the world, what can they do for us? Here's part of Stephen's answer:

He shows us certain facts as they appear to him. If we are so constituted as to be unable to see what he sees, he can go no further. He cannot proceed to argue and analyse, and apply an elaborate logical apparatus. There is the truth, and we must make what we can of it. But, on the other hand, so far as we are in sympathy with him, the proof--if it be a proof--has all the cogency of direct vision. He has couched our dull eyes, drawn back the veil which hid from us the certain aspect of the world, and henceforward our views of life and the world will be more or less changed, because the bare scaffolding of fact which we previously saw will now be seen in the light of keener perceptions than our own.

Elegantly put. But how close is Stephen coming here to James's idea of being "one of those on whom nothing is lost"? The emphasis on perception over action (currently very trendy in ethical/philosophical approaches to literature) leaves me dissatisfied, for reasons I have discussed in some of my academic writing. Still, Stephen does suggest a role for the novel in the world, albeit an indirect one. After all, if we never changed our views of life, we would never seek to change our, or others', experience of it.