"For novelists, there is one big idea, always present and always demanding of attention. It goes something like this: what does it mean to be human? How can we conduct our lives to best effect? For many readers, the novel is as close as we ever come to philosophy. And it may be quite close enough. Ideas, big and little, should never be discounted in the novel because "it's only fiction." It's fiction, all right, but not only."
January 1, 1970
https://en.wikiquote.org/wiki/Novel