“Our comparison of the work and reality is automatic and instantaneous. To say that a style feels appropriate to a subject is to say, then, that we believe it in some way helps us to see the subject truly.
Fiction seeks out truth. Granted, it seeks a poetic kind of truth, universals not easily translatable into moral codes. But part of our interest as we read is in learning how the world works; how the conflicts we share with the writer and all other human beings can be resolved, if at all; what values we can affirm and, in general, what the moral risks are. The writer who can’t distinguish truth from a peanut-butter sandwich can never write good fiction. What he affirms we deny, throwing away his book in indignation; or if he affirms nothing, not even our oneness in sad or comic helplessness, and insists that he’s perfectly right to do so, we confute him by closing his book. Some bad men write good books, admittedly, but the reason is that when they’re writing they’re better men than when they beat their wives and their children. When he writes, the man of impetuous bad character has time to reconsider. The fictional process helps him say what he might not have said that same night in the tavern. Good men, on the other hand, need not necessarily write good books. Good-heartedness and sincerity are no substitute for rigorous pursuit of the fictional process.
… It is sometimes remarked, not by enemies of fiction but by people who love it, that whereas scientists and politicians work for progress, the writer of fiction restates what has always been known, finding new expression for familiar truths, adapting to the age truths that may seem outmoded. It is truth that, in treating human emotion, with which we’re all familiar, the writer discovers nothing, merely clarifies for the moment, and that in treating what Faulkner called, “the eternal verities,” the writer treats nothing unheard of, since people have been naming and struggling to organize their lives around eternal verities for thousands of years. […] But the fact remains that art produces the most important process civilization knows. Restating old truths and adapting them to the age, applying them in ways they were never before applied, stirring up emotion by inherent power of narrative, visual image, or music, artists crack the door to the morally necessary future. […] This is not to say that great writing is propaganda. But because the fictional process selects those fit for it, and because a requirement of that process is a strong empathetic emotion, it turns out that the truth writer’s fundamental concern—his reason for finding a subject interesting in the first place—is likely to be humane. He sees injustice or misunderstanding in the world around him, and he cannot keep it out of his story.”
— John Gardner in The Art of Fiction