The nature of literary truth along with the effects of reading literature are the issues that loom largest in my thinking about literary fiction. 
While I am far from a well-informed student of literature, my sense is that both are rarely written about or systematically discussed in literary forums. Nor are they exactly hot topics on the Web.

The topic interests me because I come from a tradition that regards the “truth” as the exclusive domain of science. It is only recently that I have come to see how wrong I was and how limited that tradition is.

Indeed, I now realize that most of the passages from the literary fiction that I have collected in my Commonplace Book convey an important truth about myself or the world around me. These truths are, in my view, indistinguishable in principle from any empirical truth.

The truths that I find in these passages, like most of those in my commonplace book, may be uniquely true for me. That is the wonderful thing about literature: it makes no claims of universality, it does not intend to be true or false in the way an empirical proposition is.

Rather we read ourselves into literature without concern, as we are in science, for whether or not the passage is true for others, and if so, for how many and to what degree. Instead, the truth of any given passage is immediately true for the reader because it corresponds to his or her experience or provides a language for it in a way that had not been available before. “Yes,” we say, “that is true for me. This is my story. That’s exactly the way I felt. Or I had not realized its truth until I saw it on the page.”

In addition to those cited earlier the passages below are among those that I have collected on the subject of literary truth.

…we never get closer to the truth than in a novel. Louis Begley

Currently I am writing volume one of my autobiography, and thinking about some of the people and events that went into The Golden Notebook, I have to conclude that fiction is better at “the truth” than a factual record. Why this should be so is a very large subject and one I don’t begin to understand. Doris Lessing

“The reason why we like a book is because we say, Yes, because life is like that, and the reason why we stop reading certain kinds of childish books is because we say, Good story but life’s not like that. The whole question of recognition is terribly important and that’s why as you get older your reading experience inevitably gets richer because you have more of your own experience to bring to it.” Tim Parks cited by Patrick Kurp in Anecdotal Evidence July 24, 2007

The variety and interest of existence had struck us, through
 literature, as being more real than our factual origins.

 Shirley Hazzard Ancient Shore
We look to fiction for images of reality—real life rendered as vicarious experience, with a circumstantial intimacy that more factual, explanatory accounts cannot quite supply. John Updike New Yorker 1/26/04

Its [literature] cultural importance derives...from its success in telling us things about ourselves that we hear from no other quarter." Salman Rushdie

"He liked novels because they dealt with the incommensurable in life, with the things that couldn't be expressed another way." Richard Ford in Quality Time New Yorker January 31, 2000.

What am I looking for here? Nothing much and yet everything: amusement, an expanded knowledge of how other people live--and lived--and, chiefly, those truths of the heart that, for complicated reasons, are otherwise hidden from us and unavailable anywhere else but in literature. Joseph Epstein Surfing the Novel Commentary January 2002

…there is a certain audience that wants to hear the truth again. There are truths told in this play [“Long Day’s Journey Into Night.”], as in any great classic, that have to be heard over and over and over again. Brian Dennehy

I was changed by literature, not by cautionary or exhortatory literature, but by the truth as I found it in literature. I recognize the world in a different way because of it, and I continue to be influenced in that way by it. Opened up, made more alert, and called to a greater truthfulness in my own accounting of things, not just in my writing, in my life as well. It did that for me, and does that for me, and no one touched by it in this way should have any doubt of its necessity. Tobias Wolff. Paris Review Interview #183

I think a great book--leaving aside other qualities such as narrative power, characterization, style and so on--is a book that describes the world in a way that has not been done before; and that is recognized by those who read it as telling new truths--about society or the way in which emotional lives are led, or both--such truths having not been previously available, certainly not from official records or government documents, or from journalism or television. Julian Barnes Paris Review #157