Obooki tells us that
I can’t rightly say that my life has ever been changed by the reading of a novel. . .and more than that, I can’t think of any novel that has changed my thinking about life, the way I conceive the world, this matter of existing. - Which is to say, I guess, that I’ve never looked into novels for philosophy, for meaning; - and which may in turn be why I’m so antipathetic to novels which are largely concerned with “philosophising” or constructing philosophies, or at least the modes of interpretation which favour this approach to them (I certainly can’t think of a novelist who ever contributed anything important to human understanding; and for those about whom it is claimed, often none of it is their own thought at all, but they were themselves strongly influenced by philosophers. . . .
Since I, too, cannot think of any particular novel that "has changed my thinking about life," and since I also don't read novels "for philosophy, for meaning" and am antipathetic to "philosophizing" in novels (as well to the underlying notion that fiction is a medium for "saying something" in the first place), I want to agree with the further claim that no novelist has ever "contributed anything important to human understanding," but finally I really can't.
In the narrow sense of the term "understanding" that Obooki seems to be invoking here--"understanding" as philosophically established knowledge--it is certainly true that fiction has contributed almost nothing to the store of human knowledge. Even those writers whose work is loosely regarded as "philosophical" (Dostoevsky, for example) hardly introduce new ideas but instead reflect on extant "ideas" as embodied through character and incident (or have their characters reflect on them directly). The only original ideas to be found in novels, going back to the first recognizable examples of the form, are ideas about new ways to to exploit the literary potential of the form itself.
It is a common move when defending fiction's putative ability to advance "human understanding" to assert that it allows us to vicariously experience the lives of "other people" or to appreciate societies and cultures different from our own or some other such opportunity to expand our sympathies. Since these claims cannot hold up to critical scrutiny--there are no "people" in works of fiction, only hopelessly circumscribed verbal representations of them, no "culture" except as the faint traces discernible in idiom and other language practices (whick are even fainter in translation)--I will not appeal to the notion of "understanding" underlying them. While of course language and writing are "human" phenomena, it is the linguistic imprint of the "human" we experience in fiction, certainly not actual humans. This version of "human understanding" merely betrays the attempt to convert literature into a form of moral inquiry and instruction.
There is, however, a way in which fiction does produce human understanding, and not just feign or simulate it. According to the account of our experience of art and literature offered by John Dewey (which I have discussed in more detail in previous posts on this blog), our encounter with art can be the most alert and engaged of human experiences. In our free perception of the aesthetic (involving an act of imaginative projection commensurate with that initiated by the artist), we reach a level of pure experience, and a degree of self-awareness of experience as experience, unavailable in most other human endeavors. Via this intensification of experience, one might say that we acquire "human understanding" in the most direct and immediate sense: we more fully understand our own capacities as the creature able to both have an experience and to reflect on the nature of that experience. We realize more distiinctly what it is to be human.
Obooki suggests that at its most satisfying, the reading experience is a state of "induced reverie." This is not entirely inconsistent with Dewey's description of aesthetic experience, but I would use instead the words "sustained attention" to identify the effort involved in the most rewarding experience of art, including the art of fiction. Few other activities call forth our complete attention as thoroughly as works of art and literature potentially do, and the "human understanding" they thus afford ought to be an important enough contribution.