Sorrow and literature and the elements of the novel

Yes, I have posted recently on some sad books, in particular Stoner, one of the saddest and most moving novels I have read in many years, and Shirley Jackson's We Have Always Lived in the Castle, sad in a completely different way as it's not the characters that we feel deeply for (actually, I hardly feel for them at all and probably won't even finish reading this novel) but the author herself and what this strange novel reveals or confirms about the social ostracism she experienced in her own life in a conservative NE town. Are all great novels sad in some way? Is sorrow a driving force in great fiction? I can't quite agree with that but would say that all great novels involve a conflict - some kind of obstacle or condition that a character or several characters must confront and overcome - this "conflict" is a modern version of what Aristotle called the "action" of a work of literature (drama, in particular). Obviously a character faced with a conflict, obstacle, or problem will be in jeopardy in some way - so there is an element of stress, discomfort, and concern in all novels, to one degree or another - the degree of its development will determine (along w/ the author's skill) our empathy for the character(s). A second element in great literature/fiction is, I think, that novels involve a "journey" of some sort - can be from place to place (the Odyssey ... or from Hannial to Cairo) or point in time to point in time (Ulysses) or even an interior journey of growth and development (or birth to death) - in any event all of these are a journey in some way from innocence to experience, and in great fiction we experience the same journey, along with the characters (this is similar to the classical definition of "story," or the story arc, in cinematic terms). Whereas the plot or the action necessarily involves conflict, difficulty, sorrow, trouble, or danger - the "story" does not - in tragic mode the "story" may be sad or piteous; in comic mode, not - as the comic novels (in the broadest sense, not humorous or witty novels) end in social inclusion or marriage or even glorious and hopeful independence (heading out for the territories). But comic novels (and comedies) have their own conflicts and dark sides, often hidden - my first critical writing (my dissertation and my book on Shakespeare's comedies) were entirely devoted to revealing some of the social conflicts in S's comedies that had gone unrecognized by generations of critics for literally hundreds of years. What did it get? Ostracism, I guess.