What makes Dubliners or The Sun Also Rises more "realistic" than the work of Marquez and Borges? Why is Blade Runner a more "realistic" science fiction film than Star Wars? Since Graham Greene and Tom Clancy both write about spies, why does Greene's work feel more "realistic" despite the mammoth amount of "realistic" detail in Clancy's work? And why are the French New Wave films, which deal with murder and police chases almost as much as Hollywood does, more "realistic" than the work of Ford and Hitchcock? What of the work of genre writers, children's writers, writers of satires and farces? Can't their work be "realistic?"
Realism in the context of art is a fluid term, with multiple overlapping meanings. What makes a work of art realistic or not is a quality almost as ephemeral as what makes it good or not. A lot of my favourite writers aren't considered realistic, yet I would argue their work is.
It's common to equate realism with plausibility. A short story by Joyce or Hemingway, to take our first example, is more plausible than a story like "A Very Old Man With Enormous Wings" because the latter story involves an implausible detail (the appearance of an angel on earth). But since both are fictitious, how can one be judged "more fictitious" than another? Isn't that like saying someone can be "more dead" than someone else?
Equating realism with plausibility isn't a satisfactory answer. In the second example, of Blade Runner and Star Wars, both are speculative, yet most agree that Blade Runner is more realistic. It is the characters which make it so, not the fact that the science is more within our reach.
In every story there is a given. The given may be something outlandish, or something that generates high tension (the old ticking timebomb), or something quite ordinary. Hitchcock called it the Maguffin. It is the premise on which the story stands, and upon which "suspension of disbelief" is built. A given exists in Star Wars and in Ulysses. (The given can be that there is no given, but that's too French for this informal discussion.)
The character of the piece relates in some way to the given, whether she stops the bomb, rescues the prince, or negotiates through the streets of Dublin on a shopping trip.
The given may be plausible or not, but I would argue it is characters who are realistic or not.
Realism, to me, is a moment where a person in a story acts or thinks or speaks in a manner in which you would act or think or speak. It is a moment where, given the situation the character finds herself in, she behaves in entirely appropriately given her character. It may be a scene of high drama or it may be someone doing nothing. The context may be fantasy, mystery, romance or comedy. The character may be likeable or unlikeable, may know everything or nothing of herself. The other characters around her may be realistic or unrealistic. But those moments of realism make a character realistic.
Some examples:
1. In Lonesome Dove, the novel by Larry McMurtry and the tv miniseries, Captain Call (Tommy Lee Jones's character) has fathered a son with a prostitute. He has adopted the boy, but keeps his fatherhood a secret out of shame. Late in the novel, his son, Newt, is being attacked by a Calvary officer for refusing to sell Newt's horse. Call sees the boy being quirted by the officer and rushes over to administer a severe beating, while the rest of the officer's regiment looks on. This act of violence is perfectly in keeping with Call's nature: he sees nothing contradictory in beating a man nearly to death for quirting Newt, yet refuses to tell Newt that he is Call's son.
2. The moment in David Mamet's Glengarry Glen Ross when Aaronow and Moss ( Alan Arkin and Ed Harris in the movie) are discussing breaking into the office and Moss reassures Aaronow that they're not "talking" about breaking in, they're only "speaking" about it "as an idea."
3. In Mary Shelley's Frankenstein, the speech of Frankenstein's monster (also named Frankenstein, technically, and yes, in the book he can speak) as he carts away his dead master's body.
4. The shirt scene from The Great Gatsby.
5. The exchange in Tony Kushner's Angels in America where Prior Walter references Tennessee Williams by saying "I have always depended on the kindness of strangers" and Joe's mother says "That's a stupid thing to do."
6. MacBeth's last words, and the last words of the American MacBeth, Ahab. Warriors facing battles they can't win, aware of their fate, and yet choosing to go out fighting. I guess one could count Beowulf's battle with the dragon if viewed along those lines.
7. Raymond Chandler's example of top-knotch movie writing: An elderly man and woman board an elevator. The man in wearing a hat. At the second floor a young woman gets on the elevator. The man removes his hat.
One of the advantages of viewing realism as a product of character and not of plausibility (people, not places) is that not all characters in a work need to be realistic. Conrad's Hart of Darkness has been touted for its realism in depicting European Colonialism, but African authors like Chinua Achebe have detested Conrad's unrealistic depiction of blacks. The characters of Marlow and Kurtz can be seen as realistic without blanketing the other depictions as realistic or not. Also, this approach rescues writers such as Kurt Vonnegut, Thomas Harris, and even Dr. Seuss, whose writing may be fantastical, yet not without realism of character.