[I'm notifying people who favorited "The Corpse Bride" because I discuss it at the end.]

Why do we write stories rather than essays (or jokes, in the case of crack-fics)? Writing a story is harder and takes longer. But a story can do some things better than an essay can. The civil rights and gay rights movements didn't succeed using logical arguments, but with fictional and true stories about black and gay individuals. A story can bring you into someone's world, make them a non-stranger to you, and suddenly you find your attitude towards them has changed, without an argument. A story can explain someone's behavior in terms of their previous experiences, and we may understand them better by imagining how we would respond to those same experiences than by following a chain of logic in a psychology journal.

This may be due to the peculiarities of the human mind. We've evolved to understand other humans, not essays. We can comprehend a person who is a mass of contradictions better than we can comprehend an essay that dissects the epistemology of a tangled philosophy. Stories are our native language, and we may perceive things in them more easily than if they were stated formally.

(More easily, not more reliably. Stories are a dangerous methodology for discovering truth. This, again, is due to the peculiarities of the human mind. See my author's comments (if you dare; they're long) on "The ones who walk away from Equestria". Certain things only "make sense" as stories because they trigger context-insensitive emotional responses that short-circuit logical thought. So storytelling is a double-edged sword: It can convey truths that can be perceived only in a story, and lies that are convincing only in a story, and it's difficult to know which you are doing at any given time.)

This is the true root of show versus tell. A story, fundamentally, shows. An essay tells.

Neither stories nor essays are mere communication. They're creative. Communication passes on chunks of information. Creativity takes chunks of information and assembles them in new ways. If a story doesn't give us any new or interesting combinations of old familiar chunks, we get the uneasy feeling that it wasn't really a story, and it wasn't.

"Showing" means, I think, that we can picture the assembly of those chunks in the real world and mentally simulate what they'll do. "Telling" means we are given the chunks, and a sentence or formula to plug them into.

That is far from meaning that body language is "showing" while adverbs are "telling". The chunks that we assemble may be entire chapters of a novel. I previously cited an example that Mystic gave about "implication outside the initial scope", quoting someone else:

There is a technique where you baldly state how a character feels or what a character thinks about something, and that statement can imply things far beyond the scope of what you wrote. If you've ever read Bubbles you might remember how the style is very simplistic, with Derpy telling the reader all sorts of things that other writers might try to show instead, like the things that makes her happy, or her favourite foods, or what might make her sad. The thing is, telling here is not an error, because what the writer was trying to portray subtly is not Derpy's emotions or her interests. The thing the writer was trying to infer here was Derpy's simplemindedness, and the relationship she has with her mother.

You are told many chunks of facts about Derpy. These chunks describe events or pictures in the world. You assemble them in your model of the world, and you see a bigger picture of Derpy emerge. That's showing, but on a higher level of abstraction than that of body language or adverbs.

A good essay uses showing to give examples of its points, and a good story may use telling to build its chunks (as in the Derpy example). So what's the difference between a story and an essay?

If the top-level creative concept is shown, it's a story. If the top-level creative concept is told, it's an essay.

Some of the same people who have stricken the adverbs from my stories have written "stories" in which the top-level concept is told. This is often the case in crack-fics; a classic example is "To Serve Man". I think it's okay in a crack-fic, since there's no need to distinguish between a crack-fic and an extended joke (think of a crack-fic as a long stand-up routine). But I'm never left satisfied by serious stories in which the top-level concept is simply told.

I don't want to give specific examples from fimfiction, but many of them are stories with twist endings. A twist makes you reinterpret a story. That means the twist has to involve the theme. But if you've avoided discussing the theme in order not to give away the twist, you haven't shown (or told) us pieces of the theme, and can only baldly tell it in the reveal. Any story where the twist is that pony W is a changeling, pony X is just imagining things, or pony Y secretly loves pony Z, is at risk of being a "story essay".

The story of the Grand Inquisitor from Dostoyevsky's The Brother's Karamazov is almost entirely "telling" dialogue. Christ returns a second time to earth, and is immediately jailed by the Catholic Church. The Grand Inquisitor explains to Christ why they must kill him, and his reasons sound convincing.

If the story ended there, it would be an essay. But it goes on for one more paragraph:

When the Inquisitor ceased speaking he waited some time for his Prisoner to answer him. His silence weighed down upon him. He saw that the Prisoner had listened intently all the time, looking gently in his face and evidently not wishing to reply. The old man longed for him to say something, however bitter and terrible. But He suddenly approached the old man in silence and softly kissed him on his bloodless aged lips. That was all his answer. The old man shuddered. His lips moved. He went to the door, opened it, and said to Him: 'Go, and come no more... come not at all, never, never!' And he let Him out into the dark alleys of the town. The Prisoner went away."

The kiss is Christ's response to everything the Inquisitor has said. We feel that Christ has won the debate, and yet no one can tell why. There is no shorter way to explain the story than the story itself, and that is what proves it is a story.

Here's one of my own stories that didn't quite work out in this respect: "Special". On a family outing, Pound Cake says that Discord is hiding behind a rock just beyond the shoreline. Everyone else thinks he's just playing, because that would be a silly thing for a god to do. The twist is that Discord really is hiding behind a rock, and he's doing it just to destroy Pound's faith in his parents and in society at large, and prepare him for a role in some larger plan.

The story before the reveal should have touched on the importance of growing up with parents you can trust, the danger in thinking you alone know the truth, and so on. Then the reveal would have been the final piece needed to assemble all of those things into a picture of how Pound should have grown up, and another picture of how he will now. But instead, I rushed to the reveal, trying to write the shortest set-up necessary for it, rather than the one that would give it meaning.

I think I did this better in "No Regrets", which was very short, but showed specific times when Twilight had avoided Derpy, explained why, and related that to her relationship with the ponies she considered friends. It gives enough pieces of story to put together in a big "show" by the end. AbsoluteAnonymous' "Two Cups of Tea" also did this pretty well. It gradually reveals Rarity's feelings and dreams, and how they are crushed, and how she can handle that.

It's harder to do with a twist ending, but I think I did all right in "The Corpse Bride", because the build-up to the reveal planted many things to show that Twilight and company were not living up to the ideals that Twilight expressed in her speech. Also, the ending reveals the twist (Fluttershy loved Discord), its cause (they are over-confident in their perceptions) and the other consequences of that cause (they had abandoned their friend; they have murdered Fluttershy). And I did all right in "Trust", which also has a twist ending, but the story before it explains the significance of the reveal to Celestia, and shows specific instances of misplaced trust.

The key distinction is whether the story leading up to the twist just plants clues about a fact that is to be revealed, or plants clues about the causes and consequences of what is to be revealed, which the reader can assemble into a theme. The latter is a story; the former is a story essay.