There are innumerable editing clichés, most possessing strong underlying principles, most treacherous in application. The suggestion to ‘show, don’t tell’ is often accompanied by this quote from Anton Chekhov, as it is on the Wikipedia page:
Don't tell me the moon is shining; show me the glint of light on broken glass.
The problem? There is no strict division between the two modes of narration. For example, in the Hungarian writer Agota Kristóf’s Le grand cahier (The Notebook) the epistolary style is largely ‘told’, but in such a way that shows, reveals, a lot about the twin sibling protagonists. Their blunt, unadorned voices convey the formation of their personalities as they respond, stoically and unsentimentally, to a brutal and violent context. The choice to ‘tell’ over ‘showing’, coupled with the unreliability of the point of view, itself shows a lot. It also creates a sparse style of prose reminiscent of European fairy tales, one that is apt for the narrative, setting and metaphysics that are the blood of Kristóf’s fiction.
Moreover, telling qua telling is not inherently mistaken. It is regularly all too vital. One of the most turgid novels I ever read (it hardly merits mention) felt the need to show every minutiae of every scene. It is obvious that I do not need nor want to know every time X stands up and walks over to the sink and pours herself a tumbler of water by turning the tap and so on. Similarly, why should I be shown every sensory detail, however irrelevant to the plot?
What should we do as writers and editors? By no means do the best writers merely show, but there is a bad habit this advice helps break—a symptom of a more fundamentally erroneous assumption. Don’t tell and show. Too often there is a tendency to perfectly evoke something and then, like the nervous comedian tediously explaining their masterful joke, belabour the punch line. A writer might show a character’s nerves by describing a twitch already associated with some past trauma, but then superfluously tell us of this person’s now obvious nervousness as if we are dense or did not read the previous hundred pages.
Providing the writer does not redundantly do both at once, knowing when to tell and when to show requires understanding the principle Chekhov fully grasped: respect your reader. To engage someone in a story you have to assume their willingness to engage and their intelligence to be able to do so. Showing at the right point requires trust, especially when it is not followed up by redundant exposition. To say that someone shuffled around with a bowed head, rather than that they are cowed, means trusting that your reader will engage your text hermeneutically, actively interpreting your story.
As an editor, to excise every instance of telling is to possibly miss the subtler examples of showing—such as Kristóf’s—and eliminate potentially original voices. As a writer, to show and tell, or to never trust your reader’s reading, is to actively condescend and annoy. A good editor knows when to trust their author; a good author knows when to trust their reader.