apologue

A short story with a moral, often involving talking animals or objects; a fable.

"Still I must bear my hard lot as well as I can—at least, I shall be amongst gentlefolks, and not with vulgar city people": and she fell to thinking of her Russell Square friends with that very same philosophical bitterness with which, in a certain apologue, the fox is represented as speaking of the grapes.

[…] but though the mythic hero may thus be made to figure in a moral apologue, an imagination so little in keeping with his unethic nature jars upon the reader's mind.

The use of fable to persuade the audience.