Definition of Tone
The tone of “A Simple Heart” is primarily a compassionate one. The narrator stays close to Félicité’s perspective for most of the story, sometimes even channeling her thoughts directly. This stylistic choice—called “free indirect discourse”—signals that a narrator feels sympathy for a given character, as they open up to experiencing said character’s thoughts and feelings directly rather than merely reporting (or commenting) on them.
All that said, there are a few notable times in the story when the narrator’s own opinions emerge. Take the following passage, for example, when the narrator describes Félicité’s relationship with her long-lost sister Nastasie’s family:
Félicité became very attached to them. She bought them a blanket, some shirts and a cooking stove. They were obviously out to take advantage of her. Madame Aubain was annoyed that Félicité was not more firm with them.