Flaubert wrote “A Simple Heart” during the transition from Romanticism to Realism, and this comes across in his writing style. At some points in the story, Flaubert’s style is simple and precise (as he captures the bleak and mundane details of Félicité’s working-class life), and at other points it is full of rich imagery and poetic language (as he peeks into Félicité’s inner world). The following passage in the final chapter demonstrates how Flaubert moves between these two writing styles:
[Félicité] developed the idolatrous habit of kneeling in front of the parrot to say her prayers. Sometimes the sun would catch the parrot's glass eye as it came through the little window, causing an emanation of radiant light that sent her into ecstasies.
Félicité had been left a pension of three hundred and eighty francs by her mistress. The garden provided her with vegetables. As for clothes, she had sufficient to last her her lifetime and she saved on lighting by going to bed as soon as it began to get dark.
The first paragraph in this passage demonstrates Flaubert’s more romantic and poetic writing style, specifically in the narrator’s description of how the sun coming in through the window “caus[ed] an emanation of radiant light that sent [Félicité] into ecstasies.” Flaubert then immediately transitions to his more realist writing style, as he details in simple language how Félicité has been able to survive in the wake of Madame Aubain’s death (she has access to a pension and a vegetable garden, saves money by not using too much electricity, etc.).
This combination of styles helps readers understand both the practical challenges Félicité must navigate as a working-class woman and also the beauty and magic that she still has access to in life despite her class position.