What is the theme in A Simple Heart by Gustave Flaubert?

God and organized religion is a major theme in the book. As in many of his earlier works, in "A Simple Heart" Flaubert dealt with notions of simplicity, sainthood, religious faith, and duty. Many critics have interpreted this story as a profound but veiled critique of organized religion—particularly the Roman Catholic church in nineteenth-century France— and of its unquestioning following among the bourgeoisie, or middle class. As a realist writer, Flaubert believed the artist must not express his opinions in his works.