An ethnocritical reading of Rouault’s letter to his daughter Emma reveals the richness of the historical and cultural anthropology of Madame Bovary as a symbolic and language system, which is both polyphonic and hybrid. This article is concerned with the struggle of an oral tradition to resist the encroachment of writing. This process of adaptation to the modernity represented by writing affects the behavior of the characters but also the style of Flaubert. Particular attention is devoted to the study of systems of prediction (inextricably narrative and cultural, folk, and literate) that operate within the book. This cultural dialogism that permeates the text can be seen in the different versions of the manuscripts of this epistolary prose, where the author seems to have hesitated when confronted with the verbal and imaginary cosmologies evoked by his own writing.