Flaubert romancier has always claimed the impersonal character of his writing. It is a fundamental aesthetic bias for him: the writer does not speak of himself in his work, which must remain unconnected with self-expression. Flaubert is also a prolixe epistolier. Is it necessary only to see in his correspondent an exutory to the personal ascese imposed by his artistic concepts? From public to private, much more subtle relations are built. De Schweiger, by comparing the correspondence and the work and also examining the inscription of letters in literary texts, shows how literary and epistolary writing is closely linked. The expression and address, according to this system, which is the structure of the epistolary exchange, supports, as in mirror and not without tension, the emergence and development of impersonal writing.