Perspective fonctionnelle de la phrase et diachronie : le passage de l’ancien français au moyen français

The purpose of this article is to show how the concepts and the methods of FSP can be applied to the diachronic study. By leaning on a corpus of Old French and Middle French texts, we observe at first the specificity of the communicative dynamism and the passage of Old French system, which gives the priority to the identification of the theme, to Middle French, which takes into account the degrees of rhematic phrases. The diverse thematic progressions and, in particular, the emergence, during Middle French are then studied, progressions with derived themes, connected to the expression of the background. Changes which affect constituent order, in particular the change of status of V2 order, are then put in connection with textual evolutions.