It was as a branch of ‘genetic criticism’ that a genetics of the theatre first established itself in France as a scientific field of study. Applied to literature alone in the first place, it has since then gradually widened its scope of investigation. Taking Marguerite Duras's first play, Le Square (1956) as an example, this essay aims to demonstrate the main effects of such a disciplinary gestation on the ‘French’ approach to the creative processes as regards the theatre. On the one hand, the existence of well-tried methodological procedures for the study of manuscripts permits both a dynamic re-examination of dramatic works and a criticism of the myths which often surround them. On the other, apprehending the different textual materials and the other kinds of genetic documents produced around the stage according to a methodologically coherent manner reveals the constant interdependence of techniques and arts, and the need to improve models constructed for altogether different studies.