Abstract: In Le Cahier vert, the clouds bear witness to the author’s attention to the surrounding environment and to nature, but they also spark reflection on creation, the process of which they metaphorically sketch out. It is as if Maurice de Guérin gradually discovered the hermeneutic function of a cloud: it becomes the actor in a painting that offers itself up as a work in its own right and serves as a tool to decipher the geography of the soul.