English summary: Skillfully expressing his realization of emptiness, Dogen (1200-1253) tears to pieces chapter after chapter the concept of Buddha-nature. For him, the buddha-nature is not something human beings can awaken to. It is not a nature as such. It is there-is without anything missing. The nature is not 'from' or 'of'Buddha; it is always and already buddha, even prior to heaven and earth. Emptiness is testified when the body and mind sitting in perfect concen-tration cast off attachments. Dogen's emptiness is the integral emptiness of Nagarjuna. Dogen's wisdom is the irascible wisdom of Gozanze. French description: Ce texte est la transcription par Ejo d'un discours que Dogen prononca dans le temple de Koshohorin-ji a Fukakusa, pres de Kyoto, en 1241. Le maitre zen y rejette le dogme de la nature du Bouddha, nature qui permettrait a ceux qui en sont pourvus d'atteindre l'eveil. Son vacuisme integral s'inscrit dans la droite ligne de Nagarjuna, fondateur du bouddhisme du Milieu, et de son successeur Aryadeva.