Between angelic visions and shamanistic trance: the Witches’ Sabbath in the Formicarius of Nider. The Formicarius of Johannes Nider (1380-1438), finished around 1435, describes saints and heretics, visions, revelations, phenomena of possession and simulation, extraordinary virtues and mortal sins, miraculous workings and the deeds of magicians and sorcerers. To explain the extraordinary significance of religious trance in these stories, we propose to examine the hypothesis of a correlation between shamanism, religious ecstasy and the emergence of the beliefs in diabolic witchcraft. Following the very original conceptual scheme of Nider, who juxtaposes visions of heavenly and diabolic origin, we analyse successively the relationship between shamanism and visionary sainthood at the end of the Middle Ages, then between the former and the witches’ sabbath, to able to show, finally, in what ways could the trance be considered as a common point between the saint and the witch, who constitute a binary system with a shaky polarity in the 15th century.