Based on self-experimentation with the healers of the Peruvian Alta Amazonia, the author presents the framework and conditions of the visionary "production" in traditional therapy, through the use of it ayahuasca, liana with psychotropic effects. Trying to find some constants that will allow to characterize the visions that follow the ingestion of Ayahuasca, he then proposes a reflection on the teachings achieved by these practices and defines the criteria of validity which he says make these changes to states of consciousness a subject of study worthy, particularly from the therapeutic point of view.