René Allendy was one of the first French psychoanalysts. He was also a homeopath. A text by him on the "medicine of the imponderables" demonstrates his proximity to esoteric theories. The objective of this article is to illustrate a cultural misunderstanding at the time of the introduction of psychoanalysis in France, when it met up with a Gnostic and Illuminist heritage that was still very much alive. This initial confusion between the Freudian approach, which was in keeping with the thinking of the Lumières, and a certain obscurantism, explains perhaps some of the resistance as well as some of the subsequent deviations of psychoanalysis in France.