Multiple personality and hypnosis: the first one hundred years

The Enlightenment brought with it a greater scientific interest in and attention to a wider range of human behavior. In 1789, there emerged during the French Revolution a case of what would be today called multiple personality disorder which came under the care of a local physician, Dr. Eberhard Gmelin. Gmelin had only recently become interested in mesmerism and tried this procedure with this patient. So started an ongoing and gradually increasing exploration of the role of hypnosis in multiple personalities. This paper contributes to the historical background of such psychodynamic concepts as dissociation, splitting, repression, consciousness, subconscious, and unconscious.