Ideoplasty is in Mediumship, a theory that holds that the beliefs and expectations of sitters or experimenters telepathically influence the Medium, who in turn produces the phenomena that support the desired theory. Ideoplasty is also described as the theory that the DREAMS of an entranced medium are embodied by a process that incorporates suggestions from the sitters as an important formative element. Thus, ideoplasty was behind the formation of Ectoplasm and Materialization.

Ideoplasty is similar to the “experimenter effect” observed in Psychical Research—an experimenter’s expectations unconsciously influence the results of an experiment.

Gustave Geley favoured ideoplasty, calling it “modeling living matter by ideas.” Baron Albert von Schrenck-Notzing agreed with Geley. Both men rejected Spiritualism.

In 1967, Maxwell Cade, a writer on UFOs and paranormal topics, modifi ed ideoplasty into “the reflected thought image” that phenomena match sitters’ expectations. Cade noted that the process would require a great deal of Extrasensory Perception. Rupert Sheldrake’s theory of morphogenetic fields, organisms sharing experiences regardless of time or distance, can be related to ideoplasty.

In the 1970s, Dr. Morton Schatzman, a London psychiatrist, taught a patient to subject her hallucinations to voluntary control. The woman was able to project at will realistic, lifelike images that remained until she deliberately dissolved them. The images were like lucid dreams, but did not intercept light. However, only the patient could see and converse with the images.



  • Cassirer, Manfred. Medium on Trial: The Story of Helen Duncan and The Witchcraft Act. Standstead, England: PN Publishing, 1996.
  • Pilkington, Rosemarie. Men and Women of Parapsychology: Personal Refl ections. Jefferson, N.C.: McFarland, 1987.


The Encyclopedia of Ghosts and Spirits – Written by Rosemary Ellen Guiley – September 1, 2007