Abstract
In the early nineteenth century, investigations into the nature of psychic/spiritual phenomena, like trances and the supposed acquisition of information unattainable using normal sensory channels, prompted much debate in the scientific arena. This article discusses the main explanations offered by the researchers of psychic phenomena reported between 1811 and 1860, concentrating on the two main movements in the period: magnetic somnambulism and modern spiritualism. While the investigations of these phenomena gave rise to multiple theories, they did not yield any consensus. However, they did have implications for the understanding of the mind and its disorders, especially in the areas of the unconscious and dissociation, constituting an important part of the history of psychology and psychiatry.
somnambulism; trance; mesmerism; spiritual mediumship