The Marquis de Puységur, Artificial Somnambulism, and the Discovery of the Unconscious Mind presents the first full English translation of a foundational text in the history of psychodynamic thinking, and provides a contextual explanation of its contemporary significance.Written by Puységur in 1784, Memoirs to Serve the History and Establishment of Animal Magnetism describes the author's exploration and discovery of "artificial somnambulism," a state that reveals insights into the subconscious mind. Building on the healing techniques of Franz Anton Mesmer, Puységur kept detailed notes on his practice with patients, including their names, symptoms, and follow-up information, providing a unique insight into his process. The full text of this original publication is presented here, complemented by a historical introduction and editor's notes.The Marquis de Puységur, Artificial Somnambulism, and the Discovery of the Unconscious Mind will be of great interest to academics and scholars of psychoanalysis, psychotherapy, and the history of psychology, hypnosis, and mental health. It will also appeal to practicing clinicians.