born May 23, 1734, Iznang, Swabia
died March 5, 1815, Meersburg
German physician.
After studying medicine at the University of Vienna, he developed his theory of "animal magnetism," which held that an invisible fluid in the body acted according to the laws of magnetism and that disease was caused by obstacles to the free circulation of this fluid. In Mesmer's view, harmony could be restored by inducing "crises" (trance states often ending in delirium or convulsions). In the 1770s he carried out dramatic demonstrations of his ability to "mesmerize" his patients using magnetized objects. Accused by Viennese physicians of fraud, he left Austria and settled in Paris (1778), where he also came under fire from the medical establishment. Though his theories were eventually discredited, his ability to induce trance states in his patients made him the forerunner of the modern use of hypnosis .