Joseph Ennemoser (1787-1854) was born in Tyrol and, after fighting in the Tyrolean rebellion and the Napoleonic wars, qualified as a physician in Berlin. He later became professor at the recently founded University of Bonn, and eventually opened a successful medical practice in Munich. Ennemoser was a leading figure in the then highly fashionable field of ‘animal magnetism’ (popularised by Mesmer in the later eighteenth century) and hypnosis, and his emphasis on the connection between the mind and physical health foreshadowed Freud’s development of psychoanalysis. The holistic views of the mesmerists incorporated ideas both from natural philosophy and from German Romanticism, and Ennemoser and his contemporaries wrestled with the problem of integrating materialist and mystical viewpoints. In this 1842 publication, Ennemoser analyses the relationship between ‘animal magnetism’, nature and religion, focusing on phenomena including visions, their physiological and psychological explanations, and the application and effects of ‘magnetic’ treatments.