Psychical Research: The Science of the Super-Normal

The History and Theory of Vitalism

Geschichte Des Vitalismus

The Science and Philosophy of the Organism

The History & Theory of Vitalism. Authorised Translation by C.K. Ogden. REV. and in Part Re-Written for the English Ed. by the Author

Haunted People: The Story of the Poltergeist Down the Centuries

The Unknown

Science and Personality

Spiritism and Religion. "can You Talk to the Dead?"

The Art of Dreaming