Book excerpt: The power of the mind to influence the physical world has long been debated, debunked, studied for military applications, and used in science fiction. This historical and theoretical study of mind-matter interaction, or MMI, explores the phenomena of levitation, stigmata, inedia, paranormal activity, bilocation, fire immunity, luminosity, and the teleportation of matter. The results of more than a century of formal experimental research are discussed, as are resultant training techniques, theories, and controlled experiments used to test or bolster psychokinetic abilities.