For centuries both primitive and sophisticated societies have been spellbound by persons who claim to have 'psychic' power. Those who present a case for the existence of extrasensory perception (ESP) - mediums, spiritualists, telepaths, clairvoyants, psychokinetics, and others - insist that their unique abilities stand outside the realm of conventional scientific evaluation; that parapsychology offers new hope for understanding the richness and diversity of the human mind and its relationship to the world. In fact, much has been done in recent years in an attempt to convince the scientific community that such phenomena are legitimate and credible. What challenges do these parapsychological claims pose to science? What support is given for the existence of these phenomena? Have the advocates of ESP established their case? In this revised and updated edition of his powerful volume "ESP and Parapsychology: A Re-evaluation", C.E.M. Hansel, one of the first internationally known scholars to evaluate the evidence for ESP, returns once more to the trenches to reassess, rethink, and reconsider some of the major battlefields of this ongoing debate. Undaunted by persistent claims for newly discovered psychical energies and capacities, Hansel remains dedicated to the view that if ESP is to be scientifically established there must be demonstrable proof in the form of replicable experiments. This fascinating volume recounts the scientific community's efforts to provide, test, and analyze such evidence, while at the same time seeking to expose the confusion, trickery, and deception that has permeated the search for psychic power.