The Limits of Influence is a detailed examination and defense of the evidence for largescale-psychokinesis (PK). It examines the reasons why experimental evidence has not, and perhaps cannot, convince most skeptics that PK is genuine, and it considers why traditional experimental procedures are important to reveal interesting facts about the phenomena. It then examines why PK does not pose a clear threat to the very fabric of science, as many have proposed. The major skeptical challenges to taking large-scale PK seriously and the reason why those challenges are all unsatisfactory are considered. The evidence examined most closely is the turn-of-the-century evidence for physical mediumship, with special attention given to the cases of D.D. Home and Eusapio Palladino. The author compares and evaluates the leading theories of apparitions and considers the extent to which the evidence for collective apparitions can be interpreted as a further type of psychokinetic phenomenon. Finally, the claim that PK (and psychic functioning generally) might occur in refined and extensive forms is considered. It argues that this claim is not as outlandish as many have maintained and that we might have to accept something like the 'magical' world view associated with so-called 'primitive' societies.
