Parapsychology

Tales of dreams that come true, ‘mind over matter’ and other such oddities are both familiar and old. Parapsychology investigates such things, attempting to use scientific and, especially, experimental methods to investigate whether and in what circumstances humans can glean information without using ordinary perceptual means (that is, by extrasensory perception or ESP) or can alter the physical environment simply by willing it (that is, by psychokinesis). Such phenomena, if they exist, are often grouped under the heading psi(-phenomena).

It is sometimes claimed that parapsychology presents a challenge to physicalism. However, ostensible psi-phenomena are known through their physical effects and are studied within parapsychology by ordinary scientific methods. In fact, models intended to explain psi-phenomena by known physical processes have been seriously discussed within parapsychology. In any case, parapsychology alone could not show that psi-phenomena have no physical explanation; that is a judgment for physics itself. More important, physicalism is a very broad doctrine that should not simply be equated with the requirement that everything be explained within physics. It is very unclear what we would gain by denying that psi-phenomena are physical.