A general blanket term, proposed by B. P. Wiesner and seconded by R. H. Thouless (1942), and used either as a noun or adjective to identify paranormal processes and paranormal causation; the two main categories of psi are psi-gamma (paranormal cognition; extrasensory perception) and psi-kappa (paranormal action; psychokinesis), although the purpose of the term “psi” is to suggest that they might simply be different aspects of a single process, rather than
distinct and essentially different processes. Strictly speaking “psi” also applies to survival of death. Some thinkers prefer to use “psi” as a purely descriptive term for anomalous outcomes, as suggested by Palmer (1986, p. l39), who defines it as “a correspondence between the cognitive or physiological activity of an organism and events in its external environment that is anomalous with respect to generally accepted basic limiting principles of nature such as those articulated by C. D. Broad.” [From the Greek, psi, twenty-third letter of the Greek alphabet; from the Greek psyche, “mind, soul”]