Middle French precognition foreknowledge (1488 or earlier; French précognition) or its etymon post-classical Latin praecognition-, praecognitio previous knowledge (4th cent.) < classical Latin praecognit-, past participial stem of praecognōscere to know beforehand
In parapsychology, precognition (from the Latin præ-, “before,” + cognitio, “acquiring knowledge”), also called future sight, is a type of extrasensory perception that would involve the acquisition or effect of future information that cannot be deduced from presently available and normally acquired sense-based information or laws of physics and/or nature. A premonition (from the Latin praemonēre) and a presentiment are information about future events that is perceived as emotion.
As with other forms of extrasensory perception, the existence of precognition is not accepted, as other than a purely psychological process, by the mainstream scientific community because no replicable demonstration has ever been achieved. Scientific investigation of extrasensory perception (ESP) is complicated by the definition which implies that the phenomena go against established principles of science. Specifically, precognition would violate the principle that an effect cannot occur before its cause. However, there are established biases, affecting human memory and judgment of probability, that create convincing but false impressions of precognition.
Many of the "psychic experiences" that are volunteered to parapsychologists by the general population involve apparent precognition. In one review of a U.S. case collection, submitted to Duke University's Parapsychology Laboratory, 75% of 1777 dream-based experiences were of an ostensibly precognitive type, as were 60% of 1513 wakeful experiences. A similar pattern was identified for a separate collection of 157 cases experienced by children; here, the largest category of experiences was again of precognitive dreams (52%), followed by precognitive intuitions (52%). A German case collection produced a similar figure: 52% of 1,000 cases were of the apparently precognitive type. A British study of 300 volunteered cases showed 34% to be apparently precognitive.
Louisa Rhine at the Parapsychology Laboratory at Duke University compiled the best-known and largest body of dream evidence. Dr. Rhine collected over 7000 accounts of ESP experiences. The majority of these accounts were dream related and were seemingly precognitive in nature. The material for this work was collected by advertisements in various well-known popular media.
David Ryback, a psychologist in Atlanta, used a questionnaire survey approach to investigate precognitive dreaming in college students. His survey of over 433 participants showed that 290 or 66.9 percent reported some form of paranormal dream. He rejected many of these claims and reached a conclusion that 8.8 percent of the population was having actual precognitive dreams.
An early inquiry into this phenomenon was done by Aristotle in his On Divination in Sleep. His criticism of these claims appeals to the fact that "the sender of such dreams should be God", and "the fact that those to whom he sends them are not the best and wisest, but merely commonplace persons." Thus: "Most [so-called prophetic] dreams are, however, to be classed as mere coincidences...", here "coincidence" being defined by Aristotle as that which does not take "place according to a universal or general rule" and referring to things which are not of themselves by necessity causally connected, his example being taking a walk during an eclipse, neither the walk nor the eclipse being apparently causally connected and so only by "coincidence" do they occur simultaneously.
Other researchers in this area are more guarded in their reports on the value or use of dreams. In his book The Interpretation of Dreams, first published at the end of the [http://en.wikipedia.org/wiki/19th_century 19th century, Sigmund Freud argued that the foundation of all dream content is the fulfillment of wishes, conscious or not and devoid of psychic content. In his discussions with Carl Jung, he referred to parapsychology and precognition as “nonsensical.”