Parapsychology
As a scientist, Richet was positive about a physical explanation for paranormal phenomena. He wrote: "It has been shown that as regards subjective metapsychics the simplest and most rational explanation is to suppose the existence of a faculty of supernormal cognition … setting in motion the human intelligence by certain vibrations that do not move the normal senses."
He later wrote about a “sixth sense,” an ability to perceive the hypothetical vibrations; he discussed this theory in his book Our Sixth Sense (1928).
He also believed that some mediumship could be explained physically due to the external projection of a material substance (ectoplasm) from the body of the medium.
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