- Also referred to as incubo, night hag, nightmare, incubus experience, and familiar. The term incubus is Latin for night hag or nightmare. It comes from the verb incubare, which means to lie upon. The term is used in demonology to denote an angel that has fallen, and in the guise of a man seeks sexual intercourse with mortal women while they are asleep. A fallen angel in the guise of a woman that likewise seeks sexual intercourse with mortal men is called a " succubus (i.e. a demon collecting semen by causing nocturnal ejaculations). In the past many "nightmares and sometimes even " daymares were attributed to the interference of incubi, although strictly speaking it is more likely that the nocturnal experiences attributed to incubi were night terrors rather than nightmares. The belief in incubi is thought to have its roots in ancient times. It has been suggested that the concept itself developed out of pagan speculations about the commerce of gods with people. During the Middle Ages, the belief in incubi became assimilated with Christianity. During that time, when associated with an alleged witch or sorcerer, incubi were known as 'familiars'. Throughout the ages, the incubus phenomenon has been surrounded by many different hypotheses and speculations. As the French alienist Alexandre Jacques François Brierre de Boismont (1797-1881) wrote in 1845, "In the present day the term incubus is usually applied to the nightmare, but formerly it referred to imaginary fiends or spectres, to whom strange powers are attributed by the writers on demoniacal agency. Many noble families were supposed to have their origin from the connexion of incubi with females, as in the well-known instance of Robert of Normandy, called le Diable. The succubus was a similar fiend of the female sex." As noted by the German classical scholar Wilhelm Heinrich Roscher (1845-1923), a certain analogy would seem to exist between the incubus of classical and medieval times, and the " Mar of Germanic superstition. The American psychopharmacologist Ronald K. Siegel, who is himself familiar with incubus attacks, questions the alleged sexual nature of the experience. In or shortly before 2001 the term incubus, stripped of its metaphysical connotations, was reintroduced by the Canadian psychologist and sleep researcher James Allan Cheyne. He uses the term incubus to denote a major cluster of "hallucinoid experiences (i.e. somatosensory phenomena which co-occur with "hypnagogic or " hypnopompic hallucinations, but which are not themselves hallucinations). They occur during the stages of " sleep paralysis and are similar to those which in the classical literature are attributed to the presence or actions of an incubus. Symptoms of this cluster include bodily pressure (typically on the breast), breathing difficulties, pain, and associations with impending death. Cheyne proposes that the term incubus be used in opposition to the terms " intruder and " illusory movement experiences, which constitute two additional clusters of hallucinoid experiences.ReferencesBrierre de Boismont, A. (1859). On hallucinations. A history and explanation of apparitions, visions, dreams, ecstasy, magnetism, and somnambulism. Translated by Hulme, R.T. London: Henry Renshaw.Cheyne, J.A. (2001). The ominous numinous. Sensed presence and 'other' hallucinations. Journal of Consciousness Studies, 8, 133-150.Robbins, R.H. (1959). The encyclopaedia of witchcraft and demonology. London: Peter Nevill.Siegel, R.K. (1992). Fire in the brain. Clinical tales of hallucination. New York, NY: Dutton.
Dictionary of Hallucinations. J.D. Blom. 2010.