Also known as hallucinogen, hallucinogenic drug, hallucinogenic substance, magicum, phanerothyme, pseudohallucinogen, illusinogen, mysticomimetic, "psychedelic, psychedelic drug, psychedelic substance, psychotic, "psychotomimetic, and phantasticum. The term eideticum comes from the Greek noun eidos, which means appearance or idea. The Greek-German neologism Eidetikum was introduced in or shortly before 1941 by the German psychologist Willy Hugo Hellpach (1877-1955), a former student of Emil Kraepelin (1856-1926). The term eideticum and its equivalents are used more or less interchangeably to denote a group of chemical substances which in relatively high doses have the potential to alter consciousness, and to evoke phenomena such as hallucinations, " illusions, "sensory distortions, "delirium, loss of contact with reality, and occasionally coma and death. In 1979 the term " entheogen was proposed as an alternative for these terms, in an effort to reinstate the original spiritual connotations of substances like these within "mysticism and shamanism. For a more detailed account of this group of substances, see the entry Hallucinogen.
References
Hellpach, W. (1941). Funktionelle Differenzierung psychischer Stimulantien. Deutsche Medizinische Wochenschrift, 67, 1358.
Stoll, A. (1947). Lysergsäurediäthylamid, ein Phantastikum aus der Mutterkorngruppe. Schweizer Archiv für Neurologie, 60, 279-323.
Dictionary of Hallucinations. J.D. Blom. 2010.