antiquated adjective epithet of one given to lunacy

Lunatic is an old term that was used to refer to a person with a mental illness, or a mental disability. The term goes back to the Latin word lunaticus, which means ' of the moon', or moonstruck. It was also used in English law until about 1930, when it was replaced by "person of unsound mind". Starting 1959, English law speaks about "mental illness".

A lunatic in an asylum, engraving of 1828.


The horoscope of a "Lunatic" according to an astrologer who describes how the positions of the planets Saturn and Mars with respect to the moon are the cause of "diseases of the mind".[1]

The term "lunatic" was originally used to refer mainly to epilepsy and madness, as diseases thought to be caused by the moon.[2][3][4] The King James Version of the Bible records "lunatick" in the Gospel of Matthew which has been interpreted as a reference to epilepsy.[2] By the fourth and fifth centuries[needs to be explained], astrologers were commonly using the term to refer to neurological and psychiatric diseases.[2][5]Philosophers such as Aristotle and Pliny the Elder argued that the full moon induced insane individuals with bipolar disorder by providing light during nights which would otherwise have been dark, and affecting susceptible individuals through the well-known route of sleep deprivation.[6][needs to be explained] Until at least 1700, it was also a common belief that the moon influenced fevers, rheumatism, episodes of epilepsy and other diseases.[7]

Related pagesEdit


  1. Heydon, C. (1792). Astrology. The wisdom of Solomon in miniature, being a new doctrine of nativities, reduced to accuracy and certainty ... Also, a curious collection of nativities, never before published. London: printed for A. Hamilton. ISBN 9781170010471.
  2. 2.0 2.1 2.2 Riva, M. A.; Tremolizzo, L.; Spicci, M; Ferrarese, C; De Vito, G; Cesana, G. C.; Sironi, V. A. (January 2011). "The Disease of the Moon: The Linguistic and Pathological Evolution of the English Term "Lunatic"". Journal of the History of the Neurosciences. 20 (1): 65–73. doi:10.1080/0964704X.2010.481101. PMID 21253941. S2CID 5886130.
  3. J., J., T., Frey,Rotton,& Barry (1979). "The effects of the full moon on human behavior: Yet another failure to replicate". The Journal of Psychology: Interdisciplinary and Applied. 103 (2): 159–162.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  4. D.E., Campbell (1982). "Lunar–lunacy research: When enough is enough". Environment and Behavior. 14 (4): 418–424. doi:10.1177/0013916582144002. S2CID 144508020.
  5. Bunevicius, Genviliate, Pranas Deltuva, Tamasauskas, Adomas, Agne, Vytenis, Arimatas (2017). "The association between lunar phase and intracranial aneurysm rupture: Myth or reality? Own data and systematic review". BMC Neurology. 17 (99): 99. doi:10.1186/s12883-017-0879-1. PMC 5437543. PMID 28525979.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  6. The Moon and madness reconsidered Journal of Affective Disorders, June, 1999
  7. Harrison, Mark (2000). "From medical astrology to medical astronomy: sol-lunar and planetary theories of disease in British medicine, c. 1700–1850". The British Journal for the History of Science. 33 (1): 25–48. doi:10.1017/S0007087499003854. PMID 11624340. S2CID 22247498.