Definition of hallucination

The word "hallucination" comes from the Latin word "hallucinare", which means "to wander" or "make to wander". This term was used by the medieval physician Galen (AD 129-200) to describe a disturbed state of the senses, in which an individual perceives something that does not actually exist in the external world. The term gained its modern meaning in the 19th century, with the work of French psychiatrist Joseph Babinski (1857-1932). Babinski used "hallucination" to describe a mental disturbance in which individuals saw or heard things that were not real, often attributed to pathological conditions such as brain damage, neurological disorders, or psychological conditions such as schizophrenia. Since then, the meaning of the word "hallucination" has become more specific, denoting a false or distorted perception in one or more of the five senses, without any external stimulus. Today it is primarily used in the context of psychiatry and psychology to describe mental phenomena that are subjective and often illusory, but not necessarily pathological or indicative of a psychiatric disorder.