The term true hallucination has a variety of meanings and connotations. First, it is used to remove any possible doubt concerning the status of a given percept as a hallucination. In this context, the term is used by the French psychiatrist Claude-François Michéa (1815-1882) in opposition to the term "false hallucination (which may refer to a " dream or " incomplete hallucination, for example). True hallucinations are also referred to as genuine hallucinations, veridical hallucinations, and hallucinations proper. Second, the term true hallucination has sometimes been used in a seemingly paradoxical sense. For example, the French critic and historian Hippolyte Taine (1828-1893) employs the term to denote a regular sense perception. Starting from the premise that sense perceptions are based on mind-independent objects or stimuli in the external environment, whereas hallucinations derive their contents from endogenously generated perceptual information, Taine argues that "instead of saying that an hallucination is a false exterior percept, one should say that the external percept is a true hallucination." A third meaning of the term true hallucinations stems from parapsychology, where it is sometimes used as a synonym for "veridical hallucination and "coincidental hallucination. Although the exact meaning of these latter terms tends to vary somewhat from author to author, they all refer to percepts that have a bearing on actual people (or objects, or situations) from which the " hallucinator is separated in place and/or time. Despite the use of the adjective 'true', for some parapsychologists there is still a certain connotation of subjectivity or morbidity connected with the word hallucination. In an attempt to do away with that connotation, it has been proposed to replace the term true hallucination with the term " monition.
References
Michéa, C.-F. (1871). Du délire des sensations. Paris Labé.
Myers, F.W.H. (1903). Human personality and its survival of bodily death. Volume I. London: Longmans, Green, and Co.
Taine, H. (1870). De l'intelligence. Tome 2. Paris: Librairie Hachette et Cie.
Dictionary of Hallucinations. J.D. Blom. 2010.