- The term vision comes from the Latin noun visio, which means 'sight'. It has various meanings and connotations, including the sense ofsight, a mental image produced by the imagination, and a * visual hallucination (with or without the con-notationofa*mystical experience). Visions - in the sense of visual hallucinations - were divided by the British scientist Sir Francis Galton (18221911) into five orders of phenomena. To Galton the lowest order of visions are the *number forms, or * number form synaesthesias, as they are known today, followed by the group of *colour associations (as in * colour hearing, another type of synesthaesia). Galton's third order of visions consists of visualized pictures arising in association with words. His fourth order consists of * phantasmagoria, a notion closely resembling our present-day class of * hypnagogic hallucinations, and the fifth of visual hallucinations proper.Galton suggested that the propensity to experience visions is strongly hereditary in nature: "I have found that the peculiarities of visualisation, such as the tendency to see Number-Forms, and the still rarer tendency to associate colour with sound, is strongly hereditary, and I should infer, what facts seem to confirm, that the tendency to be a seer of visions is equally so." He also suspected that the propensity to hallucinate is actually quite common in the general population and subject to the encouragement and discouragement by important others: "My interpretation of the matter, to a certain extent, is this - That the visionary tendency is much more common among sane people than is generally suspected. In early life, it seems to be a hard lesson to an imaginative child to distinguish between the real and visionary world. If the fantasies are habitually laughed at and otherwise discouraged, the child soon acquires the power of distinguishing them; any incongruity or nonconformity is quickly noted, the visions are found out and discredited, and are no further attended to. In this way the natural tendency to see them is blunted by repression. Therefore, when popular opinion is of a matter-of-fact kind, the seers of visions keep quiet... But let the tide of opinion change and grow favourable to supernaturalism, then the seers of visions come to the front... We need not suppose that a faculty previously non-existent has been suddenly evoked, but that a faculty long-smothered by many in secret has been suddenly allowed the freedom to express itself, and to run into extravagance owing to the removal of reasonable safeguards." For further details, see the entries Visual hallucination and Visual illusion.ReferencesClarke, E.H., Holmes, O.W. (1878). Visions: A study of false sight (pseudopia). Boston, MA: Houghton, Osgood & Company.Galton, F. (1883). Inquiries into human faculty and its development. London: J.M. Dent & Sons.Müller, J. (1826). Ueber die phantastischen Gesichtserscheinungen. Koblenz: Hölscher.
Dictionary of Hallucinations. J.D. Blom. 2010.