Illusion

A species of mania, in which the sensibility of the nervous system is altered, excited, weakened, or perverted. The patient is deceived by the false appearance of things, and his reason is not sufficiently active and powerful to correct the error; and this last particular is what distinguishes the sane from the insane. Illusions are not unfrequent in a state of health, but reason corrects the errors, and dissipates them. A square tower, seen from a distance, may appear round, but, on approaching it, the error is corrected. A distant mountain may be taken for a cloud, but as we approach we discover the truth. tion and a closer examination soon destroy this illusion. An insane individual is mistaken on the qualities, connections, and causes of the impressions he actually receives, and he forms wrong judgments as to his internal and external sensations; and his reason does i. it correct the error. 1 Beck, Med. Jur. 538; Esquirol, tom. 1, p. 202; Diet, des Sciences Medicales, "Hallucination." See "Hallucination."

A term loosely applied to both delusions and hallucinations, but more frequently to the latter fq. v.J. By some it is restricted to the perception of objects in characters which they do not possess. The patient is deceived by the false appearance of things, and his reason Is not sufficiently active and powerful to correct the error; and this last particular is what distinguishes the sane from the insane. Illusions are not unfrequent in a state of health, but reason corrects the errors and dissipates them. A square tower seen from a distance may appear round, but on approaching it the error is corrected. A distant mountain may be taken for a cloud, but, as we approach we discover the truth. To a person in the cabin of a vessel under sail, the shore appears to move; but reflection and a closer examination soon destroy this illusion. An insane individual is mistaken in the qualities, connections, and causes of the impressions he actually receives, and he forms wrong judgments as to his internal and external sensations; and his reason does not correct the error; 1 Beck. Med. Jur. 638; Tayl. Med. Jur. 683; Bsquirol, Maladies Mentales, pr6m. partie, ill, tome 1, p. 202; Diet, dea Sciences M6di^ cales, Hallucination, tome 20, p. 64. See Hallucination; Insanity.

In medical jurisprudence. An imige or impression in the mind, excited by some external object addressing itself to the senses, but which, instead of correspending with the reality, is perverted, distoried, or wholly mistaken,

See Insanity, Compare Delusion.