ESQUIROL'S DEFINITION OF HALLUCINATIONS

   In 1845 the French alienist Jean-Etienne Dominique Esquirol (1772-1840) defined hallucinations as follows. "A person is said to labor under a hallucination, or to be a visionary, who has a thorough conviction of the perception of a sensation, when no external object, suited to excite this sensation, has impressed the senses."

   References

   Esquirol, J.-E.D. (1965). Mental maladies. A treatise on insanity. A facsimile ofthe English edition of 1845. Translated by Hunt, E.K. New York, NY: Hafner Publishing Company.