ACTIVE ILLUSION

A term introduced in or shortly before 1881 by the British psychologist James Sully (1842-1923) to denote a variant of what he calls illusions of interpretation (now known as * cognitive illusions). In Sully's reading, active illusions arise as a consequence of the false interpretation of a correctly perceived stimulus deriving from the extracorporeal environment, due to an improper excitement of the imagination. As Sully maintains, "A man experiences the illusion of seeing specters of familiar objects just after exciting his imagination over a ghost-story, because the mind is strongly predisposed to frame this kind of percept." Sully uses the term active illusion in opposition to the term *passive illusion. He illustrates the latter type of cognitive illusion as follows: "For example, we fall into the illusion of hearing two voices when our shout is echoed back, just because the second auditory impression irresistibly calls up the image of a second shouter." As he concludes, "In the one case the mind is comparatively passive; in the other it is active, energetically reacting on the impression, and impatiently anticipating the result of the normal process of preperception. Hence I shall, for brevity's sake, commonly speak of them as Passive and Active Illusions."

Sully, J. (1881).Illusions: A psychological study. New York, NY: Humboldt Publishing Company.