- delusion
- delusion, illusionoverlap in meaning because both are to do with things wrongly believed or thought for various reasons. There is, however, a distinguishing principle: a delusion is a wrong belief regarded from the point of view of the person holding it (and has special uses in psychiatry, as in delusions of grandeur), whereas an illusion is a wrong belief or impression regarded externally. Delusion, unlike illusion, has a corresponding verb, delude, and the action of this verb is sometimes implicit in the choice between delusion and illusion. The following examples will help to clarify these points: (delusion)
• He suffered from the delusion that everything smelled of cats —Arthur Koestler, 1947
• That was the way delusions started, thinking there was anti-Jewish feeling when there wasn't —P. H. Newby, 1968
• Amorous delusions concerning…a lecherously attentive neighbour and her kindly but pre-occupied husband —Daily Telegraph, 1970
• Ed continues to labour under the delusion that I'm a Liverpool fan —Guardian Unlimited, 2003
• In the world as we know it…freedom is largely an illusion —J. M. Roberts, 1975
• The illusion must be maintained that this was a purely Polish debate with no intrusion being made by the Soviet Union —J. A. Mitchener, 1983
• Alfred Crowther loved his first-born child, but he had no illusions about him —B. T. Bradford, 1986.
Modern English usage. 2014.