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See: artifice, bad faith, deception, error, fallacy, false pretense, figment, hoax, insanity, lunacy, phantom, ruse, sham

DELUSION, med. jurisp. A diseased state of the mind, in which persons believe things to exist, which exist only, or in the degree they are conceived of only in their own imaginations, with a persuasion so fixed and firm, that neither evidence nor argument can convince them to the contrary.
     2. The individual is, of course, insane. For example, should a parent unjustly persist without the least ground in attributing to his daughter a course of vice, and use her with uniform unkindness, there not being the slightest pretence or color of reason for the supposition, a just inference of insanity, or delusion, would arise in the minds of a jury: because a supposition long entertained and persisted in, after argument to the contrary, and against the natural affections of a parent, suggests that he must labor under some morbid mental delusion. 3 Addams' R. 90, 91; Id. 180; Hagg. R. 27 and see Dr. Connolly's Inquiry into Insanity, 384; Ray, Med. Jur. Prel. Views., Sec. 20, p. 41, and Sec. 22, p. 47; 3 Addams, R. 79; 1 Litt. R. 371 Annales d'Hygiene Publique, tom. 3, p. 370; 8 Watts, 70; 13 Ves. 89; 1 Pow. Dev. by Jarman, 130, note Shelf. on Lun. 296; 2 Bouv. Inst. n. 2104-10.

References in periodicals archive ?
After the last 5 years of shared delusion, and acting to protect themselves, the patient and father covered all the windows with towels and paper.
For cases of primary delusional infestation, the goal generally is to decrease the patient's preoccupation with the delusion and to improve social and occupational functions.
Summary: Delusion has always been a central topic for psychiatric research with regard to its etiology, pathogenesis, diagnosis, treatment, and forensic relevance.
She only took antiepileptics as aforementioned with antipsychotics at that time, even though her delusion of jealousy persisted.
In the pantheon of fascinating psychological disorders, the Cotard Delusion is one of the most bizarre you can imagine -- and it is not even one of those hip and fashionable ones usually associated with music celebrities or dieting.
The author concludes that if we really want relationships which overcome the problems of power and gender polarisation, we must see romantic love for what it is--a delusion which can implicate lovers in the repeated destruction of their own happiness.
Whereas the foundation of the delusion is brain pathology, the content of the delusion is colored by the affected person's cultural and religious background.
Cotard's Syndrome (CS) is a rare clinical event, characterized by negation delusion (or nihilist), generally regarding the body (frequently the patient believes that he or she does not have one or more organs) or regarding the existence (the individual judges that himself or everybody in the world is dead or reduced to nothing, being able to judge himself a zombie), but also concerning concepts/conditions [1] (such as a CS case described in which a woman was sure about not being pregnant, despite of obvious evidences [2]).
In the case of In re Estate of Berg the South Dakota Supreme Court, in 2010, held that an individual possessed testamentary capacity even where he suffered a static lifelong delusion about the identity of his father and was unable to articulate an accurate estimate of his net worth.
According to the conditioning theory, patients are prone to create delusion due to their mental condition.
The key feature of our history in the last 55 years has been the culture of acute delusion.
Solving the Strategy Delusion is said to present the reader with a practical understanding of why strategic change consistently fails and how to resolve it.