Insane delusion is the

legal Law is a set of rules that are created and are law enforcement, enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. ...

term of art Jargon is the specialized terminology associated with a particular field or area of activity. Jargon is normally employed in a particular communicative context and may not be well understood outside that context. The context is usually a particu ...

in the

common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omnipres ...

tradition used to describe a false conception of reality that a

testator A testator () is a person who has written and executed a last will and testament that is in effect at the time of their death. It is any "person who makes a will."Gordon Brown, ''Administration of Wills, Trusts, and Estates'', 3d ed. (2003), p. 556 ...

of a will adheres to against all reason and evidence to the contrary. A will made by a testator suffering from an insane delusion that affects the provisions made in the will may fail in whole or in part. Only the portion of the will caused by the insane delusion fails, including potentially the entire will.

Will contest A will contest, in the law of property, is a formal objection raised against the validity of a will, based on the contention that the will does not reflect the actual intent of the testator (the party who made the will) or that the will is otherwis ...

s often involve claims that the testator was suffering from an insane delusion. An insane delusion is distinct from

testamentary capacity In the common law tradition, testamentary capacity is the legal term of art used to describe a person's legal and mental ability to make or alter a valid will. This concept has also been called sound mind and memory or disposing mind and memory. ...

. A testator might be suffering from an insane delusion but otherwise possess the requisite capacity to make a will. Similarly, an insane delusion is distinct from a mere mistake. If suffering from an insane delusion, a testator is not subject to change his or her mind regarding the delusion if presented with contrary evidence, whereas a mistake is capable of being corrected if the testator is told the truth. Additionally, while an insane delusion may cause portions of a will to fail, most courts will not reform or invalidate a will because of a mistake unless it was the result of fraud.

Origin

The insane delusion concept was created in the 1826 British case ''Dew v. Clark''. In that case, a father believed that his daughter was "the devil incarnate" and disinherited her in his will of 1818. After her father's death, evidence presented by the daughter showed that she was well known for her good disposition and that her father had falsely told others that he lavished his daughter with praise and wealth. The probate court found that the father's mindset when he made the 1818 will was normal in all respects except toward his daughter. The court found that his thoughts about her, "did and could only proceed from, and be founded in, insanity," a "partial insanity" that only extended to his thoughts about his daughter and caused him to disinherit her. The court said that this delusion caused the will to fail.

Examples

In the 1854 cas
''Addington v. Wilson''
the Indiana Supreme Court held that a testator who disinherited his daughters because he believed them to be

witch Witchcraft traditionally means the use of magic or supernatural powers to harm others. A practitioner is a witch. In medieval and early modern Europe, where the term originated, accused witches were usually women who were believed to have us ...

es was not for that reason alone so insane as to deem him incapable of making a valid will. The court justified its decision by pointing to distinguished jurists and religious figures who affirmed the possibility of

witchcraft Witchcraft traditionally means the use of magic or supernatural powers to harm others. A practitioner is a witch. In medieval and early modern Europe, where the term originated, accused witches were usually women who were believed to have ...

; if these people's beliefs did not render them insane, neither did the testator's. I
''In re Robertson's Estate''
(1948), the Supreme Court of Oklahoma held that a testator who declared that he had "no children" and "no deceased children" in his will, when he actually had two living children, was suffering from an insane delusion, as the testator had "no rational basis whatsoever" to declare that he had no children.''In re Robertson's Estate'', 189 P.2d 615 (Okla. 1948)

References

{{Reflist Wills and trusts Elder law Common law Legal concepts