Sections Contest Property disposition Common types Other types Governing doctrines Insane delusion is the legal term of art in the common law tradition used to describe a false conception of reality that a testator of a will adheres to against all reason and evidence to the contrary.
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.
The probate court found that the father's mindset when he made the 1818 will was normal in all respects except toward his daughter.
[2] In the 1854 case Addington v. Wilson, the Indiana Supreme Court held that a testator who disinherited his daughters because he believed them to be witches 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; if these people's beliefs did not render them insane, neither did the testator's.