M'Naghten rule

rule (rldbomacl) a statement of conditions commonly observed in a given situation, or of a prescribed procedure to obtain a given result.

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Durham rule  a definition of criminal responsibility from a federal appeals court case, Durham vs. United States, holding that “an accused is not criminally responsible if his unlawful act was the product of mental disease or mental defect.” In 1972 the same court reversed itself and adopted the American Law Institute Formulation.

M'Naghten rule  a definition of criminal responsibility formulated in 1843 by English judges questioned by the House of Lords as a result of the acquittal of Daniel M'Naghten on grounds of insanity. It holds that “to establish a defense on the ground of insanity, it must be clearly proved that at the time of committing the act the party accused was laboring under such a defect of reason from disease of the mind as not to know the nature and quality of the act he was doing, or, if he did know it, that he did not know that what he was doing was wrong.”

Nägele's rule  (for predicting day of labor) subtract three months from the first day of the last menstruation and add seven days.

rule of nines  a method of estimating the extent of body surface that has been burned in an adult, dividing the body into sections of 9 per cent or multiples of 9 per cent.

Rule of nines.

van't Hoff's rule  the velocity of chemical reactions is increased twofold or more for each rise of 10°C in temperature; generally true only when temperatures approximate those normal for the reaction.

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M'Nagh·ten rule (mk-nôtn)

n.

An 1843 English rule used as a classic example of a test of criminal responsibility and stating that a defense based on a plea of insanity must prove that, at the time of the act, the accused individual was mentally ill, and was not aware of the nature and quality of the act, or, if aware, did not know the act was wrong.

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M'Naghten rule [mik-naw´ton]

a definition of criminal responsibility formulated in 1843 by English judges questioned by the House of Lords as a result of the acquittal of Daniel M' Naghten on grounds of insanity. It holds that “to establish a defense on the ground of insanity, it must be clearly proved that, at the time of committing the act, the party accused was laboring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing, or, if he did know it, he did not know he was doing what was wrong” and further that a defendant who “labors under partial delusions only and is not in other respects insane… must be considered in the same situation as to responsibility as if the facts with respect to which the delusion exists were real.” These rules are still used in many American jurisdictions.