The M’Naghten Rule 1843 – Criminal Law
Daniel M’Naghten (1813–1865), Edward Drummond (1792–1843), Nicholas Conyngham Tindal (1776–1846), Queen Victoria (1819–1901)
A test used to assess whether a person accused of committing a crime was sane at the time of the crime and hence criminally accountable.
The M’Naghten rule is used to determine if someone is insane enough to commit a crime. A criminal defendant is not guilty by reason of insanity under the M’Naghten rule if, at the time of the alleged criminal act, she was so deranged that she did not know the nature or quality of her actions, or if she did know the nature and quality of her actions, she was so deranged that she did not know what she was doing was wrong.
Daniel M’Naghten, who attempted to assassinate England’s prime minister Sir Robert Peel in 1843, is the inspiration for the M’Naghten rule on criminal insanity. M’Naghten mistook Peel for a murderer and attempted to shoot him, but instead murdered Peel’s secretary, Edward Drummond. M’Naghten was declared not guilty by reason of insanity after medical experts testified that he was crazy.
The House of Lords in Parliament instructed the Lords of Justice of the Queen’s Bench to draft a stringent definition of criminal insanity in response to popular outrage. The Lords of Justice agreed, declaring that insanity was a defense to criminal charges only if, at the time of the act, the party accused was suffering from such a defect of reason, resulting from a mental disease, that he did not know the nature and quality of the act he was performing; or, if he did know it, he did not know he was doing something wrong. (Queen v. M’Naghten, 8 Eng. Rep. 718 ; Queen v. M’Naghten, 8 Eng. Rep. 718 ; Queen v. M’Naghten,
The M’Naghten rule was designed to keep the INSANITY DEFENSE limited to cognitive insanity, or the inability to tell right from wrong. Since M’Naghten, various tests devised by legislators and courts have complemented the M’Naghten rule with another type of insanity known as volitional insanity. Mentally healthy people who, despite knowing what they are doing is unlawful, are so mentally unstable at the moment of the illegal act that they are unable to conform their acts to the law are said to be suffering from volitional insanity.
Daniel M’Naghten attempted to assassinate England’s prime minister, Sir Robert Peel, in 1843. M’Naghten was declared not guilty by reason of insanity during his trial.
Most jurisdictions in the United States accepted the M’Naghten rule, although legislators and courts eventually amended and broadened the concept. The concept of criminal insanity presently varies by jurisdiction, although the M’Naghten rule has affected the majority of them.
Many jurisdictions reject volitional insanity but keep the M’Naghten concept of cognitive insanity with minimal changes. A person was legally insane under the M’Naghten rule if she was so disordered that she had no idea what she was doing. A person is criminally insane under several contemporary legislation if she is so disordered that she lacks considerable capacity to recognize the illegality of her actions.
The distinction between the two definitions is mostly a matter of semantics. In principle, the latter definition is more forgiving because it simply needs a person to be incapable of appreciating her own actions.
The Law Book: From Hammurabi to the International Criminal Court, 250 Milestones in the History of Law (Sterling Milestones) Hardcover – Illustrated, 22 Oct. 2015, English edition by Michael H. Roffer (Autor)