M'Naughten Rule Definition and Legal Meaning

On this page, you'll find the legal definition and meaning of M'Naughten Rule, written in plain English, along with examples of how it is used.

What is M'Naughten Rule?

(n) M’Naughten Rule provides the test of legal sanity of the person involved in a wrongful activity to find whether he can distinguish between the right or wrong and to judge whether he has done any crime or not

History and Meaning of M'Naughten Rule

M'Naughten Rule is a legal test used to determine whether a defendant is legally sane or insane at the time of a crime. It originated in England in 1843 after Daniel M'Naughten attempted to assassinate the British Prime Minister but was acquitted on the grounds of insanity. The rule was subsequently adopted in the U.S. and other countries as a standard for determining legal insanity. According to the M'Naughten Rule, a person is not responsible for a criminal act if, at the time of the act, he or she was suffering from a mental disorder that caused a defect of reason, precluding the ability to comprehend the nature and quality of the act or to distinguish right from wrong.

Examples of M'Naughten Rule

  1. John is on trial for murder, but his defense argues that he was suffering from schizophrenia at the time and was unable to understand the consequences of his actions according to the M'Naughten Rule.

  2. Mary is accused of stealing a car but claims that at the time of the theft, she believed the car was hers due to a mental disorder. Her lawyer invokes the M'Naughten Rule to argue that she is not responsible for the theft.

  3. A defendant in a robbery case claims that he thought he was in a movie and not committing a real crime due to a mental disorder. The M'Naughten Rule is used to determine whether he was legally sane at the time.

Legal Terms Similar to M'Naughten Rule

  1. Durham Rule - Another legal test used to determine legal insanity in which a person is not responsible for a criminal act if it was the product of a mental illness or defect.

  2. Insanity Defense - A legal defense in which a defendant claims to have been insane at the time of a crime, making them not responsible for their actions.

  3. Competency to Stand Trial - A legal term used to determine whether a defendant is mentally capable of participating in a criminal trial and assisting in their own defense.