Law Dictionary

M'Naghten test

noun M'Naght·en test \mək-ˈnät-ən-\

Legal Definition of M'Naghten test

  1. :  a standard under which a criminal defendant is considered to have been insane at the time of an act (as a killing) if he or she did not know right from wrong or did not understand the moral nature of the act because of a mental disease or defect —called also M'Naghten rule — compare diminished capacity, durham rule, irresistible impulse test, substantial capacity test

Additional Notes on m'naghten test

Many jurisdictions have followed the Model Penal Code in basing criminal insanity on either of two factors: an inability to appreciate the wrongfulness of an act, which reflects the influence of the M'Naghten test, or an inability to conform one's behavior to the dictates of the law, which reflects the concept of the irresistible impulse. Both factors must be rooted in a mental disease or defect, which is also what the Durham rule requires of insanity.

Origin and Etymology of m'naghten test

after Daniel M'Naghten, defendant in 1843 murder case heard before the British House of Lords who was acquitted due to his insanity

Seen and Heard

What made you want to look up M'Naghten test? Please tell us where you read or heard it (including the quote, if possible).


to criticize severely

Get Word of the Day daily email!