To establish a defence on the ground of insanity, it must be clearly proved that, at the time of the committing of 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 he was doing what was wrong.
Authentication Score 1
Citation
Tindal, Nicholas Conyngham. Delivering an exposition of the rules. M'Naghten's Case. c. 1843, Palace of Westminster, London, England, UK.