The Insanity Defense: A Legal Concept

Insanity is a legal term used in the context of the criminal justice system, not a medical term. It is not based on psychiatric or neurological diagnoses. The insanity defense is raised in cases where the defendant argues that their mental illness prevented them from understanding the nature and consequences of their actions, or from distinguishing right from wrong. The McNaughton rule, established in 1848, sets the standard for the insanity defense: the defendant must prove that they had a mental disease or defect at the time of the crime and were unable to understand the nature of their act or that it was morally wrong. The defense hinges on whether the accused person had a guilty mind or not.