What is the term for a defense when the actor, due to severe mental disease or defect, did not know their conduct was wrong?

The term that describes a defense wherein an individual, due to a severe mental disease or defect, does not understand that their conduct is wrong is referred to as insanity. This legal concept acknowledges that a person may lack the capacity to form the necessary intent for a crime because of a significant mental impairment. When successfully employed, the insanity defense can absolve the individual from criminal liability, as their mental state prevents them from comprehending the nature or wrongfulness of their actions at the time they were committed.

The insanity defense is critical in criminal law, as it reflects a fundamental principle that punishment should be based on an individual's ability to make reasoned choices. It emphasizes the importance of mental health considerations in the legal process. In contrast, intoxication pertains to impairment due to substances but does not encompass a permanent mental condition, while duress involves coercion that compels an individual to act against their will. Compulsion, while similar, generally refers to a situation where a person is forced to behave in a certain way but does not necessarily relate to the understanding or awareness of the wrongfulness of that conduct. Understanding these distinctions is key to applying the concepts correctly within legal contexts.