The legal concept addresses situations where an individual, due to a mental disorder, lacks the necessary mental capacity to understand the nature and quality of their actions, or to appreciate that their actions were wrong at the time of an alleged offense. For example, a person experiencing a psychotic episode, genuinely believing they are acting in self-defense against a perceived imminent threat not based in reality, may be found to lack criminal culpability.
This determination acknowledges that holding such individuals accountable in the same manner as those with full mental capacity would be unjust. It stems from a legal tradition recognizing that blameworthiness requires both a wrongful act (actus reus) and a guilty mind (mens rea). Historical precedents can be traced back to early legal codes that distinguished between intentional wrongdoing and acts committed under conditions of insanity or diminished capacity. This finding does not equate to innocence; rather, it shifts the focus from punishment to treatment and public safety.
