Whether "incapable of distinguishing right from wrong" in Colorado's insanity statute refers to legal wrong or moral wrong.
Holding
It refers to a cognitive inability, caused by mental disease or defect, to distinguish right from wrong under existing societal standards of morality, not merely to know whether conduct is illegal.
Reasoning
Colorado's statute adopted the right-wrong branch of the M'Naghten rule. Reading M'Naghten as a whole, the Court concluded that its focus was not simply on a defendant's technical awareness of the positive law, but on whether the defendant knew the charged act was one he ought not do. The term "wrong" therefore carries its ordinary moral meaning rather than meaning only "illegal."
A strictly legal test would disregard the psychological foundation of the insanity defense. A person in an extreme psychotic state may know that an act is prohibited by law while being unable, because of the psychosis, to comprehend that the act is morally wrongful. Conversely, a mentally ill person who knows an act is morally wrong remains accountable even if the illness leaves that person unaware that the act is formally illegal.
The statute's warning not to confuse insanity with "moral obliquity" supports this reading. That language separates a mentally ill person who cannot distinguish right from wrong from a person who understands prevailing moral standards but perversely chooses to reject them. It does not redefine wrong as legal wrong.
The relevant moral standard is societal, not personal. Moral understanding is shaped by the community's shared ethical norms, and a purely subjective test would permit acquittal whenever a defendant personally believed an act was right—even if the act was prohibited by law and condemned by society. Such a personal disagreement with society's morality is not legal insanity.