The four occasions when the overlapping and confusion occur are the inquiries regarding a person's triability, (competency to stand trial), the inquiries regarding the person's responsibility for the crime, discussions of the issue of punishability, and decisions regarding the appropriate treatment of mentally ill criminals. These are all separate questions, and the Nation's two distinct powers should be used separately to deal with them. An ambivalent attitude toward the mentally ill criminal has produced the difficulties with the principle of total separation of these two powers. Using the principle of separation, no special plea of incompetency to stand trial should exist. Similarly, there should be no special defense of insanity to a criminal charge. In addition, mental abnormality should remain relevant to the sentencing of convicted criminals. Moreover, special institutions for the criminally insane should not exist, since they are doubly stigmatizing institutions that seem to combine the worst features of prisons and mental health institutions.