On June 20, 2002, the United States Supreme Court decreed, in the case of Atkins v. Virginia, that the mildly mentally retarded were categorically exempt from capital punishment, reasoning that fully functional adults of diminished mental capacity were as a matter of law not as culpable for their acts. Writing eloquently in dissent, Justice Scalia drew a sharp distinction between the severely mentally retarded (who are truly not responsible for their actions), and the merely stupid (the category into which Mr. Atkins undoubtedly fell). Scalia argued forcefully that, with respect to the merely stupid, at least sometimes they deserve to...