The immorality of execution is based on a parallel between the first-degree murderer’s premeditated killing of his victim and the law’s subsequent premeditated killing of the murderer. In this view, we must “put behind us the notion that the second wrong makes a right. ...”289 The two events are certainly parallel as physical actions, but if that principle determines morality, it would be equally immoral to take back by force from a robber what he had taken by force in the first place. It would be equally immoral to imprison someone who had imprisoned someone else. It is another case of the physical fallacy — regarding things which are physically the same as being the same in value; in this case, moral value. By this standard a woman who uses force to resist rape would be as immoral as the would-be rapist. Insofar as he is successfully beaten off, all that has happened physically is that two people have been fighting each other. No one would regard the physical equivalence as moral equivalence. When the physical parallel involves human life, the stakes are higher, but the principle does not change. The morality of execution does not depend upon physical parallels.
Sometimes the claim of immorality is based on a supposedly inadvertent revelation of shame by the unwillingness of most people — even advocates of capital punishment — to witness an execution.290 But most people would not want to witness an abdominal operation, and yet no one regards that as evidence of immorality in such operations. Nor would a philanthropist who donated money to a hospital to advance such operations be considered a hypocrite if he declined an invitation to watch the surgery. Such arguments are even more difficult to take seriously, when the very same proponents claim that it was immoral for people to watch executions when they did,291 and that it is immoral for us not to watch them now.292
The argument that capital punishment does not deter glosses over some important distinctions. Any punishment may deter either by incapacitating the criminal (temporarily or permanently) from repeating his crime, or by using him as an example to deter others. Clearly capital punishment incapacitates as nothing else. The obviousness of this in no way reduces its importance. It is especially important because the attempt to incapacitate by so-called “life sentences” means nothing of the sort, and can mean that a first-degree murderer will be back on the street within five years legally, and of course sooner than that if he escapes. He can also kill in prison. Arguments about the supposedly low recidivism rates of murderers in general are beside the point. They would be relevant if the issue were whether all murderers must always be executed regardless of circumstances. But that is not the law at issue, nor have American judges and juries followed any practice approaching that. What is at issue is whether courts shall have that option to apply in those particular cases where that seems to be the only thing that makes sense.
The irrevocable error of executing the wrong person is a horror to anyone. The killing of innocent people by released or escaped murderers is no less a horror, and certainly no less common. The recidivism rate among murderers has never been zero, nor can the human error in capital cases ever be reduced to zero.