Should Moussaoui Die?

There is no question in my mind but that Zacarias Moussaoui is twisted and evil:

Moussaoui said he had "no regret, no remorse" about the 9/11 attacks. Asked by prosecutor Rob Spencer if he would like to see it happen again, Moussaoui responded: "Every day until we get you." (Link)

But should he put to death?

The best analysis of the morality of the death penalty I've ever read was Avery Cardinal Dulles' April 2001 First Things article Catholicism & Capital Punishment. His careful and nuanced analysis concludes by extracting 10 theses from the Magisterium:

1. The purpose of punishment in secular courts is fourfold: the rehabilitation of the criminal, the protection of society from the criminal, the deterrence of other potential criminals, and retributive justice.
2. Just retribution, which seeks to establish the right order of things, should not be confused with vindictiveness, which is reprehensible.
3. Punishment may and should be administered with respect and love for the person punished.
4. The person who does evil may deserve death. According to the biblical accounts, God sometimes administers the penalty himself and sometimes directs others to do so.
5. Individuals and private groups may not take it upon themselves to inflict death as a penalty.
6. The State has the right, in principle, to inflict capital punishment in cases where there is no doubt about the gravity of the offense and the guilt of the accused.
7. The death penalty should not be imposed if the purposes of punishment can be equally well or better achieved by bloodless means, such as imprisonment.
8. The sentence of death may be improper if it has serious negative effects on society, such as miscarriages of justice, the increase of vindictiveness, or disrespect for the value of innocent human life.
9. Persons who specially represent the Church, such as clergy and religious, in view of their specific vocation, should abstain from pronouncing or executing the sentence of death.
10. Catholics, in seeking to form their judgment as to whether the death penalty is to be supported as a general policy, or in a given situation, should be attentive to the guidance of the pope and the bishops. Current Catholic teaching should be understood, as I have sought to understand it, in continuity with Scripture and tradition.

As they say in the blogosphere, go read the whole thing.

I take it that, as applied to Moussaoui, the critical theses are #s 7 and 8. Can the legitimate goals of punishment be accomplished by imprisonment? Executing Moussaoui obviously precludes any chance that he can be rehabilitated and brought to remorse. Conversely, society can be protected from him by locking him up and throwing away the key. So the argument for death must be either that executing Moussaoui is necessary to deter others or to achieve retributive justice. As to the former, wouldn't the prospect of martyrdom encourage Islamic terrorists as opposed to deterring them? As for retribution, was Moussaoui sufficiently closely involved in the 9/11 attack to deserve death in response? I haven't followed the trial closely enough to know the answer to that question, but my impression is that only he knows for sure, and that he may well be deluding even himself.

As for #8, I think the key issues are whether (1) executing Moussaoui will make society more or less vulnerable to terrorism and (2) we are executing him not because of whatever he may have done but as a substitute for the actual 9/11 conspirators who are now beyond human justice.

I'd love to know what Cardinal Dulles thinks. Personally, I think the death penalty always raises tough moral issues and this case is no exception.