When abolitionists attack the death penalty, they typically do so with a wide variety of arguments. Norms such as the value of human life and respect for human life often play a decisive role. For some abolitionists, the death penalty is wrong because it violates the offender's right to life. Others object on the ground that the state has no right to kill any of its prisoners. Some oppose the death penalty because they regard it as an affront to human dignity. Others argue that it is the unfair administration of the death penalty that warrants its abolition. Still others insist that the risk of executing the innocent outweighs whatever alleged benefits the death penalty provides; or that, all things considered, a policy of selective death sentences has less overall social utility--in particular because it squanders more scarce resources than a policy of no death sentencing. Still others (borrowing language from the United States Supreme Court) insist that "evolving standards of decency" condemn the death penalty today, even if they did not in previous centuries. Some oppose the death penalty not just because of what it does to the offender, but for what it reveals about us in tolerating, let alone advocating, such killings. All these moral concerns can be connected in various ways, but even without exploring such connections it is evident that there is much to think about from the moral point of view in evaluating and criticizing the death penalty. (1)
This is not the occasion to develop an adequate review and critique of the arguments that are implied by the aforementioned norms and relevant facts. I propose instead to present and discuss the one argument that I now think is the best argument against the death penalty. Its lineage can be traced back to the little book by Cesare Beccaria, An Essay on Crimes and Punishments, the tract usually credited with inspiring the abolition movement in Europe and beyond during the Enlightenment. (2) A version of this argument reappears in the concurring opinions of Justices Brennan and Marshall in Furman v. Georgia, (3) as well as in the recent papal encyclical, Evangelium Vitae. (4) The argument rests on a fundamental normative principle: given a compelling state interest as the goal or purpose, the government must use the least restrictive means sufficient to achieve that goal or purpose. More expansively, the principle (which is closely related to what students of American constitutional law recognize as a principle of "substantive due process") holds that if individual privacy, liberty, and autonomy (or other fundamental values) are to be invaded and violated, it must be because the end to be achieved is of undeniable importance to society and no lesser degree of interference will suffice. For convenience of reference, let us call this the Minimal Invasion Argument against the death penalty and the principle that generates it the Minimal Invasion Principle. To put it as bluntly as possible, the Minimum Invasion Argument amounts to declaring that the death penalty fails to satisfy a necessary condition of justified punishment.
Before proceeding further, I should note two things. First, in what follows I refer exclusively to evidence and data from the United States. Extending the argument to apply around the world, or even only to European nations, is feasible but beyond my present purpose. Second, the Minimal Invasion Argument can also be extended without much difficulty to other severe punishments, such as life imprisonment without the possibility of parole.
II The Minimal Invasion Principle
If an argument against the death penalty is to be constructed around this principle, at least three propositions must be accepted. First, punishment for crime must be in principle a legitimate practice in society under a liberal constitution. (The Minimal Invasion Argument is not designed for radical pacifists.) Second, the death penalty must be understood by its very nature to be more severe, invasive, and irremediable than the alternative which, for all practical purposes in contemporary society, is long-term imprisonment. …