There’s no shortage of true crime, and there hasn’t been since Cain murdered Abel. Fast forward and, turning from fratricide to parricide, we have the murders of Rob and Michelle Reiner, allegedly at the hands of their son. Nor is there any shortfall of state violence. The protests in response to an ICE agent’s killing 37-year-old Renee Good will no doubt continue.

Given the persistent and pervasive character of violent crime, we can expect that the debate about the legitimacy of capital punishment will continue. We can also expect more executions; this past year, there were 44 — the highest in more than a decade. Many Catholics, moreover, support capital punishment. A recent EWTN survey of 1,000 Catholic voters found that 55% of them support the death penalty “for a person convicted of murder.”

Edward Feser and Joseph Bessette, in their By Man Shall His Blood Be Shed (Ignatius, 2017), present the strongest case I’ve seen for capital punishment. Nonetheless, it fails. In this post, I’ll consider only a single reason why. Their argument depends on the principle of proportionality. It is a common-sense principle and, not surprisingly, one that Thomas Aquinas affirms. It does not, however, apply itself; nor is it independent of the imperative to love one another as God loves us.

Gilbert and Sullivan give us a “pop” version of the principle. The Mikado himself repeatedly urges us to “let the punishment fit the crime.” But the question that remains is just how to secure the fit. More than a century earlier, Samuel Johnson had noted the problem. In an essay for The Rambler (1751), he observes that

A slight perusal of the laws by which the measures of vindictive and coercive justice are established, will discover so many disproportions between crimes and punishments, such capricious distinctions of guilt, and such confusion of remissness and severity, as can scarcely be believed to have been produced by publick wisdom, sincerely and calmly studious of publick happiness.

And his reflection came well before today’s heavy reliance on plea-bargaining!

But let’s turn to St. Thomas. In support of capital punishment, his Summa Contra Gentiles teaches that “punishment should proportionally correspond to the fault.” He appeals to the principle of proportionately as follows:

Since divine justice requires, for the preservation of equality in things, that punishments be assigned for faults and rewards for good acts, then, if there are degrees in virtuous acts and in sins…there must also be degrees among rewards and punishments. Otherwise, equality would not be preserved (SCG III, 142).

Note that for Thomas the principle in question serves to preserve equality. It’s clear enough how it does so, to use his language, “in things.” But how are we to preserve equality when we turn from things to the basic goods of the human person?

Each person is created in the image and likeness of God. As such, each person has a core dignity. Indeed, every human life is an incommensurable and irreplaceable good. Yes, Cain kills Abel and does so with great malice. But killing Cain does not restore Abel; whatever arithmetical function it serves, executing Cain does not restore an equality of persons. Each person is, so to speak, beyond price. Let us banish Cain, and every modern murderer, from our midst. Beyond that expulsion, it suffices that we repel murderers, when necessary, with acts of self-defense that prove lethal.

The right use of the principle of proportionality requires that we understand the human person in proportion to a Revelation that gives us a stunning new insight into love: we are to love even our enemies as God loves us. The secular public square does not give this Revelation a serious hearing. That forum is keyed to a curious utilitarianism of the passions. Upon inspection, it everywhere admits to a reliance, however disguised, on torture as the proper punishment. I’ve only too often heard an otherwise (mostly) sober citizen opine that “hanging is too good for him.” And whole empires have relied on crucifixion — even of thieves. Yet the Lord of Life, on the way to the cross, prayed “Father, forgive them, for they know not what they do” (Luke 23:34).