I am not asking them whether chattel slavery is morally wrong. We already agree on that point. I am asking what it is about chattel slavery that justifies our judgment that it is morally wrong.  It is like the difference between asking, “Is Michelangelo’s Pietà beautiful?” and “Why is Michelangelo’s Pietà beautiful?” The latter question presupposes that the answer to the first question is “yes,” which means that the second question is asking why the “yes” is justified.

“The slaves didn’t consent” is the answer I get from virtually all my students. But as they quickly learn, that answer is not capable of truly capturing their deeper intuitions about chattel slavery’s wrongness. After all, as I often respond, what if historians discovered a group of former American slaves a few years after the Civil War pining for their former life on the plantation? How we would react to such a revelation?

Would we say that this state of affairs could have developed into a case of morally permissible chattel slavery, if the former slaves had subsequently consented to return to their prior state, to become yet again under the law nothing more than another man’s property?

If you answer “yes,” then you believe chattel slavery is only conditionally wrong, that there is nothing intrinsically wrong with the practice. So, even though you may continue to condemn the institution, the grounds on which that condemnation rests – consent – implies that there is nothing essential about human beings that entails that we are not by nature property.

So, under this analysis, the wrong of chattel slavery depends not on who the victims are, but rather, on what the victims want. It suggests that the absence of volition, and not the presence of dignity, is doing the moral work in our condemnation of chattel slavery.

Yet many today are suggesting that when it comes to some of the great moral questions of our time, individual autonomy (or “consent”) is the only principle we need in order to secure all the goods for which more ancient understandings, such as human dignity, have been employed.

For example, the eminent Harvard psychologist, Steven Pinker, in a provocatively titled New Republic essay, “The Stupidity of Dignity, ” writes:

The problem is that “dignity” is a squishy, subjective notion, hardly up to the heavyweight moral demands assigned to it. . . .[Ruth Macklin has] argued that bioethics has done just fine with the principle of personal autonomy – the idea that, because all humans have the same minimum capacity to suffer, prosper, reason, and choose, no human has the right to impinge on the life, body, or freedom of another. This is why informed consent serves as the bedrock of ethical research and practice, and it clearly rules out the kinds of abuses that led to the birth of bioethics in the first place such as Mengele’s sadistic pseudo-experiments in Nazi Germany and the withholding of treatment to indigent black patients in the infamous Tuskegee syphilis study. Once you recognize the principle of autonomy, Macklin argued, “dignity” adds nothing.

 In Dr. Mengele’s case consent would not have made evil permissible

 Although much can be said in response to Pinker’s claim, as I point out in a 2010 article published in the journal Ethics & Medicine, it will suffice for our purposes here to draw on the sort of reasoning I employ with my students when I ask the question about chattel slavery.

What if, for example, we discovered the diaries of certain German citizens who volunteered to undergo the Nazi experiments in exchange for large sums of money that would be given to their survivors? Would the consent of these voluntary victims change Mengele’s pseudo-experiments from evil to good?

If not, it must be because these activities are intrinsically evil, and that agreeing to participate in them, whether as victim or assailant, cannot in principle change their nature. Thus, contra Pinker, dignity not only does not add nothing, mere consent subtracts everything.

I am, of course, not suggesting that consent does not matter for ethics. It is, for example, a necessary condition for the licitness of a marriage. There is, after all, such a thing as unjust coercion. Rather, what I am arguing is that the moral life cannot be reduced to mere consent, as many of our contemporaries, like Pinker, believe should be done.

For, as we have seen, when that reduction is applied to actual atrocities, our attention subtly shifts from what seems true at first sight – the intrinsic dignity of the human person – to  the deflated alternative which the modern mind thinks it can substitute without remainder: the conditional will of the individual chooser.

The implication of the latter is clear: there is no human good to which we are ordered and to which our wills should conform. Good is merely what we prefer, and to which we direct our wills. But in that case, we possess no intrinsic dignity, since such a property would be a good independent of what we will and under which our preferences should be ruled.

In effect, mere consent is the abolition of human dignity.