When we say that something is beneath our dignity, what do we mean, exactly, and how do we know? How should we define or measure dignity?

The experimental psychologist Steven Pinker believes such questions are impossible to answer conclusively and are therefore mostly useless in discussions about the ethics of medical research and therapy. For Pinker, the only proper concerns of bioethics are the relief of suffering and the principle of informed consent; anything else, including concern for human dignity, is at best a waste of time. Writing in the May 28 issue of the New Republic, Pinker calls dignity “a squishy, subjective notion, hardly up to the heavyweight moral demands assigned to it” by members of the President’s Council on Bioethics. The occasion of Pinker’s criticism is the council’s publication of a report titled Human Dignity and Bioethics, which includes essays by twenty-four experts, most of them members of the council.

Pinker’s first complaint is that the council and its report are dominated by Catholics and other religious zealots who wish to foist their sectarian agenda on the country by means of highly fanciful, nonscientific arguments. He is particularly unhappy that many of the essays in the collection refer to passages in the Bible and to works of imaginative literature such as Aldous Huxley’s Brave New World. The fact that many of the contributors work for Christian institutions (for example, Georgetown and Notre Dame) is treated by Pinker as evidence of a compromising religious “entanglement.” It would be a mistake to focus only on Pinker’s antireligious rhetoric about the “pervasive Catholic flavoring of the council,” especially since Pinker himself concedes in passing (and after some sneering) that the “validity of an argument cannot be judged from the motives or affiliations of its champions.” Still, the fact that Pinker has counted the number of times the word “dignity” appears in the Catechism of the Catholic Church (“more than a hundred”) and presents this as evidence of the term’s unsavory pedigree does say something about the nature of his indignation.

Pinker claims that the word “dignity” is too ambiguous to serve as an ethical criterion for science and medicine. The concept of dignity, he argues, is relative, fungible, and sometimes even harmful. That is, we disagree with our ancestors, and among ourselves, about what counts as undignified; we are all willing to give up a little of our own dignity for life, health, and safety; and we have all seen political and religious repression justified as a defense of someone’s dignity. Surely no one would dispute any of this. But when Pinker offers examples of the dignity we sacrifice in order to secure other goods, it becomes clear that he is building his argument on an equivocation. “Getting out of a small car is undignified,” he writes. “Having sex is undignified. Doffing your belt and spread-eagling to allow a security guard to slide a wand up your crotch is undignified.” Agreed. But when people speak of “human dignity” they are usually talking not about decorum or honor or the avoidance of embarrassment, but about a property that is supposed to belong to all people, in every condition, just by virtue of their humanity.

Pinker claims that dignity adds nothing that the concepts of autonomy and respect for persons don’t already give us. In fact, these concepts are no less ambiguous than dignity. Suicide and drug abuse can both be understood as an exercise of personal autonomy. Does that mean we must not try to prevent them? The principle of autonomy, like that of dignity, is not as simple as it sounds, and it does not always lead to less suffering. It, too, requires hard questions that Pinker does not answer or even ask in his essay. To begin with: Whose autonomy counts, and what counts as autonomy? “Respect for persons” also sounds like an uncontroversial rule, and yet it has failed to deliver a consensus on the kinds of issues the bioethics council was designed to address. Those who think abortion should be legal claim that their position is a matter of respect for persons, but so do those who think that abortion is a form of homicide.

Important as they are, the principles of autonomy and respect cannot interpret themselves, and they don’t promise the kind of perfect analytic precision that Pinker seems to demand of ethical concepts. That does not make these principles useless, of course, but it does mean that those who reject human dignity as the basis for our respect for persons and their freedom must offer a better alternative. Where there is no consensus about a matter of fundamental importance, it is not enough to appeal to common sense, or to delirious fears of theocracy.