Peter Singer Criticizes Pope Leo’s Encyclical for Embracing Human Exceptionalism

The utilitarian bioethicist Peter Singer opposes human exceptionalism. Indeed, he contends that being human is irrelevant to determining moral value. What counts are capacities and the ability to suffer.

Singer advocates using the term “person” to identify individuals with the highest moral value. Since he believes that personhood is based on capacities, some humans are not persons — the unborn, infants, the profoundly cognitively disabled — while some animals are. This means that those animals matter more morally than the vulnerable humans he so casually depersonalizes.

It is thus unsurprising that Singer takes issue with Pope Leo’s encyclical on AI because of the document’s stalwart defense of universal human rights and its intense focus on the impact AI will have on humanity. From Magnifica Humanitas of His Holiness Pope Leo XIV on Safeguarding the Human Person in the Time of Artificial Intelligence (citations omitted; my emphases):

55. Human rights are inviolable, since they are “inherent in the human person and in human dignity.” Consequently, they are universal and inalienable. Precisely because they are grounded in the common dignity of every man and woman, they have practical consequences and legal effects, for “it would be vain to proclaim human rights if, at the same time, everything were not done to ensure the duty of respecting them, respect by all, in all places and for all.” Among these rights, the first is the right to life, from conception to its natural end, without which it is impossible to exercise any other right. When this fundamental right is denied — as in the cases of induced abortion, killing of the innocent and euthanasia — we are faced with choices that the Church considers gravely wrong.

56. Looking at our own time, we cannot ignore the fact that the protection of human rights has been exposed to two particularly serious dangers. The first is that these rights are declared in a purely formal sense, while technological progress continues alongside covert or overt violations of human dignity. The second, which is in fact the root of the first, is the inability to recognize the foundation of their universality, since we have abandoned “the search for the solid foundations sustaining our decisions and our laws.” Pope Francis urged us not to underestimate this last issue. He pointed out that when reason seriously examines human nature, it is capable of discovering values that apply to everyone, since they derive from human nature. If this task of inquiry were abandoned, it is conceivable that rights considered untouchable today might, in the future, end up being questioned or denied by those in power, perhaps after having obtained only an apparent consensus from populations that are frightened or manipulated.

Absolutely. This text goes far beyond the parameters of Catholic dogma to focus on the weight-bearing foundations of our liberty based in universal human equality.

And that is precisely the philosophy that Singer criticizes. Sure, he appreciates the pope’s warnings about AI and its potentially deleterious impact on human activities such as work. But Singer objects to the document’s “anthropocentric” focus.

In this regard, he makes two specific complaints. First, the pope discounts the potential personhood of AI, and second, the encyclical doesn’t bring animals equally into the focus of concern. From Singer’s “The Pope’s AI Vision and Its Limits:”

The encyclical’s framework rests on a conception of human dignity that reflects a specifically anthropocentric ethics. If AI systems do one day demonstrate consciousness, then an ethics built solely around human dignity will prove inadequate, in the same way that an ethics built solely around the interests of one nation, or one race, has always proved inadequate when extended moral consideration was required.

And as to animals:

The same anthropocentrism that limits the encyclical’s treatment of AI has a long history in Catholic moral thought. It led Thomas Aquinas, the most influential Catholic theologian of the past millennium, to deny that we have any duties to nonhuman animals. Although Pope Francis broke with that tradition, in the encyclical Laudato Si’, Leo appears to have reverted to it in Magnifica Humanitas. He calls for the vulnerable to be included, yet does not mention—not once, in 42,000 words—the billions of nonhuman animals whose lives and deaths are already being affected by the role AI is playing in the factory farms that inflict suffering on a barely comprehensible scale.

The same technocratic paradigm that treats workers as resources to be optimized also treats sentient animals as mere units of production. If the encyclical’s moral framework cannot accommodate that reality, it is not because the problem is small, but because the framework is too narrow.

This is what Singer and his ilk do frequently — conflate the treatment of nonhuman entities as somehow wrong because it would be so to treat humans in an equivalent manner.

But this is illogical. Discriminating against humans is immoral because doing so is to treat equals as if they are unequal. Treating humans differently than AI or animals is not wrong because that properly treats unequals for what they are: unequal.

As to AI, how can something that is inanimate be granted any intrinsic moral worth? It is true that AI systems will have almost infinite monetary value. They are going to be worth trillions. But do we owe machines anything at all? Not any more than we do a hammer.

Consider: AI systems will never be alive. They can’t “feel” anything, since feeling requires a body. Amazing computational abilities are not synonymous with consciousness. Neither are unprecedented capacities for problem-solving or mimicking human responses. AIs are mere tools — extremely sophisticated to be sure, perhaps too complex for our own good — but as mere machines, they possess no greater intrinsic moral importance than a toaster.

I don’t know Aquinas’s view on animals, but if Singer accurately describes them in the quote above, he was wrong. So was Descartes’ view toward animals. But the Catholic Church does not hold to those views. Nor should we who are not Catholic.

Capacities do matter when distinguishing between us and animals. Animals are not machines. They can feel pain, have emotions, and are alive. Consequently, as the only known true moral agents in the physical universe, we have duties toward animals — for example, the duty of humane care. That is an essential part of human exceptionalism.

But our higher obligations are to each other. So, Pope Leo was right to focus his thoughts and concerns on how AI will impact the human condition. That is both appropriate to his station and must be our most urgent concern as AI changes human society and impacts our future thriving.