Article adapted from episode content.
Few philosophers have shaped the field of bioethics as deeply as Peter Singer. His book Practical Ethics is among the most widely read texts on the subject anywhere in the world, a fixture in graduate schools across the globe. For pro-life advocates, that influence is precisely why Singer deserves a careful hearing. Ideas that take root at the highest academic levels rarely stay there; they trickle down into the culture, shaping how ordinary people think about who counts as one of us and who does not. To answer Singer well, we first have to understand him accurately—both what he gets wrong and, surprisingly, what he gets right.
What Singer Actually Believes
Singer’s view of the unborn, the newborn, and even the toddler rests on a single, radical claim: you are not the same being today that you were when you were an embryo, a fetus, or a newborn. He readily concedes the biological fact that your bodily existence began at conception. He states this often. But for Singer, biological continuity is not what matters. What matters is mental continuity—above all, a continuity of memory and self-awareness that links you to your earlier self.
This is a crucial and often misunderstood point. Singer is not merely arguing that the embryo or newborn is a human being who happens to lack rights. He is arguing that there was no you present at all in those early stages. Until an organism can value its own existence and possesses a continuity of memory, there is, on his account, no person there—no subject of rights, no enduring self.
This is what philosophers call the mental continuity view of personal identity, and it stands in direct opposition to the substance view. On the substance view, living things maintain their identity through time and change. Any physical change to your body that does not kill you leaves you the same being, because you are far more than the sum of your physical parts. You have an underlying nature that grounds your identity even as your body develops, gains and loses capacities, and changes dramatically over the years. Singer rejects this entirely. For him, the entity that was once an embryo, fetus, and newborn has no enduring identity as a subject of rights until the relevant mental capacities appear.
Singer’s Definition of Personhood
Much of the heat generated around Singer focuses on his conclusions—that no newborn should be regarded as a person until well after birth, and that disabled infants might be killed if it suits the preferences of their parents. These conclusions are indeed disturbing. But the more important matter, the one critics too often skip past, is how Singer defines personhood in the first place, because everything else follows from that definition.
For Singer, a person is one who has an awareness of his or her existence over time, an awareness of existence in different places, and a capacity for wants and desires regarding the future. Notice immediately what this excludes. Some human beings—the embryo, the fetus, the newborn, those with significant cognitive disabilities, perhaps someone in the grip of advanced dementia—will not meet this standard. Are they therefore outside the category of persons? Singer bites the bullet and says yes. They are indisputably human, he grants, but they are not persons with a right to life. Strikingly, he is willing to extend personhood to certain animals—dogs, cats, dolphins—while withholding it from human fetuses and newborns.
What Is Right About Singer
It may seem that Singer offers nothing a pro-life advocate could welcome. In fact, there is one point on which he is admirably clear. Singer insists that birth is morally irrelevant to the status of the unborn. Differences in size, level of development, environment or location, and degree of dependency, he argues, carry no moral weight whatsoever.
A pro-life advocate should recognize the shape of that argument at once, because it is essentially the pro-life case that there is no morally significant difference between the unborn human and the newborn human. Singer agrees there is none. But where the pro-life advocate uses this insight to elevate the unborn to the status of the newborn, Singer moves in the opposite direction. He downgrades the newborn to the status of a non-person and concludes that you may kill both. The agreement about birth is real, but the destinations could not be further apart.
Why Singer Still Calls Infanticide Wrong
Given all this, readers are often surprised to learn that Singer maintains infanticide is wrong. He does say so. But his reasoning reveals the foundation of his ethic. Killing a newborn is wrong, he argues, not because the newborn possesses intrinsic worth, but because doing so would likely have a negative impact on other interested parties. The parents may want the child even though it is not, on his definition, a person. If the biological parents do not, there may be adoptive parents who would be deprived of the happiness of raising the child. Killing the newborn might therefore diminish the total amount of happiness in the world.
Two things stand out. First, Singer’s ethic is utilitarian through and through. Second, what makes infanticide wrong on his view is never the child himself, but the effect of the child’s death on others. He is not affirming the newborn’s value when he opposes infanticide; he is weighing the preferences of interested bystanders.
The Trouble with Utilitarianism
This brings us to the deeper problem. Utilitarianism reduces morality to securing the greatest good for the greatest number, and that principle runs into serious difficulty almost immediately. Consider: what, on strictly utilitarian grounds, would be wrong with framing an innocent man for a murder he did not commit, if doing so would prevent a city from rioting and spare hundreds of people from harm? If the only measure is aggregate welfare, it is hard to see why such an injustice would be forbidden.
A second problem is that utilitarianism cannot stand on its own. It must borrow from other moral systems to be complete, because it offers no way to define what “the good” actually is without appealing to some objective standard outside itself. Imagine a developer who wants to displace five hundred low-income families—families who own their modest homes—in order to build a stadium, restaurants, and an entertainment complex. He assures the city council that the community’s overall happiness will increase. But how does anyone measure whether this is good for those families? What if, five years later, none of them can afford another home because interest rates have climbed? The calculus that looks tidy in the aggregate dissolves the moment we ask what is genuinely good for particular human beings.
The Ambiguity of “Self-Awareness”
The decisive weakness in Singer’s position, however, lies in his concept of personhood itself, and specifically in what he means by self-awareness. The term is dangerously ambiguous, and each available reading creates problems.
Does Singer mean actual self-awareness? If so, then I am not a person while I am asleep, since I am not at that moment exercising any awareness of myself. Does he mean the immediately exercisable ability to be self-aware? That reading would protect me while sleeping, but not while I am under anesthesia during surgery, when no such ability is available to me. Or does he mean a natural capacity for self-awareness—a capacity rooted in the kind of being I am? Only this last reading protects the sleeping person and the patient under anesthesia. But if that is the standard, then the embryo qualifies as well, for the human embryo possesses a natural, intrinsic capacity for self-awareness and rationality. Unlike an amoeba, which will never be rational because of the kind of thing it is, the embryo lacks only time and development to express capacities already present in its nature.
Singer appeals to John Locke to argue that there is no right to life until one can recognize right and wrong and grasp one’s identity over time. But Locke, read carefully, was not addressing moral status; he was addressing moral responsibility. Locke’s point was that we cannot hold a being morally accountable until it can exercise such capacities—not that the being is a non-person without rights until then. Singer has confused accountability with worth.
Why These Traits Cannot Be What Give Us Value
We can press one further question: why are the particular traits Singer selects the ones that confer value? Why should existing over time, or in different places, matter so much?
The philosopher Chris Kaczor offers a memorable thought experiment. Imagine beings called “weather watchers”—highly intelligent creatures who do nothing but sit perfectly still on the coastline, observing weather patterns and calculating the speed and arrival of incoming storms with astonishing precision. They are unmistakably persons, yet they never change location. Would they be disqualified for failing to exist “in different places”? The criterion suddenly looks arbitrary. Consider desire as well. A slave can be conditioned not to desire his freedom; does that erase his right to it? A Buddhist or Stoic might cultivate a state of having no desires at all; may we therefore kill them?
Most telling is the case of harm. Suppose a woman lies in a coma and a criminal assaults her while she is wholly unaware. She has no experience of the act, no awareness of it across time or place. Was she nonetheless harmed? Surely yes. And we would not say merely that her body was harmed while she was not. We would say she was harmed. An attacker who assaults your body has assaulted you; we do not say he injured your arm but left you untouched. This exposes the body-self dualism running through Singer’s whole framework—the strange assumption that the real “you” floats free of the living body you are. It does not survive scrutiny.
Conclusion
Peter Singer is a careful and consistent thinker, and that is exactly why his argument is so instructive. His conclusions about newborns and the disabled follow logically from a definition of personhood built on mental continuity and a utilitarian ethic. But the definition is arbitrary at its root—he gives no compelling reason why his chosen traits are the ones that confer value—and the ethic beneath it cannot tell us why framing an innocent man would be wrong. When we recognize that human beings have value in virtue of the kind of beings they are, rather than the immediate exercise of a shifting list of capacities, Singer’s edifice gives way. The newborn is not a person on Singer’s terms. On any view that can actually account for the sleeping, the anesthetized, and the comatose among us, the newborn is a person after all.