Illustration of four figures sketching in a man

The Non-Identity Non-Problem

Around this time last year, I wrote a blog post for the Hastings Center, in which, in the context of responding to Professor Vardit Ravitsky’s report on reproductive autonomy and public health, I made the argument that when considering the ethics of selective abortions, we do not always confront a philosophical issue of non-identity because we can, in some cases, consider two genetically distinct embryos the same person.

Nobody buys my argument.

Some see it as indicative of the moral decline of Christendom. Derek Parfit, the progenitor of the non-identity problem, dismisses this notion without much analysis. My friends look at me like a crazy person every time I bring it up. Nevertheless, having now actually read Parfit’s analysis on this point, I still think I’m right. And I think I’m right in Parfit’s own terms.

It is worth reiterating that this argument is predicated on the controversial assumptions that an embryo is not itself a person. Many people think this assumption is false. They may be right. I certainly cannot prove that they are wrong. But that an embryo is not itself a person is the assumption of American law. And given that, it seems like a reasonable assumption to make, if for no other reason than to see where it leads us. My point, then, is that if you disagree with me because you believe that each distinct embryo a different person as a matter of definition, your objection was never so much to my argument as to its assumption.

Second, it is worth understanding the moral stakes of my argument. If I am right there is a straightforward moral duty to cure genetic diseases by selection where feasible. Most people would agree that if a child with cancer could be cured at relatively low cost to her parents, it would be immoral for the parents not to do so. Similarly, if embryo A and (currently hypothetical) embryo B are (or could be) the same person, and embryo A has a genetic disease that will give him childhood cancer, while embryo B is unlikely to, it would be immoral not to try to replace A with B. This logic is not, in itself, particularly controversial. Indeed, Parfit himself gets to this basic moral conclusion. But he does so through a convoluted argument that actions can be immoral even if they don’t harm anyone that is at least as implausible as mine.

Parfit accepts my premise. The assumption on which he builds the non-identity problem is not, in fact, that every successful act of copulation must produce a unique person. Rather, the claim is that “[i]f any particular person had not been conceived within a month of the time when he was in fact conceived, he would in fact never have existed.” (emphasis added). Why does Parfit include this apparently arbitrary temporal qualification? Because he sees the question of personal identity as a much closer case where the same egg is fertilized by a different sperm: “This child would have had some but not all of my genes. Would this child have been me? … There are cases in which our identity is indeterminate.” In other words, a child conceived instead of us that was the result of the fusion of the egg that made us and a different sperm, we may or may not have been the same person. Parfit admits he’s excluding these cases because he “want[s] [his]…Claim not to be controversial.

But we don’t only share “some but not all” of our genes with hypothetical alternative combinations of the same egg with different sperm. We share “some but not all” of our genes with any embryonic product of our parents’ copulation (these are usually called our siblings, but that is because we exist). Granted, we share more of our genes with Parfit’s hypothetical within-a-month alternative (roughly an average of 75 percent, versus an average of 50 percent with a child conceived at a different time). But it is hard to see what moral difference this 25 percent of genetic relatedness could make. It’s even harder when we realize that these percentages are only averages, and could we could be more or less related in particular cases.

The argument that a spectrum of genetic relatedness cannot make a moral difference parallels Parfit’s argument in the chapters preceding. There, he argues against a non-reductionist view of personhood by pointing out that such views require us to be able to say that there would be some point on the gradual spectrum of his psychological transformation from Derek Parfit to Napoleon Bonaparte at which he ceases to Derek Parfit and becomes definitively Napoleon Bonaparte. This point, he says, cannot be discovered. Therefore, the reductionist view of personhood is right, and in some cases personhood will be indeterminate.

This argument applies with the same force to the question of genetic relatedness to our alternatives. Parfit concedes that whether a 75 percent genetically related alternative is the same person may be indeterminate. He assumes this isn’t true with a 50 percent related alternative. He therefore must be able to defend a particular point on this spectrum at which the question goes form indeterminate to determinately different. This point, obviously, is impossible to discover. Therefore, the question of whether a genetically related alternative to us is us is indeterminate.

For Parfit, if the answer to a question about personhood is indeterminate, it is an empty question. That is, it has no answer. We can answer it however we want, but the answer doesn’t tell us anything more than the facts alone. My theory has no problem with that. We can call the new embryo the same person, or we can call it a different person. We won’t necessarily be right or wrong either way. Parfit, therefore, must be fine with my calling it the same person. And what we do know for sure are the facts: what we have in the world is a person that is better off than he or she would have been.


James Toomey is a 2018-2019 Petrie-Flom Center Student Fellow. 

James Toomey

James Toomey is an Assistant Professor of Law at the Elisabeth Haub School of Law at Pace University. Prior to joining the faculty at Pace, James was a Climenko Fellow & Lecturer on Law at Harvard Law School. His scholarly work has appeared in the Virginia Law Review, the North Carolina Law Review, the Harvard Journal on Legislation and more.

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