This is not a science fiction question. Embryo selection using polygenic scoring is commercially available now. Heritable gene editing has been done — once, recklessly, in 2018. The line between preventing disease and designing people is not bright, it is not fixed, and it is moving toward us faster than the ethical conversation can keep up.
Almost everyone agrees that preventing a child from inheriting a devastating genetic disease — Tay-Sachs, Huntington's, cystic fibrosis — is a good thing. Preimplantation genetic testing during IVF has been doing this for years, and the ethical consensus around it is relatively strong.
The difficulty begins when the same technology is used for traits that are not diseases. Companies now offer polygenic risk scores for embryos — statistical estimates of the likelihood of complex traits like height, intelligence, and depression risk, based on combinations of hundreds or thousands of genetic variants. These scores are probabilistic, not deterministic. They do not guarantee outcomes. But they shift the odds, and parents are willing to pay for that.
The slope is real but not necessarily slippery. Each step — from screening for lethal diseases to screening for serious chronic conditions to screening for statistical predispositions to selecting for preferred traits — involves a different ethical calculus. The problem is that the technology does not enforce these distinctions. It provides information. What parents do with that information is a social and regulatory question.
Heritable gene editing — actually modifying the DNA of embryos in ways that are passed to future generations — raises the stakes further. He Jiankui's 2018 experiment was condemned as premature and reckless, but it demonstrated that the capability exists. If the safety concerns are eventually addressed, the ethical questions remain: who decides what modifications are acceptable? And on what basis?
The book's Could We? Should We? framework is at its most powerful here. The capability exists. The demand exists. The market exists. The question of whether it should proceed — and under what constraints — is being answered de facto by individual parents, fertility clinics, and startup companies rather than by any kind of collective deliberation.
The Informed Consent problem is uniquely acute. The person most affected by these decisions — the child who will be born — cannot consent. This is not an abstract philosophical point. It is the defining ethical feature of heritable genetic intervention: the consequences are borne by someone who had no voice in the decision and no ability to reverse it.
The book's treatment of Human Dignity through Never Let Me Go asks what happens when human beings are treated as things to be optimized — created to serve purposes determined by others. The parallel to genetic selection is not exact (selected children are not clones grown for organ harvesting), but the underlying question rhymes: at what point does optimization become objectification?