Benjamin Gregg takes on important and timely issues in Creating Human Nature: The Political Challenges of Genetic Engineering. The rapidly developing biotechnologies of gene editing, embryo selection, and the like raise challenging ethical predicaments and regulatory challenges for democratic societies to navigate. Gregg’s contribution to these debates is a welcome one that helps fill what is something of a lacuna in normative political theory: theorizing about the significance and challenges of scientific innovation and the regulation of new biotechnologies. Gregg tackles these issues with both ambition and careful attention to the science.

Creating Human Nature concerns itself with the question, “What kind of human nature should humans want to create for themselves?” Advances in human genetics, like the sequencing of the human genome, the rapid expansion of genetic tests and clinical trials for gene therapy, and genome editing, have ushered in a new era of medicine where the prospects of personalized medicine and genetic engineering have shifted from the realm of science fiction to reality. Genetic engineering “refers to the genetic editing of living things—to the specific addition, removal, or modification of DNA sequences, for example, to correct a particular gene’s defective functioning in a specific biological context” (p. 42). Many scholars in the humanities and social sciences may shy away from these issues, at least in part, because of the troubling history of eugenics. The suggestion that science should be harnessed to directly manipulate our biology raises the worry that we may repeat the injustices of the eugenics movement that started in the 1880s and lasted into the mid-twentieth century. These injustices included racism, the exclusion of those already marginalized in society, and violations of reproductive liberty and other human rights.

Gregg begins Creating Human Nature by noting the prevalence of racism in the political writings of Western Enlightenment philosophers, ranging from Kant and Diderot to Rousseau and Voltaire. He contends that today the Enlightenment inspires a Janus-faced response to the prospect of human genetic engineering: “One face regards nature as yielding to culture: culture as human will and imagination in its limitless plasticity, as the capacity to shape and endlessly reshape ideas, artifacts, and institutions. The opposite face regards nature as a limit to human belief and behaviour: the ‘natural’ as a standard by which to reject the ‘unnatural’” (p. 3).

These two dimensions of Enlightenment thinking, contends Gregg, raise different concerns for the prospects of genetic engineering. The skeptical side will raise concerns about respect for individual autonomy and our identity as members of the species homo sapiens. By contrast, the optimistic side sees the potential that genetic manipulation offers to promote freedom by helping humanity more effectively abate disease and disability. The goal of Gregg’s book is to navigate a path between the skeptical and optimist faces of European Enlightenment. He believes this can be done by highlighting the political dimensions of human genetic engineering.

Perhaps one way to frame Gregg’s point more effectively would have been to devote a least one full chapter of the book to the details of past eugenic aspirations and policies and explore the lessons that could be learned from diagnosing their injustices. For example, this could have been done by explicitly highlighting their impoverished scientific understanding of human biology, as well as the racism and the other faulty moral premises of policies like the sterilization of “the unfit” and “positive eugenics” (e.g., encouraging those perceived to have desirable traits to breed). By doing so, Gregg’s aspiration to steer a judicious middle ground between skepticism and optimism about genetic engineering would have been more feasible than an abstract, ahistorical normative analysis. Instead, Gregg believes these problems can be abated by addressing the issue of genetic engineering from the methodology of “political bioethics.”

Greg’s account of political bioethics is the central focus of part 1. He develops this methodology along four dimensions (p. 13): method (proceduralism), standards of evidence (more than local, less than universal), a notion of human nature (socially constructed), and a conception of human dignity (autonomy). The proceduralism that Gregg champions combines expert committees with deliberative democracy. This part of the book will be of particular interest to political theorists because it engages with core normative concerns of the discipline concerning deliberation and democratic legitimacy. Political bioethics, Gregg contends, is “less plausible the more it presupposes shared common values or insists on creating them as the only acceptable grounds for regulation and public policy” (p. 38). The plausibility of political bioethics thus requires that regulatory decisions about genetic engineering be acceptable to both participants and affected persons. The legitimacy of just decisions arises from their basis in procedural legitimacy.

Despite the somewhat agnostic stance about the ethics and policy regulation of genetic engineering that a commitment to proceduralism would seem to entail, Gregg advances specific normative arguments and prescriptive conclusions that seem to be at least in tension with, if not contradictory to, the commitment to proceduralism and political bioethics. For example, Gregg rejects human nature-essentialism—the position that human traits are innate, invariant, universal, and unique (p. 65)—and appeals instead to a consequentialist notion of human dignity that regards all norms, including moral status, as social constructs. This consequentialist conception of human dignity places the primary moral concern on the future person’s “decisional autonomy” (p. 99). But at these points in Gregg’s argumentation I could not help but think back to his earlier claim that political ethics “is less plausible, the more it presupposes shared common values or insists on creating them as the only acceptable ground for regulation and public policy” (p. 38).

The potential tension between the commitment to majoritarian proceduralism and more substantive moral commitments is amplified in part 2; there, Gregg invokes the social good of democratic political participation to contend that the genetic engineering of embryos to overcome severe congenital cognitive disability may be justified. Invoking a specific account of political personhood to justify using genetic engineering of embryos to improve the likelihood that future persons will not fall below the threshold for participating in the processes of participatory politics raises a whole quandary of potential concerns that I think Gregg could have devoted more time to considering. For example, because Gregg’s analysis focuses only on the genetic engineering of embryos with a high risk of cognitive disability, there is some ambiguity about how far he believes society would be justified in aspiring to bring about this threshold for cognitive functioning.

The claim that there is “a human right to parental choice in genetic selection of embryos” (p. 176) presumes that prospective parents, or at least that small percentage undergoing IVF, will want to use genetic engineering to modify their embryos in the hopes that doing so would reduce the probability of their potential offspring having severe cognitive impairment. But what if the prospective parents do not want their embryos to be genetically modified? Are there limits on how far majoritarian proceduralism can go in promoting the social good of democratic political participation? What about mandating genetic testing for all prospective parents to discourage (at least) natural reproduction among carriers of conditions like Fragile X syndrome? Or encouraging large families among those deemed to have the best “genetic constitutions” for the realization of the intellectual virtues of democratic political participation? In other words, what constitutes a reasonable balance between respect for reproductive freedom and the aspiration to improve the deliberative and participatory aspects of the political community? Greater attention to such concerns would have strengthened Gregg’s analyses and demonstrated the importance of not repeating the mistakes of past eugenic policies.

There are also some surprising omissions from the book. Gregg’s focus on topics like intelligence, epigenetics, and the Anthropocene—a period in which the planet bears “a tectonic human impact on its ecosystems and geology” (p. 202)—provides valuable and distinctive contributions to these debates. But the book pays surprisingly little attention to the impact that genetic engineering could have on human health, especially across the complete lifespan. Aging populations are vulnerable to multimorbidity in late life, including diseases of the brain that undermine the social good of democratic political participation about which Gregg is concerned. But his narrow focus on the engineering of embryos means these other concerns and types of genetic intervention are not addressed.

The kind of project explored in Creating Human Nature requires a scholar to have the courage to take the intellectual risks inherent in developing an interdisciplinary normative analysis that yields some practical prescriptions for an area of scientific research where there still remains much uncertainty. And yet, at the same time, such an intellectual undertaking also requires a scholar to possess the requisite amount of intellectual humility to see the limits of what normative political theory can contribute to these complex issues. Gregg should be commended for his innovative efforts; his book will, I hope, inspire others in the field of political theory to devote more attention to these pressing issues.