Review of Biotechnology, Human Nature, and Christian Ethics

Gerald McKenny, Biotechnology, Human Nature, and Christian Ethics. 
New Studies in Christian Ethics. 
Cambridge University Press, 2021. 
ISBN: 978-1-1084-3515-4 (paperback), 236 pages, $29.99.

For millennia, Christians have largely understood human nature to be something fixed and stable. And being made in the imago Dei, our human nature has traditionally carried with it a significant normative status. Now, fast forward to December 8th, 2023. On this date, the U.S. Food and Drug Administration (FDA) approved two treatments (Casgevy and Lyfgenia) representing the first cell-based gene treatments utilizing CRISPR/Cas9 technology for the treatment of sickle cell disease in patients 12 years and older. What might otherwise appear to be just another routine announcement from the FDA may, in time, pose a serious challenge to the long-held assumptions of our ancestors. After all, just consider what the widespread use of these biotechnologies implies: For the first time in human history, we now wield the technology to specially target and rewrite portions of our genome on a commercial scale in quite powerful ways—ways that could make changes not only to human nature but potentially of human nature as well. Will such technologies be able to seriously alter significant aspects of our human nature? Will we be able to become something other than human if we fiddle around with our genome too much? Will genomic changes threaten to undermine the imago Dei or our normative status?

These are the sorts of questions that motivated Gerald McKenny’s 2021 book Biotechnology, Human Nature, and Christian Ethics. Central to McKenny’s project is the conviction that the contemporary “implications of biotechnology for human nature”—like those mentioned above—“are not a matter of indifference for Christian ethicists because human nature is not a matter of indifference to Christian ethics” (3). Indeed, human nature is so important because, “for Christian ethics, normative status attaches to human biological nature, which is to say that human biological nature counts in the ethical evaluation of actions that implicate it” (5). So, on the one hand, Christians should care about how evolving biotechnologies implicate the biological aspects of our nature insofar as our normative significance “attaches to” our biological human nature in some way (though not exclusively or reductively). Yet, on the other hand, the claim that human nature should count in the evaluation of biotechnological interventions that implicate it is, as McKenny notes, “not necessarily to claim that it overrides all other relevant factors” either—but rather, just that “human nature should count in some fundamental and significant way in the ethical evaluation of biotechnologies that implicate human nature” (13–14).

The substance of McKenny’s book involves the examination of “four distinct versions of the claim that normative status attaches to human nature in the context of biotechnology” (8). The first chapter of the book is dedicated to introducing and motivating the project in addition to offering a brief overview of the four distinct versions of the view that normative status (NS) attaches to human nature. Hence, he labels these views NS1–NS4. The remaining chapters then focus on one particular view in order to describe it, address major criticisms, explain what is ultimately at stake for Christian ethics with respect to the view, and so on. His overarching goal is “to determine what the normative status of human nature is and how it counts in the evaluation of biotechnological interventions that implicate human nature”—which he hopes to accomplish by critically reconstructing and evaluating NS1–NS4 (13). And while McKenny concludes that “all four versions are indispensable to an adequate evaluation of biotechnological enhancement in Christian ethics” given that “each version preserves something that is essential to the theology and ethics of human nature,” he nevertheless disagrees that “all four versions are equally viable” (12). After a brief, summarizing conclusion at the end, McKenny then completes his book with a short appendix discussing the prospect of posthumanism.

Chapter 2 focuses on NS1—a view that McKenny labels Human Nature as Given. Proponents of this view contend that normative status attaches to human nature as “that which exists apart from intentional human action” (9). On what McKenny calls a broadly Augustinian view, the normative status of human nature is held intact when we merely heal or restore human nature to what it is (because creation is seen as a finished work) but violated when we alter human functions or traits beyond what they are. McKenny begins this chapter by clearing away four strawmen objections to NS1 and instead engages some of the best defenders of the view—e.g., C. S. Lewis, Oliver O’Donovan, Jürgen Habermas, and Michael Sandel. In the end, McKenny concludes that advocates of NS1 have failed to show “that biotechnological determination of human nature in principle involves illicit power over those whose nature is selected, altered, or controlled,” noting that such bioenhancements may actually “meet a genuine duty of parents to benefit their child and may thus be capable of being justified in principle” (68–69).

Chapter 3 pivots toward NS2—or Human Nature as Ground of Human Goods and Rights—which contends that normative status attaches to human nature as “the ground of human goods or rights” (9). On this broadly Aristotelian-Thomistic account, the worry is that the goods and rights grounded in human nature may eventually be imperiled if we alter the nature that grounds them. After all, these goods “fulfill human beings as the kind of being they are while human rights protect the pursuit of these goods” (11). The focus of this chapter is, then, to formalize and then respond to these and related challenges. McKenny concludes that imagining goods “that exceed the present capacity of our nature is not always a sinful refusal to be satisfied with what God offers us in our creaturely nature” (109). Indeed, he notes that such imaginings may, in a way, express “the insights that our nature in our fallen state does not reliably reflect the good for which we have been created and that the good for which we have been created is not fully intelligible in terms of our creaturely nature” (109). Thus, McKenny thinks that the biggest mistake of NS2 lies “in supposing that the normative significance of human nature is found in human nature, or more precisely, in a good that fulfills that nature as it is, rather than . . . its relation to something that transcends it (while also embracing it), grounding its meaning and worth from outside it” (109).

Chapter 4 then discusses NS3—or Human Nature as Susceptible to Intervention—which contends that normative status attaches to human nature “as indeterminate, open-ended, or malleable” (10). On what McKenny labels a broadly Irenaean view, we fulfill our “God-given vocation to bring human nature to its completion or perfection” insofar as creation is an unfinished work to be completed through a temporal process that may plausibly involve biotechnology (10–11). Chapter 4 begins by addressing two immediate objections to this view and ends with McKenny delivering significant blows to the account himself—contending that “neither the goodness of creation nor its status as a finished work is adequately defended by NS3” (143) and that “NS3 presumes that the eschatological perfection of creation is commensurable with what biotechnology can accomplish” (144). Indeed, McKenny thinks that such “Irenaean perfection . . . is indistinguishable from liberal eugenics,” arguing that “having been enticed at the prospect of participating in the divine task of perfecting creation,” this view will ultimately disappoint us when we discover that “perfection is found in the realization of certain commendable but ultimately banal values of late bourgeois society”—values that “do no more than suit people for the adaptability and productivity required by late modern economies” (136–37).

Finally, Chapter 5 discusses NS4—or Human Nature as Condition for Imaging God. In this view, normative status attaches to human nature as “that which suits or equips humans for a certain form of life with God and with other human beings” (10). On what McKenny calls a broadly Barthian view, human nature possesses particular God-given biological characteristics that suit us for “the form of life with God and with other humans for which God has created them” (10). The question posed to biotechnology, then, is whether its use instantiates or conflicts with the realization of our vocation to conform to Christ as the image of God. McKenny interacts primarily with the works of Kathyrn Tanner and Karl Barth throughout this chapter as apt defenders of versions of NS4. He concludes that neither version of NS4 “rules out the possibility that biotechnological alteration might contribute to life with God as Tanner and Barth understand it” because what remains pertinent to either account is whether “any such biotechnological alteration would instantiate the point of creaturely freedom (that is, its meaning or purpose as created by God)” (178–79).

With respect to what is good about this book, there is much to admire and commend. For example, the book is very readable at less than 200 pages, and it covers a wide range of key figures (e.g., Aristotle, Karl Barth, Martha Nussbaum, Leon Kass, Oliver O’Donovan, Michael Sandel, Francis Fukuyama, Kathryn Tanner, etc.) and their contributions to the discipline—even if their work only indirectly applies to biotechnology. Moreover, McKenny displays the virtues of modesty and charity insofar as he seems to hold back from drawing conclusions beyond what the arguments imply while also charitably applying criticisms to others as well. The book is also fairly comprehensive, as the ranges of views it discusses offer a broad overview of the live and competing positions. Finally, I appreciated the consistent retracing that was characteristic of this text as McKenny often restated and summarized his conclusions as well—which makes for a well-guided and guess-free reading experience. Given all this, I think graduate-level programs in bioethics and philosophy would do well to somehow include this book in their curricula.

With respect to criticisms and further questions, I will only mention a few. First, there was a lurking question about maintaining the comparative importance of each NS view when McKenny ultimately argued for “the superiority of NS2 and NS4 over NS1 and NS3 and then for NS4 over NS2” (12). In other words, it was not entirely clear how we could grant each view a legitimate place in the Christian evaluation of biotechnological enhancement while simultaneously endorsing the superiority of NS4—especially when these views are so drastically inconsistent with each other on key points. Second, there was a lurking question about the defeasibility of the normative status of human nature. While human biological nature might have some normative status that counts in the ethical evaluations of actions like bioenhancement that implicate it, exactly how helpful is it to say that this is a weighty yet defeasible consideration among other weighty, commensurable considerations? How do these normative considerations from human nature weigh against, e.g., bioethical principles of autonomy, nonmaleficence, justice, etc.? Is this a helpful action-guiding and decision-making framework when navigating the impending and complicated questions of bioenhancement?

Moreover, I would have liked to have seen further synthesis and explanation on some topics as well. For example, it seems like a larger project synthesizing the central claims of NS1 as the theologically preferable version to NS3 and NS4 as a theistically perfected version of NS2 would be welcomed and helpful. Second, a further explanation as to how bioenhancement could serve to glorify God would also be welcomed. Just consider, for example, that Barthian NS4 permits biotech enhancements that “contribute to the role of our nature in equipping us for life with God” (179). And biotech enhancements may, in principle, be permissible for NS1 proponents like O’Donovan so long as they do not violate the generic and teleologically created moral order. But these permissions seem fairly under-described, so further work on what a program of bioenhancement within their parameters might look like also seems welcomed. Finally, an expanded appendix would have been helpful as well, where further questions like “Is ‘posthumanism’ even possible if we’re just rational animals?” or “What is the relationship between posthumanism and Christology?” get addressed. Indeed, perhaps such comments have anticipated a future project either by McKenny or others.