The genetic engineering of human beings, for so long relegated to the realm of fiction, creeps ever closer to reality, and the closer it gets, the more pressing it becomes for Christian theology to address it. The term genetic engineering could refer to a wide variety of practices, but my comments in this essay will mainly address gene transfer, the direct alteration of an individual’s somatic or germ line cells. Somatic gene transfer changes the genes of an embryo, child, or adult but limits those changes to the individual, whereas germ line transfer affects the reproductive cells, which means that changes are passed on to that individual’s descendants. Depending on what genes are altered and for what reason, gene transfer is described as either genetic therapy or genetic enhancement:1 therapy seeks to cure or avoid a genetic disorder, like cystic fibrosis, while enhancement attempts to “improve” an otherwise healthy individual.

Unsurprisingly, the concept of genetic enhancement has garnered the most fear and suspicion. The reason for this fear is easy to imagine. On the one hand, genetic enhancement could be used for seemingly beneficent purposes: extending the human lifespan, increasing intelligence, or designing cancer-resistant genes for children. On the other hand, Bernard Rollin, noting pornography’s tendency of “catering to all manner of predilection,” wonders what creatures we would create from such mastery of genetics.2 After all, we could make mythical chimera a reality, build children with specific musical or artistic talents, or even design a worker-class human who possesses great strength, durability, and (most importantly) limited intelligence.

Genetic engineering does not lend itself to simple distinctions. Nevertheless, it is coming and it has the potential to produce or relieve suffering like nothing else in history. Moreover, Christians cannot afford to reject it or dismiss it outright because it deals with something we must affirm: the body.

Christian Theology and Genetic Enhancement

The Christian view of human nature necessarily includes an orientation to perfection. In the Gospel of Matthew, Jesus commands his followers to “be perfect, as your heavenly Father is perfect” (5:48 ESV). He also responds to the rich young man with the condition “if you would be perfect” (19:21). James Keenan interprets this call to perfection as a true goal, not as an asymptotic aim. He writes that since “perfection is the realization of a created thing’s destiny which God has already in germo designed,” the question is not “whether we should pursue perfection, but rather what perfection we are pursuing.” 3

Dignitas Personae, a 2008 document from the Congregation for the Doctrine of the Faith, calls for a measured acceptance of genetic engineering. According to the document, the church may accept therapeutic uses but must reject nontherapeutic uses. Dignitas states that unnecessary enhancement “would promote a eugenic mentality and would lead to indirect social stigma.”4 For one thing, such drastic manipulations (for example, designing a child to be tall, athletic, beautiful, or intelligent) would almost certainly remain out of reach for the lower economic classes. But more fundamentally, Dignitas warns that enhancement focuses on “qualities that happen to be appreciated by a certain culture or society,” disregarding the possibility that “such qualities do not constitute what is specifically human.”5 Christians cannot condone attempts to change human nature. Dignitas allows that both somatic and germ line gene therapy could be morally licit, but it argues that using these treatments for enhancement would probably harm the common good and represent an attempt to usurp the place of the Creator. Acceptance, consequently, is limited to genetic therapy.

But if we believe that God took on human flesh and glorified it in the resurrection, then we must believe in a perfect human body. Paul, of course, informs us that in the resurrection we will have bodies but that they will be spiritual, incorruptible, and immortal (1 Cor. 15:36–44 NABRE). In the end we will have perfect bodies. Yet the Christian belief in the goodness of creation, not to mention our directive to care for the sick, indicates that we cannot simply ignore bodies until the resurrection. Certainly, the harm that genetic enhancement could inflict is qualitatively different than any human beings have previously been capable of producing. Moreover, genetic enhancement cannot expect to fabricate resurrection bodies. Yet it should aim, like medicine always has, at the sort of embodied perfection promised in the resurrection—freedom from pain and death. Therefore, we cannot oppose enhancement without denying our orientation toward perfection.

Genetic Enhancement with and without a Goal

In After Virtue, Alasdair MacIntyre argues that modern moral disagreements stem from the lack of a “shared impersonal standard.”6 For example, a utilitarian might make a well-reasoned argument in favor of torture whereas a deontologist might make an equally well-reasoned argument against it. Although both appeal to an impersonal standard, they do not share the same impersonal standard. They will never agree because they have no common ground. In short, modern thinkers have lost the shared conception of the goal of human nature, or telos, which makes coherent ethical discourse possible. I suggest that much of the discussion of genetic enhancements (both in favor and against) reveals a similar incommensurability arising from the lack of a shared picture of the ideal body. Arguments for and against genetic enhancement are persuasive only if one agrees with the author’s presuppositions regarding the physical form.

First, consider two arguments against genetic enhancement. In The Case Against Perfection, Michael Sandel, a political philosopher at Harvard, argues that genetic enhancement destroys our appreciation of life as a gift. He blames this destruction of appreciation on the motivation behind enhancement rather than on the enhancement itself. Sandel explains that “what the drive to mastery misses and may even destroy is an appreciation of the gifted character of human powers and achievements,” leaving human beings with nothing to affirm except their own will.7 Moreover, positive human characteristics like humility and solidarity require the continuing presence of bodily imperfection, and subsequently, human suffering. Similarly, Erik Parens, a senior research scholar at the Hastings Center, worries that genetic enhancement will lead to “inauthenticity and threats to self-understanding.”8 “Authenticity” here refers to questions such as: What is it that makes me me? If I am depressed should I take Prozac, or is being depressed a fundamental part of my identity?9 Human nature, in other words, is something we each decide for ourselves.10

In arguing against genetic enhancement, both Sandel and Parens rightly point to the dangers of genetic enhancement (e.g., genetic social inequality and privileging arbitrary, ephemeral preferences like hair color or cleavage). Yet each relies on a particular conception of the ideal body to make his argument. For Sandel, human nature requires an imperfect body (namely, one that suffers) in order to appreciate its own giftedness. For Parens, the need for self-determined human nature requires the lack of an ideal body. This ideal body is not a “perfect” body. Both oppose the “perfect” body, that is, a body without “flaws.” But both still rely on an ideal body as normative; both still conceive of a specific form of human embodiment that facilitates (their conception of) human nature. Thus, while both thinkers oppose the flawless body, they rely on the same sort of goal-oriented conception of embodiment as the arguments for perfection that they oppose. However compelling their fears may be—and they are compelling—they are only compelling if one shares their vision of the ideal body.

One finds the same presuppositions in arguments for genetic enhancement. Norman Daniels, a professor at the Harvard School of Public Health, questions the very possibility that an enhanced body could change human nature.11 This fear, in Daniels’s estimation, misunderstands the very concept of human nature. Human nature, for Daniels, is relative; it is the description of the genetic makeup and observable actions of a whole population. Given that most enhancements aim to alter something already within this scope, genetic enhancement does not threaten human nature. And even if a whole population changed, the definition of human nature would simply change accordingly.

Julian Savulescu, a professor at Oxford, defends genetic enhancement as “procreative beneficence,” that is, the choice to have “the best child of the possible children one could have.”12 He argues that if, with all other things being equal, we have the ability to choose what appears to us to be the best life for our children, then there is no rational reason not to do so. Still, although he doubts whether we can truly consider weakness a constitutive aspect of human life, he admits that the best life may contain imperfection. Indeed, Savulescu avoids objective moral judgments: “As rational people we should all form our own ideas about what is the best life. But to know what is the good life and impose this on others is at best overconfidence—at worst, arrogance.”13 Savulescu, like Daniels, seemingly remains open to a variety of human bodies, so long as the body does not impede an individual’s self-actualization. The ideal body, like human nature, is whatever one decides the ideal body should be.

But the only way to say anything intelligible about how we should act is to have a clear view of where we are going.14 MacIntyre explains that classical and medieval thinkers had a threefold ethical scheme: ethics was the device that transformed human-nature-as-it-is into human-nature-as-it-should-be.15 Arguments for and against genetic enhancement only gain traction if one shares the vision of the ideal body that underlies those positions, and it seems that most thinkers are reticent to offer such visions of the ideal body. Admittedly, the authors discussed here did not set out to offer a comprehensive anthropology so much as to point out the potential ramifications of genetic enhancement. Nevertheless, any argument for or against genetic enhancement—for or against changing the human body—presupposes an ideal body that genetic enhancement either strives toward or deviates from. But rather than stating how genetic enhancement relates to an ideal body, arguments form around how the body helps or hinders human nature. By taking this angle, thinkers separate the body from human nature, which leads to a position that either denigrates or idolizes the body.

Indeed, the lack of a goal for the body suggests a predilection toward either Gnosticism or materialism. Gnosticism denigrates the body by seeing it as merely the vehicle through which human nature finds fulfillment—fulfillment takes place in a body, but not as a body; the body is a means to an end. For example, fulfillment might require suffering to inspire compassion or longevity to allow for social accomplishment. The ideal body is immaterial. Conversely, materialism idolizes the body by seeing in it the whole extent of human nature. For example, the good life might require possessing the most rational mind or the greatest strength. Whatever ideal body it aims at represents the amplification of material wants.

Christians, however, must reject both the gnostic and materialist perspectives; we must consider questions of genetic enhancement in light of the perfected body seen in the incarnation and resurrection.

Quo Vadis? Directions from Science Fiction and Balthasar

If we are called to better ourselves by becoming better Christians, we must acknowledge that this position includes (eventually, at least) the bettering of the body. The question, therefore, as Keenan notes, becomes what type of bodily perfection should we pursue?16 What physical qualities should Christians favor? If controlling height and athleticism is foreseeable, then adjusting genes that control our propensity to anger, violence, or addiction cannot be unimaginable.

Dignitas Personae’s distinction between therapy and enhancement is one attempt to delineate a specific goal.17 And while such a distinction is helpful, pushed far enough it falls apart. Few would contest curing genetic diseases like cystic fibrosis, Tay-Sachs, or sickle-cell anemia, but what about deafness, near-sightedness, or lactose intolerance? Lactose intolerance especially throws a wrench in the therapy versus enhancement distinction. Most adults from dairycentric cultures (Northern European descent) produce lactase, the enzyme that enables the digestion of lactose, whereas people from other parts of the world lose this ability as adults.18 So, is lactose intolerance a deficiency or is lactase persistence an enhancement? Similarly, Erik Parens wonders about a scenario in which two boys can expect to grow into shorter-than-average men, one due to a disease, the other due to heredity. Would giving the boys hGH (human growth hormone) to increase their heights be therapy for one and enhancement for the other?19 How can Christians answer this question without denigrating or idolizing the body?

In his science fiction novels Hyperion and The Fall of Hyperion, Dan Simmons presents a world in which all human beings possess technology that grants them control over DNA.20 Yet it is the way different groups use this technology that makes them more or less human. One group, “the Hegemony,” mostly eschews genetic enhancement except for therapeutic and cosmetic changes (one character alters his genes so that he resembles a satyr, which he thinks better illustrates his perverse sexual appetites). Simmons portrays this group as decadent; they are creatively, technologically, and culturally stagnant. In contrast to the Hegemony, he presents the “Ousters,” human beings who have genetically altered themselves to better live in deep space and alien environments. They resemble chimera and other mythological creatures (some, for example, have wings in order to fly on microgravity planetoids). Simmons suggests that these humans—not despite, but because of their alien appearance—better embody human nature, the creative striving toward the infinite. I do not intend to suggest that Christians ought to embrace any and all forms of genetic enhancement. The Ousters’ extreme variations on the human form suggest a certain degree of gnostic libertinism. Nevertheless, Simmons’s novels argue that human beings ought to be a union of body and soul; the body must incarnate the human drive to explore and create no matter what world it is on.

Similarly, the Christian acceptance of genetic enhancement ought to be multifaceted. In Truth is Symphonic, the Roman Catholic theologian Hans Urs von Balthasar explains that we cannot reduce Truth to unison, a mere collection of homogenous expressions. God’s revelation is polyphonous,21 and this diversity best expresses God’s transcendent unity as a harmonious symphony. Indeed, it is this unity that compels individual Christians to follow diverse vocations and still come together as one church. “Maximality,” consequently, is the measure of Christian dogma: “The expression must cause the act of God’s love for us to appear more divine, more radical, more complete and at the same time more unimaginable and improbable.”22 There are an infinite number of ways in which dogma can be expressed because God’s mystery is infinite. Correctly used, dogma will lead one toward this mystery and away from obstacles. Thus, to approach genetic enhancement faithfully, I contend that Christians must apply this maximality criterion to the body.

We worship God with bodies—indeed, as bodies. Just as there are an infinite number of ways in which dogma can express God’s mystery, there are an infinite variety of bodies that can manifest God’s glory. The glorified body of the resurrection is the Christian’s ideal body. We can never hope to achieve it through our own works—no matter what wondrous technologies we devise—yet it remains the body for which we long. We remain free to embody Christian love in diverse ways.

Dignitas Personae distinguishes between therapy and enhancement, preferring innovations that alleviate suffering while rejecting pursuits grounded in vanity. Yet this distinction need not be absolute. A Christian framework of genetic enhancement would not accept every enhancement, but it should recognize the similarity between genetic therapies that cure diseases like cystic fibrosis and genetic enhancements that might render children resistant to diseases like cancer. Both forms of genetic engineering reflect the goodness of creation and our hope for the resurrection.

In this way, too, the criterion of maximality helps Christian acceptance of genetic enhancement avoid moral relativism. We do not need to force a therapy-enhancement dichotomy in order to uphold our belief in absolute good but neither should we should presume to anticipate every use or every context. What is vanity in one situation might save a life in another (we can see this already, for example, in the difference between plastic surgery and reconstructive surgery). The criterion of maximality embraces the polyphony of Christian responses and guides that polyphony to symphonic unity. Indeed, when we apply the maximality criterion to the body, we avoid slipping into a gnostic or materialist mentality and instead find ourselves considering questions of genetic therapy and enhancement with an eye toward how our answers and actions might reflect God’s glory.

We would also do well to remember Christ’s own resurrected body. It still bore the wounds of the crucifixion. If nothing else, this image should disabuse us of any notions that the perfect body is merely a pretty one. Affirming the body means that everything we do with and to our bodies matters. Genetic enhancement, fortunately or unfortunately, just adds another layer of complexity to this truth. No matter how frightening it might be, we cannot run from genetic enhancement without running from our own bodies. There will be no sweeping answers; acceptance of genetic enhancement will require ongoing discernment, but such discernment has always been part of the Christian life.


1. See John Hyde Evans, Playing God?: Human Genetic Engineering and the Rationalization of Public Bioethical Debate, Morality and Society Series (Chicago, IL: University of Chicago Press, 2002), 1–3; 74–77. Evans discusses, among other things, the rhetorically wise choice of those in favor of genetic intervention to use the term therapy when talking about gene transfer, 75. J. Robert Loftis observes that germ line transfer is more “ethically suspect” because of its far-reaching effect to future generations in Loftis, “Germ-Line Enhancement of Humans and Nonhumans,” Kennedy Institute of Ethics Journal 15, no. 1 (March 2005): 58.

2. Rollin, “Genetic Engineering and the Sacred,” Zygon: Journal of Religion & Science 40, no. 4 (December 2005): 949.

3. James Keenan, SJ, “‘Whose Perfection Is It Anyway?’: A Virtuous Consideration of Enhancement,” Christian Bioethics: Non-Ecumenical Studies in Medical Morality 5, no. 2 (August 1999): 105; 108. Italics in original.

4. Congregation for the Doctrine of the Faith, Dignitas Personae: On Certain Bioethical Questions (London, UK: Catholic Truth Society, 2009), 27.

5. Ibid.

6. MacIntyre, After Virtue: A Study in Moral Theory, 3rd ed. (Notre Dame, IN: University of Notre Dame Press, 2007), ix.

7. Sandel, The Case Against Perfection: Ethics in the Age of Genetic Engineering, 1st ed. (Cambridge, MA: Belknap Press, 2009), 27; 100.

8. Parens, “Is Better Always Good? The Enhancement Project,” The Hastings Center Report 28, no. 1 (1998): 8.

9. Ibid., 11.

10. Ibid., 12.

11. Daniels, “Can Anyone Really Be Talking About Ethically Modifying Human Nature?,” in Human Enhancement, ed. Julian Savulescu and Nick Bostrom (Oxford, UK: Oxford University Press, 2009), 25–42.

12. Savulescu, “In Defence of Procreative Beneficence,” Journal of Medical Ethics 33, no. 5 (2007): 284–88.

13. Savulescu, “Deaf Lesbians, ‘Designer Disability,’ and the Future of Medicine,” British Medical Journal 325, no. 7367 (2002): 771–73.

14. MacIntyre, After Virtue, 53.

15. Ibid.

16. Keenan, “’Whose Perfection Is It Anyway?,’” 116.

17. Congregation for the Doctrine of the Faith, Dignitas Personae, 27.

18. James C. Peterson, Changing Human Nature: Ecology, Ethics, Genes, and God (Grand Rapids, MI: Eerdmans, 2010), 7–8.

19. Parens, “Is Better Always Good?,” 3.

20. Dan Simmons, Hyperion (New York, NY: Doubleday, 1989); and Simmons, The Fall of Hyperion (New York, NY: Doubleday, 1990).

21. Hans Urs von Balthasar, Truth Is Symphonic: Aspects of Christian Pluralism (San Francisco, CA: Ignatius Press, 1987), 11.

22. Ibid., 65.