Leon Kass has described himself as a strange man who writes strange and untimely books. Given the intellectual condition of the contemporary academy, this is by no means a bad thing. Trained professionally as a physician and biochemist, Kass has, without formal academic training, taught courses in philosophy and literature for the past twenty“eight years at the University of Chicago. A prolific essayist, he has published books on the proper relation of biology and human affairs, the connection between eating and the perfection of human nature, and the deepest meanings of courtship and marriage. But the real reason why Kass seems so strange today is that he defends the dignity of our given human nature in a world that is transformed almost daily by advances in science and technology.

Life, Liberty, and the Defense of Dignity is largely a collection of reworked, previously published essays on biotechnology”one of which originally appeared in First Things (“L’Chaim and Its Limits: Why Not Immortality?” May 2001). In this book, the Chairman of the President’s Council on Bioethics offers a penetrating and unnerving reflection on how biotechnology’s growing ability to alter our nature fundamentally threatens our dignity as human beings. Biotechnology is, as Kass shows, something of a mixed blessing. It has allowed many of us to live longer and healthier lives, something Kass believes we should be most grateful for. At the same time, some emerging biotechnologies”especially in neuroscience and psychopharmacology”threaten to technologically alter the very face of our humanity. As Kass jarringly puts it in his Introduction, the burgeoning biotech revolution has already brought us to a point where “human nature itself lies on the operating table, ready for alteration, for eugenic and neuropsychic ‘enhancement,’ for wholesale redesign.”

In Kass’ view, this kind of technological enhancement and redesign ultimately will result in the flattening of our souls. By pursuing physical health as the greatest of human goods, we will inevitably end up sacrificing the moral and spiritual goods that give meaning and dignity to our lives. The degraded and dehumanized “Brave New World” of soma and Bokanovskification that Aldous Huxley so vividly described two generations ago seems closer with each passing day.

Western societies have largely been unwilling to face the all“too“human consequences of this looming post­human future. Seduced by promises of even bigger and better biotechnologies in the years to come, we have opted not to think about what is really at stake in the biotech revolution. However, given the recent extraordinary proliferation of biotechnologies, from the completion of the Human Genome Project to our growing expertise in the science of cloning, the time has come for everyone who cares about the preservation of our humanity to recognize what is at stake. In this effort, Kass’ elegantly written and thought“provoking book will undoubtedly be of much help.

Kass begins his book with a reflection on “the problem of technology and liberal democracy.” The two have something of a symbiotic relationship. On the one hand, genuine technological progress presupposes the kind of intellectual and economic freedom that liberal democracy secures. On the other, liberal societies must rely upon technology for assistance in everything from supplying healthy and affordable foods, to sustaining great numbers of people, to developing new and improved military technologies. But technology also creates its own set of problems. Take the case of medical science’s increased ability to push back the frontiers of death. As medical science has helped us live healthier and longer lives, our society has had to struggle to figure out how to take care of a citizenry whose longevity continually increases. Like so many other things in life, technological “progress” is not immune to the law of unintended consequences.

That we view technology as a “problem” at all shows the remarkable extent to which we have internalized modern science’s mechanized and reductionist account of the world. As Kass shows, the greatest problem posed by today’s “brave new biology” does not come from the technologies it produces, but rather from the scientific view from which it is derived. To understand just how deep the problem of biotechnology runs, Kass points out, it must be viewed in the larger context of the revolutionary character of modern science.

Building on the analysis of thinkers such as Leo Strauss and Hans Jonas, Kass offers a rich reflection on the “philosophical foundations” of modern science. The philosophical architects of modern natural science, such as Bacon and Descartes, believed that if science were to successfully minister to human beings’ needs, it would have to alter its basic theoretical posture. Whereas ancient science tried to discover what things are, modern science would now focus on how they worked. Knowledge would be seen as desirable not for its own sake, but because it showed how things could be manipulated to fulfill our many desires. Consequently, modern science would effectively transform our view of nature itself. Nature could no longer be seen as “animated, purposive, and striving,” but as mere “dead matter in motion,” matter that could, and should, be mastered in order to bring about, in Bacon’s famous phrase, “the relief of man’s estate.” The very idea of modern science, as Kass shows, “contains manipulability at its theoretical core.”

Biotechnology is a variation on this larger scientific theme. But it is a particularly dangerous variation, since it allows for the technological manipulation of the manipulator himself. Biotechnology thus paves the way for the complete “medicalization of life and death.” Armed with increased knowledge of how our genes and brains work, we are now in a position to be the subjects of our own manipulations. This is the deceptive promise lurking behind the biotech project. Through neuropharmaceuticals and germ“line therapy, we are told, we will be able to smooth out all of human nature’s rough edges, thus making us completely at home in the world and with ourselves.

If Kass’ diagnosis of the problem of technology is correct, and it rings completely true to this reviewer, there is something deeply unsettling about our current situation. The problem of biotechnology is something that we are remarkably ill equipped to deal with today, if for no other reason than that we are generally unaware of the way that modern science has shaped the very way we see ourselves and the world. What Kass indirectly shows is that even such admirable defenders of human dignity as Francis Fukuyama and James Q. Wilson, who argue that the solution to the problem of biotechnology ultimately lies in enacting sound regulations, radically underestimate the true magnitude of the biotech challenge. And the same could be said about those thinkers who primarily approach the question of biotechnology from the perspective of Pope John Paul II’s rich analysis of “the culture of death.” As insightful and instructive as this analysis is, it too tends to see biotechnology as the source of some particularly dehumanizing practices and not as the product of an all“encompassing scientific view of the world. For liberal societies, unfortunately, there is no quick and easy solution to the “problem” of biotechnology, precisely because it is rooted in the very premises of the modern scientific project itself.

Kass believes that if we are going to confront the challenge of biotechnology seriously and effectively we will have to develop a “more natural biology and anthropology” than the one we have now. Only such a “biologically informed anthropology” can remind us of just what we have to lose through the biotechnological transformation of our humanity. Kass goes a long way in this book towards laying the groundwork for such a biology”and he here builds on some of the arguments he first made in Towards a More Natural Science (1985). But Kass also knows that even a biology that recognizes that human life is lived “not just physically, but psychically, socially, and spiritually” cannot address all of the challenges posed by the brave new future envisioned by biotechnology. As he shows in the book’s final chapter, “The Permanent Limitations of Biology,” no “purely biological” account of man will ever be able to do justice to our lived experience as human beings. There will always be “permanent limits” to what biology can tell us about our lives. The task of defending morality and human dignity and of adjudicating between the claims of the body and soul consequently will “always remain the work of a largely autonomous ethical and political science.” A more natural biology may be able to tell us much about “the loves of life,” but it finally cannot tell us how we should live with life’s different loves.

But because he is aware of the limits of just how far biology can take us, Kass sheds a good deal of light on what is really good and dignified about human life. Indeed, as he points out in a series of chapters on such biotech practices as in vitro fertilization, organ transplantation, cloning, and euthanasia, the cultivation of human dignity actually requires us to live “with and against necessity, struggling to meet it, not to overcome it.” And yet Kass is clearly no Stoic. He sees too much good in human life to accept Stoicism’s claim that we should always remain somewhat detached from the world. Like Pascal and Flannery O’Connor, he thinks that a truly human life requires us to live well with necessity and enjoy those goods such as love and friendship that transcend necessity”though, in contrast to Pascal and O’Connor, there remains a tension in his thought about how these two things finally fit together.

Kass is at his best when reflecting on the two poles of human biological life, birth and death. His treatment of the “human costs” of cloning is second to none. Cutting through the too “familiar political thickets . . . of pro“life and pro“choice,” he shows that the new science of cloning is emphatically not a matter of reproductive rights and technologies. Cloning would allow us to become our own creators, designing our descendants through the technological tyranny of eugenics, thus making possible a kind of evil that is even more perverse than the willful destruction of nascent human life. This is, for Kass, the “political” reason why we should ban human cloning”and he makes a strong case that our initial natural “repugnance” to cloning offers an entranceway to opening up larger questions about the overall desirability of the biotech project.

But he also suggests that what is most pernicious about cloning is that it threatens to extinguish those profound erotic longings that find their fullest expression in human coupling. For cloning is, in principle, corrosive of the natural ties that connect generations and the erotic desire to take part in an act that transcends our own finite existence. The society that condones cloning and denies “the profundity of sex,” Kass argues, has already taken a giant step towards removing eros from human life altogether.

Biotech’s pursuit of what Kass calls “the immortality project” similarly threatens our ability to live a dignified human life. Advances in the use of human growth hormone, stem cells, and the genetic switches that control the aging process hold out the possibility that some day we will be able to radically retard the aging process. But what will be lost if death becomes an increasingly rare and remote occurrence? What will happen to life when we will no longer have to wonder, in the words of the Psalmist, about “the number of our days”? Reflecting on the mysterious connection between mortality and morality, Kass argues that awareness of our mortality adds depth and weight to our lives and points to the grounds of the kind of knowing self“sacrifice that cultivates “the peculiarly human beauty of . . . virtue and moral excellence.”

What temporal immortality really would allow for is the endless enjoyment of the present, a freezing of time in which we would always have the chance to enjoy the goods life has to offer. However, even if such a life becomes possible, it will not bring us real happiness. “Man longs not so much for deathlessness as for wholeness, wisdom, goodness, and godliness.” This is, as Kass observes, the shared message of the wisdom expressed in Aristophanes’ tale of the circle men, Socratic philosophy, and the Bible. As Kass argues, each of these longings”not just the desire for wisdom, as some of Kass’ early writings suggested”points to the fact that our desire for human wholeness cannot be satisfied by any quantity of earthly life.

This last observation points to the real reason why even the kind of biology that Kass develops is finally incapable of supplying the grounds for a wholly satisfying natural ethic. For the truth of the matter is that the type of “wholeness” that biblical religion speaks of is fundamentally different from the wholeness that comes from finding our Aristophanic other half or from the Socratic contemplation of wisdom. It is a wholeness that embraces the good of the entire person, body and soul, and that perfects”not smoothes out”the imperfections of our nature. But if this is the kind of wholeness that we really seek, we will never be truly at home in this world, no matter how well we live with necessity. As Peter Lawler has recently argued, perhaps finally only theological anthropology is capable of giving a humanly satisfying account of how we can really live well in a world where the reach of our natural desires will always exceed our grasp.

Marc D. Guerra teaches theology at Assumption College in Worcester, Massachusetts.