When people remember the 1960s they usually think of Vietnam, cultural upheaval and assorted liberation movements. But the ’60s should also be remembered as the time when postwar medical technology blossomed. The decade witnessed the advent of kidney dialysis, organ transplantation, the birth-control pill, intensive-care units, the artificial respirator, prenatal diagnosis and the first glimmering of the genetic revolution. Together, these may be the real long-term legacy of the era.

While hardly the most important issue then, the possibility of human cloning was debated during the ’60s. Tadpoles had been cloned, and there was every expectation that humans soon would be. While this prospect brought a shudder to most people, a few scientists—among them the Nobel laureate geneticist Joshua Lederberg—were not put off. They welcomed the possibility as a sign of progress.

Not so Leon R. Kass, who in 1966 was a young scientist at the National Institutes of Health. In a letter to the Washington Post he challenged Lederberg, thus setting off a public debate on the subject. More than 30 years later, human cloning has yet to take place, but Kass has not let up. Now a professor serving on the Committee on Social Thought at the University of Chicago, he was appointed chair of the President’s Council on Bioethics in 2001. Kass ably led the council members in a long debate on cloning, with the result that earlier this year they came out in opposition to human cloning but divided on the use of cloned embryos for research purposes. For Kass, however, cloning of either kind is a fundamental assault on our humanity and our dignity.

In 1969, at the suggestion of theologian Paul Ramsey, I asked Kass to help my colleague Willard Gaylin and me establish the Hastings Center, which became the world’s first research group devoted to the then nonexistent field of bioethics. He agreed, worked on many of our projects and served on our board of directors for many years—and as time went on began muttering about the dangerous direction bioethics was taking, hinting at times that the center had become part of the problem, not of the solution.

In light of this history I was surprised to be asked to review this book. Well, the editor said, it’s because I might in fact differ from Kass in interesting ways. True enough. What Kass and I share is well articulated in the book: the conviction that bioethics can play an important role in examining the meaning and direction of biomedical research and technological innovations. It can change the way we direct critical institutions, think of human nature and live our lives.

Much is at stake for many of our traditional moral and cultural foundations, particularly those “self-evident” truths proclaimed in our Declaration of Independence. The American romance with science means that, as Kass writes, “we adhere more and more to the scientific view of nature and man, which both gives us enormous power and, at the same time, denies all possibilities of standards to guide its use.” What standards we still have are being assaulted by an encircling and only lightly resisted scientific ethos, assisted by a liberal individualism ill prepared to deal well with questions about our common future rather than our private interests. In the early days bioethics focused on such larger issues, but the field was in time overtaken by an interest in what can be called regulatory bioethics: the protection of research subjects, the advancement of patient rights, and the devising of procedural guidelines for end-of-life care, for instance. Those were the issues that made it into the courts and the media. Americans have found them far more congenial to debate than the kind of deep inquiry Kass has long called for.

I hope that Kass’s book will move his cause along. Its great strengths are its clear and pungent prose, its passion, its seriousness, its uncommon perspective and the many fresh insights it brings to familiar, much debated topics. Consisting in part of earlier essays, the book ranges over a broad swath of bioethical issues, from the beginning to the end of life, with a particular interest in the moral trajectory of science and technology, reproductive biology, and genetics. Of these matters, Kass writes that “human nature itself lies on the operating table, ready for alteration, for eugenic and neuropsychic ‘enhancement,’ for wholesale design. In leading laboratories, academic and industrial, new creators are confidently amassing their powers, while on the street their evangelists are zealously prophesying a posthuman future.”

At the core of Kass’s concern is human “dignity.” He is worried about threats to our “humanity,” and the hazards of a reductionistic approach to human life and its manipulation for hubristic and unreflective ends. The language of “dignity” has been much stronger in European public life and law than in the U.S. We seem to find “rights” a more congenial mode of discourse. Yet Kass’s pushing of this concept raises the important question of how we best might talk of these grave and serious matters.

Kass is hard on contemporary philosophy, faulting it for its rationalistic bent, its failure, as he says, to deal with life on the ground. In any case, philosophy has not of late aspired to the kind of grand and profound wisdom that Kass is seeking. The language of rights might do the job, but it is saddled with an emphasis on negative rights (i.e., our right to be let alone), and it is both too legalistic and overused as a quasi-moral language.

But the concept of “dignity” has many drawbacks as a contender for the transcendent, universal motivating ideal. “The first trouble with ‘dignity,’” as Kass himself concedes, “is that it is an abstraction, and a soft one at that.” His attempt to clarify the concept is not very successful, mainly relying on the word’s etymological roots and on different dictionary definitions. But these are bewilderingly diverse, particularly if one is looking for a term with both ethical and political force. A major part of the problem is that though Immanuel Kant wrote about dignity in the 18th century and the word was in use even earlier, strong efforts to elucidate and work with it have not been made (as have been made for, say, the notion of human rights, the subject of innumerable books, essays and court cases).

Kass’s ambitious use of the term—as a clear standard for determining what is right and wrong and in keeping with our nature, and for judging the course of biomedicine—strikes me as impossible for such a soft and abstract concept. To make matters worse, Kass construes “dignity” to be an “aristocratic” idea and speaks, in a somewhat slighting way, of the possibility of “democratizing” it. If the idea of dignity needs that kind of marketing or selling, then as a politically useful concept it is dead on arrival. Since in other places, however, he makes a strong case for human equality, which is not a function of particular traits or virtues, perhaps I am reading incorrectly what he means by “democratizing.”

My objection is not to Kass’s effort to find a way of characterizing the inherent value of human life and certain important human characteristics, but to his reliance on “dignity” to make his case. For all of its shortcomings, mainly vagueness and the tendency to invite contention, the language of costs and benefits, or risks and benefits, or good and bad consequences ( a language whose value Kass minimizes) does a reasonably good job of helping us make prudent judgments. My basis for flatly opposing reproductive and research cloning is that it offers too little human benefit at the cost of too much likely harm, not that it is an offense against human dignity.

Our culture lacks a way of talking effectively about the ultimate value of human life, or making large judgments about what is good for human beings in the long run. We do it well enough when we debate nuclear weapons, environmental degradation, world hunger or totalitarianism. There we have a fund of experience to draw upon. But with most of the newer biomedical and genetic technologies we have little or no direct experience, only speculation.

Kass would like nature to serve as some kind of moral guide, but he does not develop how that could best be done. Referring to C. S. Lewis’s much-cited claim in The Abolition of Man, Kass writes that if “man’s so-called power over nature is, in truth, always a power exercised by some over others with knowledge of nature as their instrument, can it really be liberating to exchange the rule of nature for the role of arbitrary human will?” The idea that the conquest of nature is inevitably used as a means to gain power over others is at best an unhelpful half-truth. The invention of the wheel and the plow don’t easily fit that description, and the Internet, it turns out, often subverts autocratic power. And just what is “the rule of nature” regarding medicine and biomedical technologies? Surely Kass does not mean that whatever nature brings to the human body is acceptable (indeed, he praises much of medical progress). His meaning here remains obscure.

In any case, whether one bases one’s decision on risk-benefit calculations or on intuitions about human dignity, to decide how to deal with new technologies is to venture into terra incognito. But Kass is utterly right that, despite our ignorance about the final outcome, we must recognize biomedical developments as grave matters and be ready to stop them when necessary. That will not be easy, especially if we accept his diagnosis of our present situation. “The technological approach to life,” he writes, “. . . is tragic [but that] does not mean our life must inevitably be tragic. . . . Everything depends on whether the technological disposition is allowed to proceed to its self-augmenting limits, or whether it can be restricted and brought under intellectual, spiritual, moral and political rule.” And he would have us do so “without undermining biomedical science or rejecting its genuine contribution to human welfare.”

True though this is, many of the possibilities Kass foresees may come about inadvertently, not as the result of arrogant scientists and their shills engaged in creating a posthuman future. Improved memory for all of us, for example, is most likely to come from efforts to treat the loss of memory in Alzheimer’s or other dementias. Efforts to improve the quality of life of the elderly will almost certainly continue lengthening life as an unintended by-product (the main increases in longevity for those beyond 65 have been an offshoot of higher socioeconomic standards of living and disability-oriented technologies). Demographers have shown that, based on historical trends, it is plausible to project an average life expectancy of 100 even if we don’t lift a finger specifically to bring about that result.

A major point in Kass’s arguments against research cloning is that it is a classic slippery slope, allowing the development of the biological tools necessary for reproductive cloning, which is sure to happen when those tools are in place. Yet the biomedical sciences, which he agrees we should not undermine, are full of slippery slopes, most of them accidental and unforeseen. We may on occasion be able to control the posthuman scientific devils we foresee, but those that we do not foresee have as good or better a chance of doing us in. Moreover, there is a strand of the biomedical community that celebrates risk-taking. The name of James D. Watson, our most celebrated geneticist, comes immediately to mind. Ethical hand-wringing and doomsday scenarios are said to slow progress. The environmental movement makes use of a “precautionary principle” to deal with environmental risks. The biomedical sciences have made no move in that direction, but Kass’s book might help us to do so.

Unfortunately, there are many features of the book that will alienate scientists and bioethicists, as well as many liberals, who will be put off by Kass’s at times cavalier treatment of their commitments. “If I have written too polemically, it is only because of a passionate concern that we consider before it is too late whether we truly know what we are doing,” Kass says. But a little polemic goes a long way, and there is more than a little of it in his book. Worse, this polemic is marred again and again by a harsh moral rhetoric directed against unnamed bioethicists and scientists accused of driving us to a posthuman future. For example, the chapter on the “right to die” is not helped by Kass’s assertions that “many” of its proponents “are either too ashamed or too shrewd to state their true intentions,” which are to decrease the cost of caring for the “irreversibly ill and dying . . . and to change our hard-won ethic in favor of life.”

It is a toss-up whether scientists or bioethicists will be most offended by the way they are characterized in the book. Of genetic therapists and technologists, Kass writes that, despite their appearance of eschewing “grandiose goals” and simply aiming to relieve suffering, “let us not be deceived. Hidden in all this avoidance of evil is nothing less than a painless, suffering-free and, finally, immortal existence,” a goal he finds wrongheaded and dangerous. His harsh treatment of the therapists and their camp followers (including the earlier National Bioethics Advisory Committee) might usefully be compared with the irenic way he handles criticisms of his own Jewish tradition and recent Jewish commentators on the same matters.

“Jewish commentators on these and related topics in medical ethics,” he writes, “nearly always come down strongly in favor of medical progress and on the side of life—more life, longer life, new life. They treat the cure of disease, the prevention of death and the extension of life as near-absolute values.” In short, it turns out that just those values Kass excoriates in our current medical culture have existed for a long time, and in a venerable religious community. I should add that he tries to show that both cultures are wrong, and it is fitting that he do so. But the more irenic tone he uses for speaking to his own Jewish community might win some of them over, while the more harshly attacked “genetic therapists and technologists” are likely to go away mad.

Then there are the bioethicists, to whom Kass gives a fair amount of space, mostly negative. He praises me and a few others for bringing to early bioethics “the recognition that beneath the distinctive issues of bioethics lie the deepest matters of our humanity.” We did try to do that, and my greatest disappointment in bioethics is that it has been, at best, only fitfully successful in carrying on those inquiries. It is easy enough, moreover, to find some bioethicists advancing morally hazardous views. Peter Singer is a good case in point.

Yet Kass presents a distorted, out-of-date picture of the present field of bioethics, which has changed much over the past three decades. He says that a particular moral theory called “principlism,” which emerged in the mid-1970s—embracing the principles of autonomy, nonmaleficence, beneficence and justice—came to characterize the field “according to the profession’s own self-declaration.” There was no such declaration and no professional body even existed that could claim to speak for all of us. Even now, there is not, as Kass says, a “national professional society that accredits members of the guild.” More important, by the end of the 1980s principlism was a theory widely joked about and rejected as the “Georgetown mantra” (it was emphasized at the Kennedy Center for Bioethics at Georgetown University). In addition, its leading principle, autonomy, has been under constant criticism for well over a decade.

Bioethics is also said by Kass to be abstract and removed from ordinary life. But for at least a decade most bioethicists have agreed with that criticism, and this has spawned a lively interest in the social context of moral problems and decisions, and in the kind of daily life in which they manifest themselves. As for the claim that bioethicists are indifferent to the possibility of a new eugenics, a reader might consult Troy Duster’s Back to Eugenics.

Far overshadowing those reservations, however, is the fact that Kass is one of the most stimulating people I have ever known. His many skills are on display in this provocative book. If those who cannot imagine reading a book by such a hard-shell conservative will put aside their prejudices, they are likely to be sometimes annoyed and exasperated, but they will learn a great deal. They may come to take seriously Kass’s central argument that these issues are crucially important and may come to agree that they are critical for the human future, as he so tellingly contends.