“Since Copernicus man has been rolling from the center toward X.”
—Friedrich Nietzsche

Near the beginning of his Oration on the Dignity of Man (1486), the great Italian humanist Pico della Mirandola pictures the creation of the world. The heavens and earth are formed, and the earth is endowed with its complement of plants and animals. Yet when all is done, the divine craftsman still wants someone to behold the splendor and ingenuity of his work. He thus sets about creating man. But since all the “archetypes” have been used, and since every fixed place in the plan of creation has already been filled, he makes man a creature of “indeterminate nature,” a creature who would have to depend upon freedom to define himself and his place in the world. “Neither a fixed abode nor a form that is thine alone nor any function peculiar to thyself have We given thee, Adam,” Pico has God intone.

Pico’s version of Genesis is full of the confidence and heady optimism that fueled the Renaissance. Freedom, power, the notion that man has no “set limits” or given nature, that he creates his nature and his place in the world—these ideas set Pico in opposition to the tradition that he had inherited. They also prefigure the intellectual revolutions of the sixteenth and seventeenth centuries, the revolutions of “the new science,” of Copernicus and Galileo, of Bacon, Newton, and Descartes. In seizing the freedom to determine himself, man at the same time begins to assert his freedom in order to take charge of nature.

It would be difficult to overestimate the importance of this shift. Since the time of Aristotle science had been essentially a contemplative matter; truth was conceived as a stable order that man strove to behold. But in the modern age, science became fundamentally aggressive, inseparable from the project of grasping and manipulating nature—including man’s nature—according to human designs. Instead of opening himself up to nature’s secrets, man now strove to reconstruct those secrets by active intervention. Francis Bacon’s celebrated declaration to the effect that “knowledge is power” typifies the new approach.

Nowhere was this new approach more dramatically crystallized—or more systematically worked out—than in the philosophy of Descartes, who can with some justice be considered the architect of modern science. In a famous passage near the end of the Discourse on Method, Descartes heralds a “practical philosophy” that, unlike the speculative philosophy of scholasticism, “would show us the energy and action of fire, air, and stars, the heavens, and all other bodies in our environment, as distinctly as we know the various crafts of our artisans, and could apply them in the same way to all appropriate uses and thus make ourselves the masters and owners of nature.”

To make ourselves the “masters and owners of nature”: that is the goal. The index of knowledge is here not theory but power and control. Like the artisan, we really know something when we know how to make it. And among the benefits that Descartes envisioned from his new philosophy was a more efficacious medicine: by understanding the principles of nature, Descartes wrote, we might hope to control man’s physical nature, freeing him from “an infinitude of maladies both of body and mind, and even also possibly of the infirmities of age.”

The staggering success of modern science and technology—including modern medical technology—underscores the power and truth of Descartes’s vision. What we call the modern world is in a deep sense a Cartesian world, a world in which man has exploited the principles outlined by Descartes to remake reality in his own image. But there is a dark side to this mastery. Increasingly, one confronts the fear that man, despite his technical prowess, may be enslaved by his dominion over nature. Nor is this fear confined to the effects of our science, to the lethal arsenal of weapons and pollutants that human ingenuity has scattered over the face of the earth. Equally (if more subtly) fearsome is the crisis in values that modern science has helped to precipitate. Committed to the ideal of objectivity, modern science requires that the world be silent about “values,” about meaning in any human sense, for it requires that everyday experience be reduced to the ghostly, “value-free” language of primary qualities and mathematical formulae. While this language has given man great power over the world, it cannot speak to him of his place in the world.

The staggering success of modern science and technology underscores the power and truth of Descartes’s vision.

Hence, as Nietzsche saw with devastating clarity, the other side of our commitment to the ideal of objective truth is nihilism. “All science,” he wrote in the Genealogy of Morals, “has at present the object of dissuading man from his former respect for himself, as if this had been nothing but a bizarre conceit.” Since the truth for Nietzsche—as for us as well—means first of all objective, scientific truth, everything that binds us to the world as wanting, lacking, embodied creatures-sexual attraction, beauty, pain, hunger, etc.—must be denied the title of truth. It was precisely this insight that led Nietzsche to insist that “the value of truth must for once be experimentally called into question.”

Leon Kass’s Toward a More Natural Science is perhaps best seen as continuing the philosopher’s questioning of the value of scientific truth. Like Nietzsche, Dr. Kass, a medical doctor and Luce Professor of the Liberal Arts of Human Biology at the University of Chicago, takes as his theme “the relation between the pursuit of knowledge and the conduct of life.” Skeptical about “the reasonableness of divorcing science from ordinary experience,” Dr. Kass writes in his introduction that “the promise and peril of our time are inextricably linked with the promise and peril of modern science.” Yet it is important to emphasize that he aims not to subvert but to supplement science. He does not wish to diminish the achievements of science but “to point out that the teachings and discoveries of science are at best partial—indeed, partial in principle.”

Unlike those who would blithely reject technology, then, or who would have us view science as a particularly severe form of poetry, Dr. Kass’s reflections proceed from a practicing scientist’s ingrained respect for the authority of scientific discourse and its practical achievements. Hence, he attempts to dissociate himself from those who would have us invest the term “nature” with a quasi-mythical significance. “‘Natural’ and ‘more natural’ mean here only ‘true (or “truer”) to life’ as found and lived,” Dr. Kass insists. “The careful reader will find here neither romanticism nor natural law, and no exhortations to eat organic foods.”

Written over the course of some fifteen years, the thirteen essays that compose Toward a More Natural Science do not advance a single, consecutive argument. Instead, they comprise a series of meditations on the tasks of medicine, the limits of science, and the fate of morality in a culture increasingly dominated by a rational, scientific worldview. Along the way, Dr. Kass also offers us numerous reflections on contemporary culture that, taken together, constitute something of a brief against the widespread assumption that cultural relativism must have the last word. “In our tolerant age,” he writes, “we are reluctant to declare another culture’s beliefs less worthy or true than our own. Indeed, we are generally quick to criticize as ethnocentric any of our passionately held beliefs—except, of course, for cultural relativism itself, a belief, we generally forget, that is itself culture bound.”

Influenced especially by the work of the eminent ethicist Paul Ramsey and by Hans Jonas’s essentially Heideggerian critique of science and technology, Dr. Kass argues against the purely utilitarian, instrumental view of medicine—and of man—that modern biology, with its commitment to “value-free” inquiry tends to foster. In particular, he argues “against the use of some technologies, and even more, against the unexamined belief . . . that all biomedical technology is an unmixed blessing.” It is not hard to come up with examples of the sort of thing Dr. Kass has in mind: from the artificial prolongation of life to developments in genetic engineering, modern biomedical technology confronts us with a host of ethical quandaries. At bottom, his task is to undermine the ethic that proclaims: If it can be done, it may be done. “We must,” he writes, “all get used to the idea that biomedical technology makes possible many things we should never do.”

The “more natural” science announced in the book’s title tokens a science that is not in thrall to the reductive ideal of objectivity. “Ultimately,” writes Dr. Kass,

Dr. Kass begins by inviting us to think through some of the moral and philosophical dilemmas that modern biomedical technology poses. In vitro fertilization and surrogate motherhood, the abortion of genetically defective fetuses, organ transplantation, behavior modification through drugs or surgery, artificial prolongation of life—are such practices morally neutral, to be accepted without question as the results of inevitable technological progress? Or, by challenging our conception of what it means to be human, do they themselves demand challenge? To put the problem more generally, need we revise, our understanding of ourselves in light of the new powers that technology has granted us? Or does this threat to our traditional self-understanding require that we rethink our commitment to modern science and technology?

Dr. Kass’s main point will not be entirely unfamiliar. “In the end,” he writes, “the price of relieving man’s estate might well be the abolition of man . . . . We are witnessing the erosion, perhaps the final erosion, of the idea of man as something splendid or divine, and its replacement with a view that sees man, no less than nature, simply as more raw material for manipulation and homogenization.” But because his discussion focuses on the way modern biomedical technology has intervened in our lives, Dr. Kass’s argument assumes a special immediacy and pathos. For while we live in a world transformed by technology, it is chiefly through medicine that technology impinges directly on our bodies, challenging many traditional notions about the limits of human nature. Since “everything is in principle open to intervention,” Dr. Kass observes, and

Toward a More Natural Science is a reflection on the significance of this loss of limits and standards. It is also a search for new criteria to guide medical practice and, ultimately, ethical thought. What Dr. Kass seeks is a medicine concerned as much with ends as with means, as much with values as with techniques. He envisions “a newer and more natural biology, one truer to experience with room, perhaps, for morality and humanity within.” Thus while Dr. Kass remains close to Nietzsche in his conceptual foundations, he departs from him in his hope of resuscitating traditional values. Where Nietzsche called for the transvaluation of all values and looked to man in his radical freedom to re-create himself, Dr. Kass hopes to reinvigorate a very traditional image of man by critically examining the philosophical foundations of modern science. This is evident in the way Dr. Kass poses the problems he discusses. “What, for example,” he asks,

These are of course exceedingly complex questions. And, as Dr. Kass acknowledges, we contrive what answers we can not so much on the basis of “facts” as on the basis of a prior moral commitment, a sense of how man fits—and should fit—into the world.

Dr. Kass’s own sense of these things is deeply traditional: “Man is defined partly by his origins and his lineage,” he asserts; “to be bound up with parents, siblings, ancestors, and descendants is part of what we mean by human. By tampering with and confounding these origins and linkages, we are involved in nothing less than creating a new conception of what it means to be human.” “What is the significance,” he asks, “of divorcing human generation from human sexuality, precisely for the meaning of our bodily natures as male and female, as both gendered and engendering? To be male or to be female derives its deepest meaning only in relation to the other, and therewith in the gender-mated prospects for generation through union.”

That such questions are not merely academic is shown in the press everyday—in the recent story in The New York Times, for example, about the war against pornography waged by the radical feminist Andrea Dworkin and her “mate” John Stoltenberg. Expressing the noble desire for a world in which gender differences were not the basis for power differences, Mr. Stoltenberg went on to reflect, “in fact, I could really do without gender.” Could he really? What would it mean for a creature who is essentially sexual to “do without gender”? Is gender an “accidental” quality—like the color of one’s hair, or one’s taste in wine? Or consider the popular notion that, as Dr. Kass puts it, “a person has a right over his body, a right that allows him to do whatever he wants to it or with it.” Do we really believe that? Would we want to say that a pregnant woman had the “right” to injure a fetus deliberately—by taking a drug she knew to be dangerous, for example? Does our “right” over our own body extend so far that we may deliberately injure ourselves if we wish? Such questions point to the thorny ethical problems that Dr. Kass grapples with in this book.

Unfortunately, one serious impediment to considering many of the issues that Dr. Kass raises is that they are so fraught with ideological baggage that simply to pose them as questions is to risk raising political hackles. Consider only the problem of abortion. Dr. Kass limits his discussion to the ethical grounds for aborting genetically defective fetuses. In brief, he argues that a policy of aborting genetically defective fetuses conflicts with the Constitutional guarantee of equality. But with admirable frankness, he admits that

Nevertheless, it remains true that for many even to question the moral status of abortion—to say nothing of its legal status, which is a separate issue—is tantamount to taking a stand against it.

To my mind, Dr. Kass displays both great resoluteness and delicacy in his treatment of such issues. For his real interest centers not on the desirability of this or that medical practice but on “some large, enduring, and most difficult questions: the nature of justice and the good community; the nature of man and the good for man.” Now Dr. Kass has obviously set himself a daunting agenda here, especially in an age that is skeptical of the very intelligibility of notions like “the nature of justice” or “the nature of man.” But while he does not always escape the portentousness that such great questions are wont to elicit, it is a testimony to his thoughtfulness that his book succeeds in articulating a powerful challenge to many cherished assumptions about the role of medical science in our lives.

But any book that questions as deeply as Toward a More Natural Science does will itself invite question. I suspect that many readers will dismiss Dr. Kass’s arguments on political grounds, and this is a pity because the issues he raises transcend the vacillating pieties of ideological fashion. Unfortunately, his occasionally preachy tone will not help him on this front: there are many statements that, taken out of context, might suggest that he is far more programmatic in his views than I believe he is. Further, Dr. Kass is sometimes given to speaking in absolutis-tic, almost Platonic terms. In his essay on “The End of Medicine and the Pursuit of Health,” for example, he justifies excluding many items from medical practice—including, by implication, abortion—by appealing to “the inner meaning of medicine.” But is there an “inner meaning of medicine”? Whatever our position on the issues that Dr. Kass raises, mustn’t we insist that the “inner meaning of medicine” is determined conventionally, culture by culture, that “medicine” means what its day-to-day practice mandates?

And, more seriously, we must also question Dr. Kass’s vision of a “more natural” science. He dreams of a science that could “help us to encounter the mysterious, rather than to explain it away,” that could help to restore us “to our proper place within nature’s kingdom, from which we have exiled ourselves in our audacious, not to say hubristic, project to master and possess it.” Granting our audaciousness, hubris, and exile, is it the task of science to remedy them? Should we look to science—as Dr. Kass suggests we should—to “provide some standards for moral and political questions”?

Dr. Kass again and again appeals to the richness of “the phenomena”—the richness of lived experience—to counter the reductive, objectifying tendency of modern science. He asks us to attend with fresh eyes to the appearances of nature, to the beauty and order of the world around us as it presents itself to our senses. Arguing against science’s “deliberately abstracting from the world of ordinary experience,” he hopes to find “humanly meaningful clues from nature,” to rediscover some connection between “nature and good.”

No doubt we would all profit by attending more carefully to nature’s gorgeous panoply. But whether we would then discover some lost connection between nature and the good is another question. Nature does indeed speak to us; but does she provide legible clues to our moral duty? Dr. Kass himself disavows the notion that “precise rules of conduct [might be] deducible from even the fullest knowledge of nature— no sensible person holds that such rules can be simply ‘read off’ from the natural record.” But he advances the only slightly less questionable theses that “the ethical, rightly considered, might be integral to the natural, . . . [that] the natural, rightly understood, might even provide some guidance for how we are to live.”

Dr. Kass’s suggestion rests mainly on his quasi-Kantian arguments for viewing nature as a purposive, well-ordered whole. But I am not sure that his arguments here are convincing. One problem is that nature speaks with many, often contradictory voices: the behavior of the black widow spider toward her mate (she eats him) is no less natural than the gentler lessons that Dr. Kass adduces. And at times he seems to go beyond Kant by hinting that the sense of design we impute to nature is not simply a subjective necessity of our mode of thought but is somehow inherent in nature herself. In a way this is not surprising. Kant noted that teleology “finds its consummation only in theology,” that our discovery of design in nature issues in a tendency to assume a supreme designer. And there is, I believe, a kind of covert theology lurking behind Toward a More Natural Science, especially in the passages dealing with teleology. I doubt, in fact, whether it would have made much difference to Dr. Kass’s main point if those theological tenets were made overt. But, especially in a book on the effects of modern science, it is disconcerting to sense such presuppositions playing themselves out, as it were, in the background.

In any case, the real task is not to make science “more natural” in Dr. Kass’s sense but to realize that the explanations of science are, as he himself puts it, partial in principle. The antidote that Dr. Kass seeks to the dehumanizing effects of modern science will not come from within science; it is not to be accomplished by making science more “humanistic” or more sensitive to man’s moral nature. Science is not and cannot be a respecter of morality. Nor can it withdraw from the ideal of objectivity without at the same time abdicating its authority. Rather, the antidote will come—if it comes—from us as social, political beings, not as scientists; for it is precisely as social and political beings that we must decide upon the ends and goals that science pursues with such frightening singlemindedness. Not that this is a simple task. But it is we, not our science, who need to be less reductive, more open to the texture of reality. For it is we, not our science, who determine the kind of world we want to live in, and part of that determination is deciding on the role that science and technology are going to play in our lives.

Dr. Kass describes his book as “an invitation to reflection”.

Dr. Kass describes his book as “an invitation to reflection”: “[I] mean to provoke questions, not solve problems,” he tells us. And Toward a More Natural Science is surely at its best when it preserves its probing, interrogative stance. But it would be misleading to pretend that Dr. Kass maintains a dispassionate attitude throughout his inquiry. “Is our growing dominion over living nature compatible with respecting our own given nature?” he asks, communicating a resounding “no” in the very formulation of the question. But just this is the question: do we have a “given” nature? Perhaps, as heirs to Pico’s Adam, we are charged with re-creating ourselves—and nature—as we see fit? Perhaps we should strive for “a new conception of what it means to be human”? After all, one might ask, why should we shackle ourselves with a traditional conception of man that has bred prejudice and inequity? Perhaps Nietzsche was wrong to suggest that since Copernicus man has been rolling from the center toward the abyss; perhaps he is merely on his way toward a higher, freer conception of man—an Übermensch, as Nietzsche himself would have put it.

Clearly, Dr. Kass is dubious. At stake is nothing less than the traditional image of man as essentially finite, mortal, embodied, tied to others by birth, culture, and a given sexuality. There is no doubt that the Promethean ambitions of modern science, especially modern medical science, challenge that conception of man with a host of problems for which there are no easy answers. Still, it behooves us to ponder them. For as Socrates reminds Glaucon at the beginning of The Republic, “It is no ordinary matter we are discussing, but the right conduct of life.”