Cloning isn't sexy.

From scotland comes news that a team of fearless scientists has cloned a sheep. One might consider this development one worrisome step for sheep, but more likely it is a very big and very dangerous step for humankind.

"Dolly," as she was christened, was produced in a laboratory where a cell taken from the udder of one sheep was fused with another sheep's egg, from which the nucleus had been removed. The resulting embryo was then implanted in a surrogate mother and brought to term. Dolly is the genetic twin of the sheep from whom the cell was first taken, and her arrival promises benefits in scientific knowledge, agriculture, and medicine.

Dolly caused an uproar in large part because, though theoretically possible, it had long proved technically unfeasible to clone mammals. It is now expected that it is only a matter of time before someone succeeds in cloning the most successful mammal of all - namely, humans. At this point in the conquest of nature by science, it is important to reassert that not everything that can be done should be done. Even Ian Wilmut, the scientist chiefly responsible for bringing Dolly into the world, considers the idea of cloning human beings "offensive..., ethically unacceptable." His instincts are sound. However, a critical observer might also ask why someone opposed to the likely uses of this technology nevertheless decided to set us off on this path.

Some embrace the prospect of manufacturing human life in laboratories. Such thinking seems more a confirmation of the modern trivialization of the meaning of sex than any sober assessment of what is at stake when technology plays so large a part in human reproduction. The Catholic position on these questions is clear-cut - perhaps too clear-cut. Because it draws the line on intervention in procreation at contraception, the church's often astute warnings about the dehumanizing of sex and reproduction have fallen on deaf ears. That's unfortunate, because the human values the church rightly defends in questioning advanced reproductive technologies make its hair-splitting over "barrier methods" and the so-called "contraceptive mentality" seem like mere intellectualized prudery. In reality, much more is at stake.

There are sound moral reasons why human communities have always tied sexual desire to love, and love to marriage, and marriage to the care of children. Neither the extreme view demanding that every sexual act be "open" to procreation, nor the modern presumption that we should be free to desexualize and depersonalize the act of procreation is the best way to promote human flourishing. But where to draw the line along the continuum of interventions is difficult. In the acceptance of each new technology - artificial insemination, in vitro fertilization, surrogate motherhood - a logic of justification is advanced that makes the next moral hurdle seem lower still. Yet as Dr. Wilmut's own trepidation attests, there is widespread uneasiness over giving scientists and potential DNA donors the ability to determine the entire genetic make-up of new human lives. Cloning, with the genetic manipulation and engineering it heralds, may be a line even many who champion "reproductive freedom" will not want to cross.

Still, it is argued that clones ought to be considered little more than "delayed twins." That is true, in a strictly genetic sense. Certainly identical twins occur in nature. But why should anyone be allowed to determine the entire genetic identity of another person? Granting such power over someone else's life - even the life of one's own offspring - is an unwarranted circumscribing of individuality and human possibility. We simply don't have the right to decide such things for others. Parents are entrusted with the lives of their children; they are not the owners or determiners of those lives. As Daniel Callahan has written (New York Times, February 26, 1997), cloning "would be a profound threat to what might be called the right to our own identity."

Human cloning would play havoc with notions of parenthood, kinship, the distinct dignity of children in regard to their parents, and perhaps even the sanctity of life. The possibilities for mischief seem endless, and endlessly dizzying. A woman could, for example, give birth to her own twin. As with justification for most reproductive technologies, the desire of an infertile couple for a genetic child may prove to be the most compelling reason for resorting to cloning. Infertility can be a terrible personal loss. Still, infertility is not sufficient justification for any and all means of bringing a child into the world. Cloning would represent yet a further commodification of procreation; in its asexual method of reproduction and the genetic asymmetry of the child produced, cloning further relativizes the most fundamental of human relationships: that of wife and husband and parents and children. Technological wizardry must not be allowed to undermine monogamous marriage and the biological family. Science and technology should serve the common good, not its own self-aggrandizing imperatives or mere individual desire.

When it comes to cloning, we are a bit like a gardener who thinks she can manage the ecology of an entire forest. There is too much we do not know, too much we can never know. Worse, in almost every respect - from the discarding of "surplus" embryos to the possible creation of genetic monstrosities - cloning requires that we regard another human being as a means to an end, and not as an end in itself. Indeed, the very attempt to clone humans constitutes experimentation (it is not a medical procedure) on someone who is incapable of giving consent, a violation of the most fundamental principles of medicine and science. In sum, like abortion and euthanasia, cloning human beings moves us a step closer to an openly utilitarian definition of human dignity and life.

Justified in the name of scientific progress and humanitarian relief, cloning will be a powerful temptation. Yet the intuition that tells us there is something inherently inhuman in the laboratory production of human beings is sound. Science and technology enable us to transcend our physical limitations, but in doing so we run the risk at a certain point of betraying our true natures. In the creation of children it is important that we prize our full, embodied humanity, and not just one aspect of it. When it comes to separating reproduction from human sexuality, the siren call of scientific progress is largely a ruse. The kind of control over human life and destiny promised by these new reproductive technologies is far too potent to be left in the hands of scientists or anyone else. As our brave new world of self-creation unfolds, we must guard against progress in the name of humanity that in fact dehumanizes.