by Richard M. Doerflinger

Why do Christians oppose human cloning?

It's a fair question. Sheep, cattle and other animals have now been "replicated" by the cloning procedure called somatic cell nuclear transfer. An unfertilized egg has its nucleus removed or inactivated, and replaced with the nucleus from an animal's body cell. This nucleus, containing the animal's full genetic makeup, is stimulated to interact with the egg, and a new embryo develops that is genetically identical to the animal providing the body cell. Scientists say the technique can be useful for animal breeding and medical research — and the Catholic Church does not object, as long as the norms against mistreating animals in research are respected.

Yet the situation is very different when this technique is proposed for humans. Catholics and other Christians are in the forefront of the effort to ban human cloning. Supporters of cloning even accuse us of imposing our religious beliefs on a diverse society in this debate.

That charge is false and unfair. Public sentiment against all human cloning is strong and transcends the usual political and religious categories. But the question still remains: Why should Christians, in particular, be so strong in their opposition?

Cloning supporters have proposed one answer: Catholics and other Christians oppose cloning because they are afraid of science and technical progress. But this is false. Catholic tradition honors natural reason and the sciences, unless these disciplines overreach themselves by claiming there is no truth beyond them. Catholics tend to see new technology as good in itself, or at least morally neutral — something that can be turned to good or evil depending on how and why it is used. But our tradition insists on the dignity of the human person and on the need to respect that person's basic human goods — the first and most basic of which is life itself. This is where a true answer begins.

Cloning as a Threat to Life

Cloning may seem like a new way to create human life, not destroy it. But a closer look reveals its darker side.

This technique can be used for two purposes: to produce a live-born child (so-called "reproductive" cloning), or to create human embryos to be destroyed in medical experiments (so-called "therapeutic" cloning — more accurately called research cloning, since therapies may never come from these experiments).

Animal trials indicate that any attempt to use human cloning for reproduction will have many victims. Well over 90% of cloned embryos miscarry or are stillborn. Dolly the cloned sheep was the sole survivor out of 277 attempts. Those few who survive to birth have serious medical problems. Dolly, for example, developed premature arthritis and lived only half a normal life span. Even carrying such a pregnancy to term may pose special dangers to the mother, due to the risk of "large offspring syndrome" and other problems. In short, anyone who chooses to reproduce this way must disregard the life and health of child and mother, to fixate on the supposed benefits of creating a much younger "replica" of oneself. Human reproductive cloning is a dangerous and unethical experiment on women and children.

Many scientists oppose "reproductive" cloning for these reasons, but still favor cloning for research. Yet the main difference between the two is this: In reproductive cloning, most cloned humans will die very young; in cloning for research, all of them will die, because they will be deliberately killed as means to someone else's idea of medical progress. The fact that this killing may take place at a very early stage makes no difference, for our moral tradition regards human life at every stage as deserving respect and protection.

Cloning for research presents a new evil not found even in the practice of abortion: creating new human lives solely in order to destroy them. This is the ultimate reduction of human life to an object, to a commodity that has no value except for the use someone else chooses for it. Pope John Paul II has underscored the grave evil of such experiments, calling them "atrocities" that are "unworthy of man" (World Day of Peace Message, January 1, 2001, no. 19).

Some try to obscure the gravity of such evils, by denying the humanity of their victim. They say the entity produced by cloning is not really a human being with a human soul. Sometimes they even claim that no embryo can be a human being until after implantation in a mother's womb. But these are self-serving arguments with no factual basis.

A human life begins when a new organism of the human species forms — that is, when the human genetic makeup is complete and the development of a new individual has begun. Implantation in the mother's womb is an important step needed for later survival — but it is essentially a change in location, one stage among many in a new life already begun. And while union of egg and sperm are the normal and usual way for such human development to begin, we now know there are other ways.

Catholics have no reason to deny that a cloned human has a human soul. Respect for natural reason, and for the equal dignity of all human beings under God, leads us to respect every member of the human species regardless of his or her origins. The account of Jesus' origin in the Gospel of Luke certainly reminds us that there may be more than one way to come into existence as a member of the human family!

But if cloning would create a fully human being, can it be wrong in principle? If the right to life were not under attack, and the death rate from cloning were greatly reduced, would Catholics still reject it? Answering this question requires an even closer look.

Cloning and Human Dignity

As the Second Vatican Council affirms, moral judgments about procreation must be based on "the nature of the human person and his acts" (Gaudium et spes, no. 51). To understand the nature of the act of human procreation is to realize why cloning does not respect this nature.

In sexual procreation, a man and woman join in a loving embrace that expresses their love for each other, and is open to cooperating with God to create a new person the two will love and care for together. This openness to new life sets the stage for our lifelong attitude toward our children. We know that our children arise from our act of self-giving love; that their makeup will be a new and unpredictable combination of traits from both parents; that we provided the opportunity for God's creative act, rather than forcing the production of a particular child. By the very nature of our procreative act, we respect God's creative role. We also show respect for our children, welcoming them as free and equal members of the human family with their own open future — as persons over whom we have stewardship, not absolute dominion.

Some reproductive technologies assist this natural process. But some ignore or violate its central features. These technologies make children result from the meeting of sperm and egg in a Petri dish, rather than from parents' act of embodied love. They introduce third parties into the procreative act, and allow technicians to manipulate and control life at its very beginning.

Human cloning is the final step down this path of depersonalized procreation. It involves no meeting of male and female at all — in fact, a child produced this way has no "mother" or "father" in the ordinary sense, but only a template or model. Instead of openness to life, it involves domination over life — for a technician manufactures the new embryo in a laboratory, and even controls his or her genetic makeup to be identical to that of someone else. This act has the nature of a manufacturing process, suited to a commodity rather than a human being. It dehumanizes in the act of creating.

This is not only a Christian insight, for it is imbedded in our human nature. Says ethicist Leon Kass: "Human cloning would ... represent a giant step toward turning begetting into making, procreation into manufacture (literally, something "handmade") ... [W]e here would be taking a major step into making man himself simply another one of the man-made things."1

Yet Christians above all should realize how important this insight is. Our Creed underscores the equality of God the Son with God the Father by insisting that He was "begotten, not made." The Son is not a creature like others, but arises in an eternally spontaneous outpouring of the Father's love. Our humility before God begins with the fact that although we are made in God's image and likeness, we are indeed creatures he has made, "the work of His hands." This is central to the infinitely vast difference between the divine and the human — a difference bridged only by God's free act of infinite love toward us.

When we manufacture offspring according to preset specifications, then, we are violating a fundamental aspect of human procreation. We are treating our children as inferior beings, as our "creatures." The other abuses of human cloning — the selfish fixation on producing a child "just like me"; the willingness to subject cloned humans to high risks of death and disability; even scientists' willingness to clone embryos solely to exploit and destroy them — flow from this first fundamental error.

Human cloning would create a human being who deserves to be treated as our equal, but would do so in a way that undermines this equal dignity. It is not a worthy way for humans to bring other humans into the world.

And there is still more.

Cloning and God

Cloning invites humans to treat their "creations" as less than themselves, as less than human. But it also tempts them to think of themselves as greater than human, as gods with the power to "create" life. This is, of course, the first and greatest temptation presented to human beings, to Adam and Eve: "You will be like gods" (Gn 3:5).

If this seems an exaggeration, we have only to look at statements by cloning proponents.

Dr. Lee Silver of Princeton University titles his book in favor of cloning Remaking Eden. In this Eden, the genetics expert plays the role of God, driving humanity to "self-evolve" into a superior race. He envisions a future in which "mental beings," "as different from humans as humans are from the primitive worms with tiny brains that first crawled along the earth's surface," find themselves "coming face to face with their creator" — and perhaps seeing "simply their own image in the mirror."2 The scientists who created Dolly the sheep call their recent book The Second Creation and they don't just mean creating sheep. "Cloning of the kind we have developed," they say, "makes it possible in principle to apply all the immense power of genetic engineering and genomics to animals .... and human beings, of course, are animals too."3

These scientists are not talking only about laudable efforts to use genetics to eliminate terrible disease. Cloning is a "gateway technology" to efforts to engineer the human species, for two reasons. First, genetic engineering is such a hit-and-miss procedure that one must be able to duplicate one's rare successes. Second, if scientists can make a new being who is exactly the same as another, they can refine their procedure to make that new being the same except for one or two "superior" traits, and then build on this. The human species itself would be the laboratory bench and the research animal for such experiments.

Tragically, many scientists are blind to the paradox in this grand scheme. When the true God makes people in His image and likeness, He produces an inexhaustible variety of people who reflect different facets of His infinite goodness. When we mere humans try to do the same, we only replicate one narrow set of traits already provided to us in the past ? and when we try to "improve" on that heritage, all we can apply are our own narrow, biased and imperfect ideas of a "better" human. By imposing those biases on our offspring, we would still treat them as objects we can control and dominate — even if we are trying to create a "superior" product. As C.S. Lewis prophesied over a half a century ago in The Abolition of Man, these new powers for controlling the species are not a net gain of power for humanity — they are ways for a few imperfect humans to exert control over many other humans and the future of humanity.

To imagine we are ready for such control over fellow humans is to commit the ultimate sin of overweaning pride — what the Greeks called hubris, the pride of grasping at what belongs only to gods. While any reasonable person can see the destructiveness of such pride, Christians know above all that the road to human progress is paved instead by humble service to others. Jesus' sacrifice blazed the right path for us long ago. From this perspective, human cloning and the mentality that accepts and uses it is an affront to God.


Catholics and others who respect human life stand at a crossroads. For decades we have waged a sometimes lonely fight to insist that innocent human life must never be attacked. Today we face a challenge that is more subtle, but even more overpowering, as human beings are tempted to exert ultimate control over the origins and traits of fellow humans. As ethicist Nigel Cameron has said, we are moving from the "Cain and Abel issues" to the "Tower of Babel issues," from denying human lives to denying our human limitations.

To be sure, the debate on "cloning for research" demonstrates that there will be much outright destruction of life along this path as well. But this willingness to destroy life is a symptom of a new level of disdain for human dignity, a mentality that treats other human beings as objects for our control. Nothing could be more alien to the attitude needed to build a culture of life.

Richard Doerflinger is deputy director of the USCCB Secretariat for Pro-Life Activities.