Human Cloning and Human Dignity:
An Ethical Inquiry

Table of Contents

The President's Council on Bioethics
Washington, D.C.
July 2002
www.bioethics.gov

Chapter Three

On Terminology

We begin our presentation of the important matter of terminology by listing the crucial terms used in this report:

• Human cloning.
  
• Cloning-to-produce-children.
  
• Cloning-for-biomedical-research.
  
• Cloned human embryo.

The rest of this chapter will develop the meaning of these terms and provide the analysis and argumentation that have led us to these choices. Because there is much to be learned about the subject through the discussion of alternative terminologies, and because we believe strongly that the judicious use of language is necessary for sound moral choice, we present our discussion of this matter at some length.

Introduction: The Importance of Careful Use of Names

Fruitful discussion of the ethical and policy issues raised by the prospects of human cloning – as with any other matter – can proceed only if we can find appropriate and agreed-upon terms for describing the processes and products involved. Before we can get to possible moral or policy arguments or disagreements, we need to agree about what to call that about which we are arguing. As a contribution to public understanding, we emphasize that this is not an easy thing to do, and we indicate how and why we have gone about making our terminological choices.

What exactly is meant by the term "cloning"? What criterion justifies naming an entity a "clone"? How is the term "cloning" related to what scientists call "somatic cell nuclear transfer (SCNT)" or "nuclear transplantation"? What should we call the single-cell entity that results from SCNT, and what should we call it once it starts to divide and develop? How, if at all, should our names for such activities or such entities be affected by the purposes we have for engaging in the activities or for using the entities?

As these questions imply, there is much confusion today about the terms used in discussing human cloning. There is honest disagreement about what names should be used, and there are also attempts to select and use terms in order to gain advantage for a particular moral or policy position. One difficulty is the difference between the perspective of science and the perspective of lived human experience. People who look at the phenomena of human reproduction and development through the lens of science will see and describe things in terms that often differ widely from those in ordinary usage; moreover, when an ordinary term is used in scientific parlance, it sometimes is given a different meaning. Similar divergences are possible also for people who look at these matters through the lens of different cultural, philosophical, or religious beliefs. Yet at the same time, all of us – scientists or not, believers or not – encounter these same matters on the plane of lived human experience, for which the terms of everyday speech may well be more suitable. Because this same common (nonscientific) discourse is also the medium of discourse for the ethical and policy discussions, we shall strive to stay close to common speech, while at the same time making the best use we can of scientific findings to avoid mistakes and misconceptions.

Advisers to decision makers should strive not only for accuracy, but also for fairness, especially because the choice of names can decisively affect the way questions are posed and, hence, how answers are given. The issue is not a matter of semantics; it is a matter of trying fairly to call things by names that correctly describe them, of trying to fit speech to fact as best one can. For the sake of clarity, we should at least stipulate clearly the meanings we intend by our use of terms. But we should also try to choose terms that most accurately convey the descriptive reality of the matter at hand. If this is well done, the moral arguments can then proceed on the merits, without distortion by linguistic sloppiness or chicanery.

Many of the terms that appear in the debate about cloning are confusing or are used in a confused manner.

First, there are difficulties concerning the terms that seek to name the activity or activities involved: cloning, asexual reproduction, reproductive cloning, nonreproductive cloning, research cloning, therapeutic cloning, somatic cell nuclear transfer (or nuclear transplantation), nuclear transfer for stem cell research, nuclear transplantation to produce stem cells, nuclear transfer for regenerative medicine. At stake are such questions as whether all acts of SCNT should be called cloning. Some worry that the term "cloning" unfairly prejudices people against the activity when it is used to describe research activities.

Second, there are difficulties concerning the terms that seek to name the entity or entities that result from human cloning (or human SCNT): cell, egg, activated cell, totipotent cell, clonote, reconstituted (or reconstructed) egg, zygote, clump of cells, embryo, human embryo, human organism, blastocyst, clonocyst, potential human being, human being, human clone, person. At stake here is the nature – and the possible moral status – of the entities that are involved in the subsequent manipulations, whether for producing a child or for use in biomedical research. Some worry that use of any term but "embryo" will unfairly prejudice people in favor of embryo-destructive activities by hiding from view the full import of the activity.

Third, there are difficulties concerning the terms that seek to describe the relation between the cloned entity and the person whose somatic cell nucleus was transferred to produce the cloned entity: genetic copy, replica, genetically virtually identical, noncontemporary twin, delayed genetic twin, clone.

Tools of Analysis

As a prelude to examining the activity or the deed of cloning, some general analytical observations will be helpful. Although all aspects of an activity or action are relevant to understanding its full human meaning, when describing a deed it is sometimes useful to distinguish what it is from both how it is done and why it is done. The act itself (what) may be accomplished by a variety of means or techniques (how), and it may be undertaken for a variety of motives or purposes (why). To be sure, there is a danger of distortion in this disaggregating analysis of human activity, and there is disagreement about the degree to which the motives or purposes of the agent are to be reckoned in the description of the act itself. People argue, for example, whether "mercy killing" differs as an act from murdering a rival (or executing a murderer or killing someone in self-defense), or whether they are all equally acts of homicide (literally, "killing a human being") whose moral meaning ("Is it justified or not?" "Is it wrong or not?") we can then proceed to debate, if we wish, by attending not only to the bare act of taking a human life but also to the agent's motive and purpose. Though we do not wish to beg this question, the very existence of this disagreement suggests that we do well not to ignore the naked act itself, for it may have a meaning independent of what moved the agent, a meaning relevant to subsequent moral assessment that we do not wish to overlook.

To illustrate: in vitro fertilization (IVF: the merging of egg and sperm outside the human body [in vitro = "in glass"], yielding a zygote that is the beginning stage of a new living being) is the deed (what). It is an act of "fertilization," of making fertile, of making the egg cell ready and able to develop into a human organism. This fertilization may be accomplished in at least two ways (how): by merely mixing egg and sperm, allowing the sperm to find and penetrate the egg, or by the technique of injecting individual sperm directly into the egg (a technique known as intracytoplasmic sperm injection, ICSI). And it may be done for the (proximate) purpose (why) of initiating a pregnancy, in turn for the (ultimate) purpose of providing a child for an infertile couple; or it may be done for the (proximate) purpose of providing living human embryos for basic research on normal and abnormal embryological development, in turn for the (ultimate) purposes of understanding human development or of discovering cures for diseases and producing tissues for regenerative medicine. Though the technique used or the purposes served may differ, in one crucial respect the deed (IVF) remains the same and bears a common intrinsic meaning: a human zygote, the first stage of a new human being, is intentionally produced outside the body and exists in human hands and subject to human manipulation.

As it happens, this fact is more or less accurately reflected in the descriptive terminology used for IVF. Interestingly enough, unlike the situation with cloning, no one distinguishes between "reproductive IVF" and "therapeutic IVF" or "research IVF," naming the activity or deed after the motive or purpose of the agent. This may reflect the historical fact that IVF was initiated by people who were interested in using it to produce live-born children for infertile couples; the research use of "surplus" embryos produced by IVF came only later. But it happens that this common name is also descriptively apt and remains so regardless of why IVF was done in a particular case: the deed is fertilization of egg by sperm, producing a living human zygote, the first stage of the development of a new human being.

It should be noted that, although we began by trying to describe the deed rather than the product of the deed, the two aspects merged necessarily. The meaning of the act of "fertilization" falls forward onto the nature of the "object" that fertilization produces: the fertilized egg or zygote or earliest embryo.i (By contrast, there is nothing in the name of the technique "intracytoplasmic sperm injection" that even hints at the immediate result or goal of the intended injection.) Similar attention to the nature of the product may turn out to be indispensable for a proper characterization of the activity of cloning.

Cloning: Toward an Appropriate Terminology

Though much of the terminological confusion and controversy concerns the way to describe the different kinds of cloning practices that are envisioned, the term "cloning" itself is not without its own ambiguities. A "clone" (noun, from the Greek klon, "twig") refers to a group of genetically identical molecules, cells, or organisms descended from a single common ancestor, as well as to any one of the one or more individual organisms that have descended asexually from a common ancestor. Both the group and each of its members are "a clone." "To clone" (verb) is to duplicate or produce a genetic duplicate or duplicates of a molecule, cell, or individual organism. The replication of DNA fragments in the laboratory is called "DNA cloning." The physical isolation of a single cell and its subsequent multiplication in tissue culture into a population of descendants is referred to as "single cell cloning." The laboratory culture of bacteria and the asexual propagation of plants by means of cuttings are instances of organismal cloning. Cloning of higher organisms is more complex: all cloning of vertebrate organisms must begin at the embryonic stages. Contrary to what some people imagine, cloning of amphibians or mammals (including human beings) is not the direct duplication ("photocopying") of an adult organism.

In the sense relevant here, "cloning" is a form of asexual reproduction (parthenogenesisii is another), the production of a new individual not by the chance union of egg and sperm but by some form of replication of the genetic makeup of a single existing or previously existing individual. (In biological or functional terms, the core of sexual reproduction is not bodily intercourse but the fusion of male and female germ cells; thus IVF, though it takes place outside the body, is – biologically speaking – a form of sexual reproduction.) Cloning is the activity of producing a clone, an individual or group of individuals genetically virtually identical to the precursor that is being "replicated."ⁱⁱⁱ

In much of the current public discussion, we encounter a distinction between two sorts of cloning: "reproductive" and "therapeutic." The distinction is based entirely on the differing goals of the cloners: in the first case, the goal is the production of a (cloned) child; in the second case, the development of treatments for diseases (suffered not by the clone, but by others). We recognize the distinction and the need for terms to describe the difference. But the terms currently in vogue have their difficulties. Both terms have been criticized by partisans of several sides of the debate, and for understandable reasons.

Some object to the term "reproductive cloning" used as a term of distinction, because they argue that all cloning is reproductive. Their reason: all human cloning intends and issues in the production of a cloned human embryo, a being distinct from the components used to generate it, a new human being in the earliest stage of development or "reproduction." (This claim, we would suggest, is at this stage a descriptive point, not yet a normative one; it does not necessarily imply that such a being is fully human or "one of us," hence deserving of the moral and social protection accorded "persons.") The fact that only some of these embryonic cloned humans are wanted for baby-producing purposes does not, in the view of these critics, alter this fact about their being. In support of their claim that cloning occurs (only) at the beginning, they note that once the cloning act of nuclear transfer has occurred, all new influences that act upon the new human organism cease to be "genetic" (nature) and are now "environmental" (nurture). Instead of "reproductive cloning," we shall speak of "cloning-to-produce-children."

Others object to the term "therapeutic cloning" for related reasons. The act of cloning embryos may be undertaken with healing motives. But it is not itself an act of healing or therapy.iv The beneficiaries of any such acts of cloning are, at the moment, hypothetical and in the future. And if medical treatments do eventually result, the embryonic clone from which the treatment was derived will not itself be the beneficiary of any therapy. On the contrary, this sort of cloning actually takes apart (or destroys) the embryonic being that results from the act of cloning.

To avoid the misleading implications of calling any cloning "therapeutic," we prefer the terms "research cloning" or "cloning for research," which also more accurately indicate the purpose of the activity. Yet some may find fault with this replacement. Because it appears to be a deliberate substitution for "therapeutic cloning," it may seem to imply that the scientists have abandoned the pursuit of medical cure in favor of research as an end in itself. Believing that producing cloned embryos just for research would seem to be less justifiable than producing them with healing motives, these critics of the term "research cloning" want to avoid giving the impression that scientists want to experiment on new life just to satisfy their curiosity. We believe that this legitimate concern can be addressed by appending the adjective "biomedical" to make clear that the aim of the research is to seek cures and treatments for human diseases. We therefore opt to use the term "cloning-for-biomedical-research."

Some proponents of the activity called "therapeutic cloning" also now object to the term, but not because of the adjective. Though it was proponents who originally coined and used the term, some of them now want to shed the term "cloning," fearing that the bad or distressing connotations of the latter will weigh against the activity itself. Cloning, they insist, should be reserved for the activity that produces live-born cloned babies; it should not apply to the initial act that starts the process, which they would rather call "somatic cell nuclear transfer" or "nuclear transplantation." 1 The reason for such redescription is not wholly cosmetic and rhetorical; because the researchers are primarily interested in obtaining pluripotent^v stem cells, their focus is on the somatic cell nucleus and what must be done to it (transfer or transplantation) in order for it to revert to the undifferentiated condition of the primordial stem cell stage. Nevertheless, such terminological substitution is problematic, for the following reasons.

Although as a scientific matter "somatic cell nuclear transfer" or "nuclear transplantation" may accurately describe the technique that is used to produce the embryonic clone, these terms fail to convey the nature of the deed itself, and they hide its human significance. The deed, fully described, is the production of a living human entity (or "embryo" or "organism"; of the right name for the product, more later) that is genetically virtually identical to the donor organism, a fact or meaning not captured in the name for the technique or method, the transfer of a somatic cell nucleus (into an unfertilized egg whose own nucleus has been removed or inactivated).vi As a name, SCNT is not a fully accurate description even of the technique itself. It makes no reference to the intended and direct result of the deed of nuclear transfer. It also omits mention of the fact that the recipient of the transferred nucleus is an (enucleated) egg cell (rather than another kind of cell), which then can be made to initiate cell division as if it were just like a zygote produced by fertilization. The further amendments, "somatic cell nuclear transfer for stem cell research" or "nuclear transplantation for regenerative medicine" or "nuclear transplantation to produce stem cells" only compound the difficulty, mixing in the purpose of the activity with its technique, thus further obscuring the immediate meaning of the act itself, the production of a living cloned human embryo.

Cloned Human Embryo: The Product of SCNT

What shall we call the product of SCNT? The technical description of the cloning method (that is, SCNT) omits all reference not only to cloning but also to the immediate product of the activity. This obscurity enables some to argue that the immediate product of SCNT is not an "embryo" but rather "an egg" or "an unfertilized egg" or "an activated cell," and that the subsequent stages of development should not be called embryos but "clumps of cells" or "activated cells." To be sure, there are genuine difficulties and perplexities regarding what names to use, for we are dealing with an entity new in our experience. Partly for this reason, some people recommend avoiding the effort to describe the nature of the product, preferring instead to allow the uses we human beings have for it to define its being, and hence its worth. But, for reasons of both truth and ethical conduct, we reject this approach as improper. We are all too familiar with instances in which some human beings have defined downward the status of other beings precisely to exploit them with impunity and with a clear conscience. Thus, despite the acknowledged difficulties in coming to know it accurately, we insist on making the effort to describe the product of SCNT as accurately and as fairly as we can.

The initial product of SCNT is a single cell, but it is no ordinary cell. It is also an "egg" and a "reconstituted egg." But even that is not the whole story. The "reconstituted" egg is more than reconstituted; it has been capacitated for development. Because the egg now has a diploid nucleus, it has become something beyond what it was before: it now contains in a single nucleus the full complement of genetic material necessary for producing a new organism. vii And being an egg cell, it uniquely offers the cytoplasmic environment that can support this development. The product of SCNT thus resembles and can be made to act like a fertilized egg, a cell that not only has the full complement of chromosomes but also is capable (in animals) or may be capable (in humans) of developing into a new organism. In other words, in terms of its future prospects, it is a "zygote-like entity" or a (cloned) "zygote equivalent." ^viii

The initial product of SCNT is, to be sure, not just a cell but an active cell. (More precisely, it is a cell that can be activated by electric stimulation.) But "activated cell" is much too vague to describe the activity of which it is capable. For, once stimulated, the activity of this "cell" produced by SCNT is nothing other than human embryological development, initiated and directed by the cell itself. The processes of cellular growth, chromosomal replication, cell division, and (ultimately) differentiation into the tissues and organs of the organism are coordinated processes under the governance of the immanent developmental plan encoded in the cell's genetic material. In other words, the product of SCNT is an organism in its germinal stage, and its activities are those of an integrated and self-developing whole.ix

Another suggested name, better than "activated cell," is "totipotent cell" – a cell that is "capable of all." But this too is ambiguous. If what is meant is that it can (and will, should it be stimulated to do so) become "any and all" of the different kinds of cells in the body, then it is an insufficient meaning. For, as explained in the previous paragraph, this totipotent cell may also become the "all" that is the integrated whole (cloned) mature organism itself (along with a portion of the placenta that would give it nourishment). In this second and fuller meaning of "totipotent," a totipotent cell is then just a functional synonym for the "zygote": "zygote" etymologically reminds one of the cell's origins in egg-joined-to-sperm; "totipotency" describes what it is capable of. A fertilized egg is precisely a "totipotent" cell; the product of human SCNT is, we assume, its equivalent.

In some discussions, the next few stages of the developing cloned human entity have been described as "clumps of cells." Yet, for reasons already given, this is only partially accurate. Viewed externally, under the microscope, the developing embryo will appear as two, then four, then eight cells "clumped" together, and the 100-to-200-cell blastocyst stage will indeed appear as a "ball of cells." Yet there is more here than meets the eye, for the "clump" is governed by an internal principle of development that shapes and directs its transformations. Thus, this ball or clump is not a mere heap or aggregate; it is a primordial and unfolding whole that functions as a whole and that is in the process of developing (or attempting to develop) into a mature whole being. Of course, if development is not pursued or not allowed to happen because of disruption, then the "clump of cells" description may be rendered accurate not just microscopically but also biologically. But as long as development continues and the developing entity is intact, that is not the case.

It would seem, then, that – whatever the reason for producing it – the initial product of somatic cell nuclear transfer is a living (one-celled) cloned human embryo. The immediate intention of transferring the nucleus is precisely to produce just such an entity: one that is alive (rather than nonliving), one that is human (rather than nonhuman or animal), and one that is an embryo, an entity capable of developing into an articulated organismic whole (rather than just a somatic cell capable only of replication into more of the same cell type). This is the intended primary product of performing SCNT, whether the ultimate motive or purpose is producing a live-born child from the cloned embryo or conducting scientific research on the cloned embryo. Also, the blastocyst stage that develops from this one-celled cloned embryo will be the same being, whether it is then transferred to a woman's uterus to begin a pregnancy or is used as a source of stem cells for research and possible therapy for others.

Yet, not surprisingly, objections have been raised to calling this cloned entity an "embryo," objections having to do both with its origins and with the uncertainty about the extent of its developmental potential. There are also objections having to do not with the facts but with public connotations and perceptions: for some members of the public, the word "embryos" apparently conjures images of miniature babies. If "nuclear transplantation to produce stem cells" seems to some people to be unfairly morally neutered terminology, "embryo" seems to other people to be unfairly morally loaded terminology, especially when used to describe an entity barely visible to the naked eye. We acknowledge this problem and recognize that, despite our best efforts, such difficulties in public perception probably cannot be simply corrected. But we do not regard this as sufficient reason to scrap the use of a term if it is in fact most appropriate. The other objections to calling the product of SCNT an "embryo" are not about rhetoric and politics, but about the thing itself. They should be addressed.

First, "human embryo," in the traditional scientific definition of this term, refers to the earliest stages of human development, from the zygote through roughly eight weeks of gestation, after which time it is called a fetus. Because the product of SCNT is technically not a zygote, not having come from egg and sperm, it is argued that it cannot therefore be an embryo. Second, it is said that it cannot be an embryo because it is an "artifact," something produced entirely by human artifice, "made" rather than "begotten." Third, we do not yet know for sure whether this entity can in fact develop into a baby; hence, we do not know whether it has the full developmental potential of a human embryo formed by fertilization.

There are, however, good responses to these objections. The first product of SCNT is, on good biological grounds, quite properly regarded as the equivalent of a zygote, and its subsequent stages as embryonic stages in development. True, it is not technically "zygotic" in origin, and it owes its existence to human artifice. But these objections, dealing only with origins, ignore the organization and powers of this entity, and the crucially important fact of its capacity to undergo future embryological development – just like a sexually produced embryo. True, it originates as a result of human artifice, and it lacks the natural bi-parental (male-plus-female) precursors. But this particular "artifact" is alive and self-developing, and should it eventually give rise to a baby, that child would in its being and its capacities be indistinguishable from any other human being – hardly an artifact – in the same way that Dolly is a sheep. True, regarding its developmental potential, we do not yet have incontrovertible proof that a cloned human embryo can in fact do what embryos are "supposed" to do and what animal cloned embryos have already done, namely, develop into all the later stages of the organism, up to its full maturity (à la Dolly). But if we do not assume this last possibility – an assumption based on the biological continuity of all mammalsx – there would be nothing to talk about in this whole matter of human cloning. As we emphasized in the first chapter of this report, this entire inquiry assumes that cloned human embryos can someday be developed into live-born human beings.

This decision, based on what we believe comes closest to the truth about the product of SCNT, is supported by other, more practical considerations. We are disinclined to introduce other words to describe the early product of human cloning that might deprive discussion of the ethics of human cloning of its humanly significant context. Despite the novelty of cloning and its products, their considerable kinship to elements of normal reproduction and development means that we enter upon the discussion equipped with existing and relevant terms and notions. We do not start in a terminological vacuum or with an empty dictionary. We observe that even people who prefer not to call the one-celled product of SCNT a zygote or embryo use terms like "blastocyst" and "embryo" to name the product a few cell divisions later.xi We think that using or coining other words will be more confusing to members of the public as they try to follow and contribute to the ethical discussion. And we clearly assume, as already stated, that the product of human SCNT could someday be shown to be capable of developing into a later-stage embryo, fetus, or live human being, even though such capacity has yet to be documented.

The product of "SCNT" is not only an embryo; it is also a clone, genetically virtually identical to the individual that was the source of the transferred nucleus, hence an embryonic clone of the donor. There is, to be sure, much discussion about how close the genetic relation is between donor and embryonic clone, and about the phenotypic similarity of the clone to the donor. xii Yet the goal in this process is in fact a blastocyst-stage cloned embryo (in the case of cloning-for-biomedical-research) or a child who is genetically virtually identical to the donor (in the case of cloning-to-produce-children); otherwise there would be no reason to produce a cloned embryo by SCNT rather than an (uncloned) embryo by ordinary IVF. A full and fitting name of the developing entity produced by human SCNT is "cloned human embryo," a term that also allows us to remember that, thanks to its peculiar origins, this embryo is not in all respects identical to an embryo produced by fertilization of egg by sperm.

As if things were not difficult enough, a further complication may soon arise, following reports of successful SCNT experiments in which human somatic cells were fused with animal oocytes, and the resulting product grown to the blastocyst stage of development. What are we to call the product of this kind of cloning? And what kind of species identity does it have? According to the advance reports (based on a presentation at a scientific meeting), the stem cells extracted from the blastocyst stage were demonstrated to be human stem cells (somewhat surprisingly, the mitochondria were also human in genotype). Is this, therefore, a cloned human embryo? The only test that could settle the question – implantation into a woman's uterus for attempted gestation to see if a human child results – cannot ethically even be contemplated without already assuming a positive answer. In the face of uncertainty, therefore, and lest we err by overconfidence, there is prima facie reason to include even these cross-species entities in the category of "cloned human embryos." (When we come to the ethical issues of cloning-for-biomedical-research, we can consider whether this terminological judgment is matched by an ethical one.)

Conclusion

None of the terms available to us is entirely trouble-free. Yet the foregoing analysis leads us to the following conclusion regarding the terms best descriptive of the facts of the matter:

Human cloning (what it is): The asexual production of a new human organism that is, at all stages of development, genetically virtually identical to a currently existing or previously existing human being.

Human cloning (how it is done): It would be accomplished by introducing the nuclear material of a human somatic cell (donor) into an oocyte (egg) whose own nucleus has been removed or inactivated, yielding a product that has a human genetic constitution virtually identical to the donor of the somatic cell. This procedure is known as "somatic cell nuclear transfer" (SCNT).

Human cloning (why it is done): This same activity may be undertaken for purposes of producing children or for purposes of scientific and medical investigation and use, a distinction represented in the popular discussion by the terms "reproductive cloning" and "therapeutic cloning." We have chosen instead to use the following designations:

Cloning-to-produce-children: Production of a cloned human embryo, formed for the (proximate) purpose of initiating a pregnancy, with the (ultimate) goal of producing a child who will be genetically virtually identical to a currently existing or previously existing individual.

Cloning-for-biomedical-research: Production of a cloned human embryo, formed for the (proximate) purpose of using it in research or for extracting its stem cells, with the (ultimate) goals of gaining scientific knowledge of normal and abnormal development and of developing cures for human diseases.

Cloned human embryo: (a) The immediate and developing product of the initial act of cloning, accomplished by SCNT. (b) A human embryo resulting from the somatic cell nuclear transfer process (as contrasted with a human embryo arising from the union of egg and sperm).

1. Vogelstein, B., et al., "Please don't call it cloning!" Science, 295: 1237, 2002. Back to Text
   
2. Leggett, K. and A. Regalado, "China Stem Cell Research Surges as Western Nations Ponder Ethics" Wall Street Journal, March 6, 2002, p. A1. Back to Text