This article appears in the May 2003 edition of the Catholic Medical Quarterly

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The Embryo Stem Cell Debate

Bernadette Tobin & Gerald Gleeson

Late last year the Australian Commonwealth Parliament passed legislation permitting destructive scientific experimentation on "surplus" human embryos. The Prime Minister portrayed the legislation as a "compromise" because it allows only existing surplus embryos to be used as a source of embryonic stem cells, and under reasonably strict conditions. The compromise will be short lived, however, because the Research Involving Human Embryos Act 2002 also allows subsequent governmental regulation to permit newly-surplus embryos to be likewise used in the years ahead: the prohibition on conducting research on embryos created after 5 April 2002 will automatically "sunset" in 2005. Indeed, Australia�s National Health and Medical Research Council has just released its new Draft Ethical guidelines on the use of reproductive technology in clinical practice and research: these guidelines assume that surplus embryos will be readily available for research purposes, once they are no longer needed in reproductive treatment programmes.

Advocates of destructive research on human embryos appeal to the supposed therapeutic gains that lie ahead. Privately, however, many scientists admit that the therapeutic use of human embryonic stem (ES) cells is not even on the horizon, not least because of its inherent dangers. ES cell research is currently focussed on cell function and cell differentiation. Because ES cells proliferate rapidly, they can be used to study the effects of drugs on embryonic development. Pharmaceutical companies, which find it difficult to trial new drugs on pregnant women, are very keen to conduct studies of the impact of their drugs on a developing embryo or foetus.

As is widely documented, all the many current therapeutic uses of stem cells involve a patient s own ("adult") stem cells, e.g. from bone marrow. The supposed goals and benefits of ES cell research (and the destruction of human embryos which this involves), by contrast, are clearly not what they are claimed to be. Nonetheless, it seems inevitable that destructive human embryo experimentation will become a regular practice in many of our research institutions. It is important, therefore, to continue to address some of the key claims often made in defence of this research.

Claim No 1: There is a fundamental distinction between "embryos for implantation" and "surplus IVF embryos"

This is a distinction without a difference. "Surplus embryos" from IVF programmes and "embryos for implantation" are just embryos. These different designations signal no more than the proposal to select some embryos for implantation, leaving others for experimentation. It is socially undesirable, and morally wrong, to promote the idea that there are two classes of human embryo: (1) those wanted by loving parents and (2) those who are a resource for science - and with no one to speak on their behalf. (Of course, given modern IVF techniques, there really should be no "surplus embryos", no embryos created other than for implementation.)

Claim No 2: So-called "surplus embryos" are destined for destruction anyway. Since they are going to be destroyed, it would be better to allow them to be used in research.

This claim is based on the false assumption that all that matters ethically is the "outcome" of a proposal. There is a very great difference between, on the one hand, dismembering an embryo for experimental purposes and, on the other, allowing an embryo to die unviolated. Of course it is true that in each case the embryo will die in the end. But just as there is a significant difference between the death of a person who is deliberately killed and the death of someone who dies from natural causes, so there is a significant difference between an embryo being deliberately dismembered and its dying naturally. The embryos to be experimented upon will most certainly die by dismemberment. Dismembering them, rather than allowing them to succumb unviolated, merely adds insult to the injury of their "surplus" creation and "unwanted"status.

In addition, it is arbitrary and unjust to select one embryo for implantation into a woman, thus giving it a chance to realise its developmental potential, and to select (or to abandon) another for death by dismemberment.

Claim No 3: Human embryos in themselves are not the kind of being deserving of a respect which would rule out using them in research: they are not "persons" (or "human beings" or "human persons" or "people", or whatever one chooses to call the kind of being which should never be treated merely as a means but always as an end in itself).

Answer to the question who, or what, constitutes a "person" depends on how one understands the concept of person. That concept is not a scientific or factual one. It is a philosophical one. The common understanding of person in our culture has been shaped by modern philosophy�s emphasis on consciousness as the mark of personhood. If only conscious beings can be persons, then - on this modern view - some people will question whether a severely demented or a brain-damaged patient is still "a person". A much older understanding of person, however, located personhood in the dignity of a being�s rational nature, irrespective of whether that being is conscious at a particular phase in his or her life. On this traditional view there is nothing problematic about saying that an unborn child or a persistently unconscious patient is a person, for they are truly our fellow human beings, sharing our rational human nature.

Because of the different ways in which the term "person" is understood in our culture, we would do better - in addressing the status of human embryos - to focus on what it is to be an individual human being. As Pope John Paul II notes in his encyclical The Gospel of Life, a human life begins at fertilization, with a life that is neither that of the father or the mother. So the onus of proof is on anyone who would claim a new human individual is not a human person.

The key to understanding what a human embryo is lies in the connection between a human embryo and an adult member of the human species. As Aristotle argued, the question of what something is can be interpreted in different ways. At the "material" level, an embryo is simply a group or collection of cells (or, is just one cell - at the point when fertilization is completed).

However, this answer does not tell us "formally" what an embryo is because it omits the most important truth about these cells (or about that first cell). These I or 2 or 4 ... cells are not simply cells that happen to be contiguous, to be sitting next to one another in a dish; these cells are a human embryo, they share in a single "act of living" which is that of a new human individual at the very earliest stage of its development. In short, a human embryo in itself is a single, integrated and developing organism with a life and identity of its own.

An embryo is not merely a living, cellular mass (although that is one answer to the question of what it is). More importantly, an embryo is an organised being that normally is in the process of maturing to the next stage of human development (that is the other, more crucial answer to the question of what an embryo is). It is true that there are embryos that are no longer able to mature as a member of the species (because of some inner defect). But the normal embryo does possess this potential and will, in an appropriate environment, realize it. That is to say, "potential" is not just an external way of speaking about the embryo (as "surplus" is); it marks an intrinsic quality of the embryo, its individual human nature, that which explains its characteristic development.

It is this intrinsic potential that explains why we should accord the embryo a kind of respect that is distinct from what we accord parts of the human body, or pieces of human tissue. It is this potential which makes irrelevant the facts that occasionally an embryo splits into two embryos and occasionally two such embryos recombine: in each of these circumstances there is an embryo (or more than one embryo) with the developmental potential to become an adult member of the human species. And it is the continuity of the embryo�s development of this potential that makes any linedrawing between one stage and the next quite arbitrary. Embryos are "potential children" in the same sense in which children are "potential adults" - not by the addition of any external factor, but simply by becoming more truly what they already are, human beings.

Claim No 4: We need to do both kinds of research: experimentation involving embryonic stem cells and experimentation involving "adult" stem cells.

Statements of "need" are often no more than statements of desire. It is true that some scientists desire to investigate embryonic stem cells, and it is certainly true that they have orchestrated a public campaign to support their cause. (Curiously most scientists have been content to allow the politicians whom they have "briefed" to make the overly-optimistic claims about imminent medical advances. Privately scientists admit that therapeutic interventions are a very long way off.)

When we say that we "need" to do something, we mean (at least) that the doing of that thing is required in order to achieve some purpose. However it is not obvious that experimentation on embryos is required for any therapeutic purpose: there are alternative sources of knowledge about human embryos (animal embryos) and alternative sources of knowledge about human stem cells (adult stem cells). Indeed if the purpose of work on embryonic stem cells is said to be the development of medical therapies, then it is clear that adult stem cells hold out more promise than do embryonic stem cells. Of course there is still much to be learnt before reliable and safe therapies using adult stem cells are developed; but none of this substantiates the claim that we "need" to work with embryonic stem cells.

Current therapeutic success involves adult stem cells; surplus embryos" will certainly not be used to develop therapies in the foreseeable future. Current experiments on embryos are rather for the sake of theoretical knowledge (eg in toxicology). At the most, therefore, destructive experimentation on human embryos might lead to some new knowledge about cell function being available a little more quickly than would be the case if only adult stem cells were used for research. However, given that there are no foreseeable therapeutic benefits directly obtainable from embryonic cells, there is no reason to think that prohibiting experimentation on human embryos will delay the development of therapies in any significant way.

Dr. Bernadette Tobin is Director of the Plunkett Centre for Ethics in Health Care.
Dr. Gerald Gleeson is Lecturer in Philosophy at the Plunkett Centre.

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