The supposed rights of the fetus. (Bioethics).

ISSUES ARISING from actual or proposed scientific research on human embryos have introduced a renewed urgency to the long-running public policy debate about the moral rights of human zygotes, embryos and fetuses. The debate inevitably provokes participants to make familiar claims about the ethical acceptability or otherwise of abortion, since the arguments about abortion and embryo research share some of the same logic.

Underlying issues relating to potentiality arise in all these arguments, though they can be brought out most clearly in a discussion of abortion, where there is a deliberate intention to end the development of a living organism that is clearly human (in the sense of its species membership). Furthermore, arguments based on the developmental potential of a zygote, embryo or fetus have been developed in their most sophisticated form in the context of the abortion debate.

I propose to revisit the implications of fetal potentiality--the potential for a fetus to become a fully developed human being--for the ethical permissibility of abortion. Except where specific distinctions need to be made, I will use the word fetus somewhat loosely, to refer to all stages of development from fertilisation to immediately before birth. I will argue that abortion does not violate any interest of the fetus that we are ethically obliged to respect. This does not rule out the possibility that some kinds of abortions are ethically impermissible for other reasons. For example, it might well be ethically impermissible for a woman to have a very late abortion, or to decide on an abortion purely because of the sex of the fetus. If so, however, the source of this impermissibility must be found elsewhere than in the mere fact that the fetus is a potential person or that it has some interest that is entailed by its potentiality.

If we reject arguments based on potentiality in the context of the abortion debate, it follows that we must also reject them in the context of debate over research on embryonic stem cells, or other research involving the destruction of human embryos. Indeed, there are broad implications for public policy in respect of contentious bioethical issues.

THE MOST SOPHISTICATED arguments that fetal potentiality does matter may be those developed by Jim Stone in two well-known articles published in the Canadian Journal of Philosophy, in 1987 and 1994 respectively: "Why Potentiality Matters" and "Why Potentiality Still Matters". In arguing that a fetus has serious interests that are harmed if it is aborted, Stone suggests that it has an interest in completing its normal developmental path in growing to become a human adult. To prevent this from happening is to inflict a serious and ethically impermissible harm on the fetus.

Stone suggests, with some reason, that "it is time we quit attacking straw men", that is, defending abortion by attacking unsophisticated concepts of potentiality. Clearly, it is desirable that anti-abortion arguments based on fetal potentiality be examined at their strongest, especially since such arguments have implications for other aspects of public policy in the field of bioethics. Accordingly, I have structured this article around Stone's argument and concepts. This provides a degree of focus and unity, while also ensuring that the concept of potentiality under discussion is one designed to avoid obvious absurdities.

Stone acknowledges that a fetus's mental and physical capacities are inferior not only to those of a human adult, but also to those of many adult non-human animals. It follows, in his view, that no obligation arises from any ethically significant physical or mental capacities that a fetus possesses. He suggests that any strong ethical claim to protection that can be made on behalf of a fetus must appeal to its potential to grow and develop into an adult human being, "for nothing else can justify it".