This is the full version of the article I wrote last month for the International New York Times on the debate about time limits for embryo research. (I cannot publish my INYT articles on Pandaemonium until a month after it is published in the newspaper.) It was originally published under the headline ‘Rethinking Embryo Research Rules’.
Few areas of scientific investigation are more controversial than embryo research. Yet, few are more brimming with potential. The field promises valuable insights into early human development and new possibilities for treating diseases and disorders.
For more than 35 years, there has been broad international agreement that no scientist can experiment on an embryo that is more than 14 days old. This red line was established as scientific guidance in the USA in 1979. It was incorporated into British law after the 1984 Warnock inquiry into in vitro fertilization. Other nations, including Australia, Sweden and China, have since adopted the same limit, either in law or through scientific regulation.
Until now, the 14-day limit has not been a particular issue because scientists, in practice, have been unable to grow embryos in vitro for more than nine days. But two research groups, one in America, the other in Britain, have recently reported being able to sustain human embryos in vitro for up to 13 days.
This technological advance has reopened the ethical debate about the 14-day limit. Many scientists chafe at restrictions on their ability to learn more about life and potentially create breakthrough therapies. Critics, especially religious believers, are horrified because they believe that, in the words of Philippa Taylor, head of public policy at the Christian Medical Fellowship, all embryos are ‘very young human beings’.
It is a controversy with important consequences not just for embryo research, but also for wider debates over abortion and infanticide. At the heart of all this lies a central question: ‘Where do we draw the line?’ Where is the line between a blob of cells and a human being? Or the line between matter that scientists can experiment upon, or a woman can choose to dispose, and an ‘individual’ with moral status?
The intractability of this issue reflects the fact that, as a matter of biology, the development of human life is rarely characterized by clear lines. A cell created by a fusion of egg and sperm is (if we ignore the possibility of cloning) a necessary condition of being a human being. It is not a sufficient one. A human being is created in the long journey from being a single, microscopic cell to becoming a self-conscious moral agent. That change does not happen at any one instant, but slowly over time, so that, almost imperceptibly, a qualitatively different being is created.
Some religious believers insist on a strong red line at the very beginning of this journey. A fertilized egg, they insist, is a human being and has moral status. Many object to any form of either abortion or embryo experimentation.
Others, such as the Australian philosopher Peter Singer, support both abortion and embryo research, but question whether a moral distinction exists between a fetus and an infant. Humans, according to Professor Singer’s critique of ‘speciesism’, have no intrinsic claim to life. The interests of individuals depend upon their cognitive abilities and on ‘characteristics like rationality, autonomy, and self-consciousness’. Infants, Professor Singer has argued, ‘lack these characteristics. Killing them, therefore, cannot be equated with killing normal human beings, or any other self-conscious beings.’ Killing an adult chimpanzee would be, for him, a more immoral act than killing a 1-year-old child, because the chimpanzee has greater cognitive capacities.
Neither stance seems to me plausible. The idea that a blob of cells is a human being and should have the same moral status as a child seems untenable. It is equally implausible, however, to claim that there is no moral difference between how an embryo and an infant may be treated.
While the creation of a human being is a process, not an instant, there are moral boundaries that mark qualitative shifts. One such boundary is birth. A fetus is a physical part of woman’s body. Abortion is not about the killing of another human being, but about a woman exercising her right to control her own body.
Birth transforms that relationship. An entirely physical attachment becomes primarily, and increasingly, social. A newborn child belongs to the moral community of humans. In that change lies the moral difference between a fetus and a newborn, and between abortion and infanticide. It is why abortion is permissible, but infanticide illegal.
Where does the debate about the time limit for embryo research fit into all this? The 14-day limit is arbitrary, but it reflects, in the words of the 1979 US report that first set the limit, the period ‘beyond the stage normally associated with the completion of implantation’. Before implantation, an embryo can divide into two, creating twins, or two different embryos can fuse together to create a single individual. So, many argue, implantation is the point at which the individuality of an embryo is assured — or when an individual soul is bestowed by God.
The notion that a cluster of cells that can no longer split should possess such special moral status is dubious. The anomaly of the limit to embryo research becomes evident when we compare it to abortion laws. In Britain, for instance, the normal limit for abortion is 24 weeks. It seems nonsensical for it to be legal to destroy a 24-week fetus in the name of a woman’s right to choose, but illegal for scientists to culture an embryo in vitro for more than 14 days for potentially lifesaving research.
The 14-day rule, as an opinion article in the journal Nature noted, was ‘never intended to be a bright line denoting the onset of moral status in human embryos’. Rather, it was ‘a public-policy tool designed to carve out a space for scientific inquiry and simultaneously show respect for the diverse views on human-embryo research.’ It was, in other words, a convenient fudge between the needs of science and the opposition, particularly of religious groups. With the advance of technology, that compromise is no longer workable, and so should be rethought.
Given that there are no sharp lines in the development of a human being, any time limit on embryo research will necessarily be arbitrary. The real point is not to provide spurious moral claims about whatever limit is set, but to win public support for whatever decision is taken. The line may be arbitrary, but the debate should be rational.
The images are of early human embryos, credit Rockefeller University.