Sense and Sentience
The Guardian, August 21, 1999
When a human embryo consists of not more than 64 cells, its cells are, like a young dog, able to learn new tricks. If injected into a diseased kidney, they take on many of the properties of ordinary kidney cells, and may help the kidney to perform its normal function. This seems to hold for any organ, even any kind of cell.
This is exciting medical researchers because it means that, at least in theory, the cells from an early embryo could eliminate the need for organ transplants entirely, cure leukaemia, enable people with diabetes to manufacture insulin, treat Parkinson's and Alzheimer's disease, and repair the nerve systems of quadriplegics. Though these prospects are still far from realisation, results achieved by Oliver Brustle at the University of Bonn Medical Centre have brought them a step closer. In an article published in Science on July 30, Brustle reported that he was able to repair the damaged nervous systems of rats using cells taken from embryos.
But medical researchers are not the only ones excited by the prospects of using embryo stem cells. In the US, 70 members of congress have opposed a proposal from the National Institute of Health, the major government funding body for medical research, to sponsor work using human stem cells. The National Conference of Catholic Bishops has lobbied congress to prevent the use of federal funding for the research, and when a coalition called Patients' Cure began to campaign for embryo stem cell research, Cardinal William Keeler of Baltimore wrote to the American Cancer Society, a sponsor of Patients' Cure, to urge it to reconsider its position. The American Cancer Society withdrew its support from Patients' Cure. In Britain, the government received expert advice that restrictions on research involving human embryos are hindering progress in the field, and should be loosened. In June the government rejected that advice. Opponents of research on human embryos usually start and finish their argument with the claim that the human embryo is, from the moment of conception, a living, innocent human being. But the morality of using a being for research should depend on what the being is like, not on the species to which it belongs.
Other things being equal, there is less reason for objecting to the use of an early human embryo, a being that has no brain, no consciousness and no preferences of any kind, than there is for objecting to research on rats, who are sentient beings capable of preferring not to be in situations that are painful or frightening to them. (Note the qualification `other things being equal". If the people from whom the egg and sperm were obtained would be distressed to know that an embryo conceived from these gametes was used in experimentation, that would be a reason why it might be wrong to do so. The same would be true if the experiments were badly designed, and so used scarce research funds for no good purpose.)
Some will protest that this is too swift. If being unconscious is sufficient reason for making it acceptable to carry out destructive experimentation on an embryo, why doesn't that apply to any one of us while we are asleep? And what about the potential of the embryo, which is entirely different from that of a rat?
The first question is easily answered. Although we are unconscious when we are asleep, we are conscious before we fall asleep, and our desires can reason ably be regarded as persisting, in a latent form, during sleep or other periods of temporary unconsciousness. We do not want to be killed while temporarily unconscious, so we can assume the same of others; but not of an embryo that has never been conscious.
The question of potential requires a fuller answer. A human embryo could, given the right conditions, develop into a self-aware, rational, autonomous human being, whereas a rat will always remain a rat, and we can assume - for the sake of the argument, anyway - that rats are not self-aware, rational and autonomous. Does this make any difference to how we should treat the embryo before it has realised its potential?
It could make a difference in various ways. For instance, since the embryo has the potential to become a person, it would be wrong to perform an experiment on it if, as a result of the experiment, the embryo develops into a person who suffers from an impairment. But this does not affect the ethics of experiments that result in the death of the embryo, rather than its impaired survival. The potential of the embryo should also make a difference if we have a good reason for wanting to bring into existence the entity that the embryo has the potential to become. If, for example, the embryo has developed from the gametes of a childless couple on an in vitro fertilisation programme, they will want the embryo to develop into a child, and it would be wrong to use the embryo in a non- therapeutic experiment.
Suppose, however, that the embryo is not wanted by the couple from whose gametes it developed. Let us assume that they have had other embryos fertilised, and as a result have had as many children as they wish to have. They are willing for this surplus embryo to be used for research. Should we, nevertheless, try to find couples who will carry this embryo to term, so that its potential can be realised? Why would we think that we ought to do that? Because we want there to be more people in the world? But if that is our goal, why are we so concerned about embryos, and not at all concerned about fertile couples who limit their families to one or two children when they could have half a dozen?
If such couples are under no obligation to bring as many children as possible into the world - if we don't even see that as a good thing for them to do - then why does the fact that the embryo has the potential to develop into a person mean that there is any obligation on us to refrain from destroying it? And if there is no obligation on us to refrain from destroying an embryo, then we should not stop researchers from destroying them, in the cause of medical research that holds out the promise of important benefits for our health.
Research on embryos should not be permitted if there is any possibility that the embryo is capable of suffering - but no one would argue that an embryo consisting of 64 cells could be capable of suffering. A developed brain and nervous system is a prerequisite for a capacity to suffer. It is sheer species-bias that makes us permit all kinds of trivial uses to be made of sentient non-humans and then prevent far more significant research from being carried out because it requires cells from early, non-sentient human embryos.