April 10, 2002

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STEM CELLS AND LIFE



Dr Peter Carnley, Archbishop of Perth and Primate of Australia, explains why he believes John Howard's green light for stem cell research is a good first step towards resolving a difficult issue.


There was a time in the early 1980s when a story was in wide circulation about "when life begins". This question was said to have been put to a Roman Catholic priest, a Uniting Church minister and an Anglican priest.

The Roman Catholic priest said: "At the moment of fertilisation, when sperm and ovum meet, that is the point when life begins." The Uniting Church minister said: "No, it is at the point of quickening, when the mother first detects movement in her womb. That is when life begins." The Anglican priest said: "You've both got it wrong ... life begins when the last of the children leaves home and the dog dies!"

Clearly, trying to define when life begins is a little like trying to answer the question of when middle age begins. In one sense, human life does not begin at fertilisation since spermatozoa and oocytes are already alive in advance of fertilisation; they are living cells and spermatozoa display great activity. But the pressing question is: When exactly is the embryo to be accorded the status of an individual human person or potential human person for whom basic rights of care, protection, and, indeed, life may be claimed?

The theological principle behind medical ethics is that all human life is sacred, because we have all been created as unique human individuals by God with equal rights to protection and life. All Christians can agree about that.

What should by now be clear to everyone is that the question of when a human individual life may be said to have begun is a physiological question, not a theological question. It is a question that can only be answered by recourse to scientific information. It is not a question that can be rationally decided without appeal to evidence, for once we get into purely arbitrary statements of belief regardless of the available evidence, we are in danger of surrendering to rank superstition. A belief espoused contrary to the available evidence can never be rational.

Those in the western world who are persuaded that a human individual has been conceived from the "moment of conception" follow a teaching of Pope Pius IX which dates from 1869, when the destruction of a human life from that moment onwards was made punishable by excommunication.

However, at that early time, just what happened at "the moment of conception" was open to debate. The argument between Ovists, who believed that the mother contributed an ovum, and Animalculists, who, following Aristotle, believed that the male seed was simply implanted in the womb where it combined with menstrual blood to form the human embryo, had yet to be resolved.

This happened six years later when, in 1875, the Belgian Edouard van Beneden reported for the first time the process of formation of the mammalian embryo by the fertilisation of an ovum provided by a female with the sperm of a male. From that time onwards, it was natural for people to think of the "moment of conception" and the "fertilisation of an ovum" as being the same thing. Hence, the received assumption until recent times that the fertilisation of an ovum and the conception of an individual human person occur at the same moment.

We cannot, of course, level any blame at 19th-century people for not knowing what we now know today. The science of embryology has moved a long way. Since 1970, moral theologians have had their attention drawn to the fact that the fertilisation of an ovum, and the conception of a human individual, are in scientific terms identifiably different processes. The fertilisation of an ovum may happen in a moment of time, as the sperm "docks" with an ovum. But conception is now known to be not a moment but a process that takes 14 days. Only at the end of that process is it possible to say that "a human individual has been conceived".

During this 14-day process of great cellular fluidity, which ends with implantation and segmentation, twinning may occur. Alternatively, divided cells may recombine. It is only at the end of the 14-day process, once implantation has occurred and there is no further possibility of twinning, that we can logically say that a human individual has been conceived. In terms of simple logic it is not possible to make that assertion until the process of conception is complete.

In other words, at first the embryo in vivo is unattached, floating first in the fallopian tube and then in the uterine cavity. From the sixth to 12th or 13th day internal development proceeds within the blastocyst while, during the same period, implantation is taking place. Both internal and external processes of development are crucial to the future of the embryo. If implantation does not occur, the blastocyst is lost at or before the next menstrual period; if the inner cell mass does not form within the blastocyst, it does not have the potential to develop into a human individual.

Moreover, while fertilisation can happen in a laboratory, the conception of a human individual can only happen once the fertilised ovum is implanted in the womb of a potential mother. This is why we correctly speak of in vitro fertilisation, but not in vitro conception. IVF is a tried and tested procedure; IVC is an impossibility.

These physiological facts have been known by moral theologians at least since 1970. For example, they were clearly outlined by Professor Andre Hellegers of California, who was one of seven expert advisers of Pope Paul VI at the time of Humanae Vitae, in the journal Theological Studies. (Vol. 31, 1970, pp4-5). This was noted by the eminent Roman Catholic moral theologian Bernard Haring in a seminal book Medical Ethics (1972) when, in relation to the 14-day process of conception, he said: "... there has not yet emerged a human person ... individualisation seems not yet to have reached that point which is indispensable to personhood. In our philosophical tradition, it is a common presupposition that only a human life possessing irreversible individuality can be a person". (p80).

More recently, Fr Norman Ford, the director of the Caroline Chisholm Centre for Health Ethics in Melbourne, supports the same 14-day view in his important contribution to this discussion, When Did I Begin? (1988)

Professor Tony Coady has also published a very helpful piece in the January-February edition of the Jesuit publication Eureka Street.

In Anglican theological circles the new scientific information also began to be noted and taken seriously in the early 1970s. I myself first learnt the importance of distinguishing between the moment of fertilisation and the process of conception from Professor Gordon Dunstan (The Artifice of Ethics, 1973) who in the early 1970s taught moral theology and ethics at the University of London.

Before IVF became a topic of discussion, Dunstan used this distinction between fertilisation and conception in discussing the question of abortion after rape. He pointed out that immediately after rape, no human individual would have yet been conceived. There was therefore no question of talking of an abortion. Rather it was a matter of curettage.

Dunstan was the most eminent Anglican moral theologian working in the field of medical ethics at the time. He was very influential at the time of the Warnock Report of the British Committee of Inquiry into Human Fertilisation and Embryology and it is the theological and moral thinking underpinning the Warnock Report that today flows on into the most recent British legislation allowing stem cell research in the 14-day window between the fertilisation of an ovum and the completion of the process of conception.

Since 1869, theologians have tended to speak of the embryo resulting from fertilisation-conception as being endowed with a human soul by God at that moment. But this has not always been the case. St Augustine thought of "ensoulment" as a distinct additional act of God at around the 46th day after fertilisation. Aquinas thought that ensoulment happened 40 days after fertilisation in the case of males and twice that number of days after fertilisation in the case of females.

If we were to insist today that the embryo is endowed with a soul from the moment of fertilisation, we would then in the case of twinning be in the embarrassing position of having to say that one soul has become two souls. This should alert us to exercise caution in relation to soul talk. I understand that the late Professor Hellegers reported that all seven advisers to Pope Paul VI at the time of Humanae Vitae advised the Pope that "ensoulment" could not be located earlier than the 14th day after fertilisation.

Once we come to terms with the physiological facts and are in a position to distinguish between fertilisation of an ovum and the conception of a human individual, a number of troublesome difficulties fall away.

First of all, the natural wastage rate (which is said to be in the order of 60%) of fertilised ova because of failure to implant no longer throws up the problem posed by the apparent natural loss of very high numbers of "conceived human individuals". We quite simply are not talking of "conceived human beings" who never see the light of day.

Freezing of fertilised ova also seems more congenial once we are clear that we are not dealing with "newly conceived human individuals". We do not have some 70,000 frozen people on ice at various places around Australia.

It also follows that the growth of cells in the test tube is unlikely to be allowed after 14 days but, on the other hand, if there is a utilitarian argument for the possible benefit to mankind of experimentation on embryos, this can be tolerated in a controlled way under licence up to the 14th day in a way that after the 14th day it would not.

While it is not possible to assert that what is grown in the glass dish after fertilisation to eight- or 16 cell stage is rightly described as a "newly conceived human being", it is, of course, possible to speak adjectivally of human genetic material both before and after fertilisation, just as it is possible to speak adjectivally of human livers, human hearts, and so on. But it is entirely promiscuous to speak prior to the completion of the process of conception, of blastocysts as "newly conceived human beings", or "human subjects". Equally, research on blastocysts is improperly spoken of as "the destruction of human persons".

Stem cell research is therefore morally thinkable, for stem cells are harvested within the 14-day period before the completion of the process of conception. We may think of this in terms of a radical form of contraception, but not in terms of the killing of an already conceived human individual. Thus, Roman Catholics who are against contraception will naturally and consistently also be against stem-cell research. This position must be respected. Anglicans, however, since the 1958 Lambeth Conference, have not been living under that constraint, given the Lambeth bishops' endorsement of family planning, including the use of artificial means of contraception.

We all agree that human life is sacred. What we should also be agreed about is that the rightness or otherwise of embryo research is certainly not to be arbitrarily decided on the basis of the level of scientific knowledge as it stood in the middle of the 19th century.