Madam, - Patsy McGarry provides an important suggestion when he writes that "if the death of the brain is the accepted terminus of human life, it should simply be logical to agree that detection of brain activity in the foetus could be accepted as the beginning of human life" (Rite and Reason, October 9th). Perhaps the beginning of personal human life might be a more accurate way to put it.
The fertilised ovum is human but there is a developing consensus that it is not personal in the sense used in Catholic moral theory which defines personhood in terms of an individual substance of a rational nature. For that definition to be verified the presence of the rational soul, or in ethicist Thomas Shannon's terms "immaterial individuality" is required. Shannon would locate that time as several weeks after the process of fertilisation begins (Theological Studies, December 1990; see also the National Catholic Reporter, June 2004 ).
That fertilisation is a process and not something that takes place in an instant was conceded by Pope Benedict XIV (1675-1758), who distinguished between active conception (the physical union of egg and sperm) and passive conception (the moment the rational soul is infused into a suitably organised body). And this distinction occurred in the context of Benedict X1V discussing the Immaculate Conception of Mary. By the time of Pius IX, ensoulment was regarded as coterminous with conception, which appeared to be instantaneous rather than a process. This is something few biologists would support today, when the stages of fertilisation of the ovum by the sperm are recognized.
Bernard Haering wrote in 1976 that the "argument that the morula cannot yet be a person or an individual, with all the rights of the members of the human species, seems to me to be convincing as long as we follow our traditional concept of personhood". The distinguished American moral theologian the late Richard Mc McCormick SJ wrote in 1990 that the pre-embryo not being a human person is "solidly probable".
Other theologians supporting the theory of the non-personhood of the pre-embryo are Donceel, Ford, Shannon, Wolter and Rahner. Some of these theologians base their conclusions on the high wastage that occurs in ova, up to 55 per cent of which miscarry soon after fertilization. While some of these ova (zygotes) may not have been fertilised for some reason and so may not be statistically relevant, the wastage of zygotes still appears to be high and counts against the probability of ensoulment. Are we to entertain the possibility that more than half of ensouled humans lived for a matter of hours only? To say yes and attribute this phenomenon to the "mystery of evil", as some moralists do, seems to be unacceptable.
In 1974 the Congregation for the Doctrine of the Faith acknowledged that the issue of ensoulment was still an open question because of lack of a constant tradition. The papal teaching office, then and since, urges that the benefit of the doubt must always be given to the life of the embryo even if the time of ensoulment is unsettled.
Pope John Paul II in Donum vitae (1994) wrote that "the conclusions of science regarding the human embryo provide a valuable indication for discerning by the use of reason a personal presence at the moment of this first appearance of a human life". Others read the scientific evidence differently, as we have seen, and so the dialogue between medical experts, philosophers, theologians, lay people and the papal teaching office should continue. Patsy McGarry has done a valuable service in opening up the issue again. - Yours, etc,
PAUL SURLIS, Crofton, Maryland, USA.