The embryo and the fetus: new moral contexts.

The ambiguous status of unborn human life contributes to the interminability of the debate about the morality of abortion. New medical research and therapies are implying questions about the value and protectability of life in its earliest stages, to which in vitro fertilization now gives more access. This essay will address especially the interplay of scientific information about embryonic development with philosophical interpretations of personhood. The ultimate question is whether full moral status in the human community ("personhood") can be tied to a physiological indicator or developmental line. Some ancient authors (Augustine, Aquinas) favored a theory of delayed ensoulment or "animation," on the premise that a human soul could be infused by God only when the body had reached an adequate level of development. The modern Church, drawing on improved scientific data about genetics, fertilization, and embryology, has tended to view human life as personal from "conception," on the assumption that at fertilization a new genetic code is created which establishes individuality and controls all further growth. Current controversy really has two centers. The first is essentially empirical and descriptive. It focuses on the question whether the best information available supports the view that individuality and the integrated function of the new organism are established at fertilization. The second is philosophical and normative. It raises questions about how to interpret the data: What aspects of human existence does the term "person" denote? What are the minimum criteria of being a person? What is the relevance to present moral standing of the potential to actualize personal characteristics? And are the Thomistic categories form and matter still useful in conceptualizing the relation of soul to body?