Ensoulment redux.

Cathleen Kaveny's column ("When Does Life Begin?" March 24) reveals the muddled state of prolife philosophy. The arguments of Germain Grisez and Paul Ramsey, as Kaveny describes them, both lead into fantastic realms, where biology and metaphysics try to mate in the hope of begetting ethics. This is nothing but the old debate about "ensoulment," unpromisingly reequipped with more precise biology and less precise metaphysics. Far more useful than such speculations would be wider acceptance of the rabbinic admonition to "make a fence around the Torah." Where grave sin (in this case, homicide) is possible, one must err on the side of caution. Better to treat a cellular structure that is not yet a person as if it were one, than to treat a human person as if it were not one. We do not know and, except by divine revelation, cannot know precisely at what point in its development a human zygote, embryo, or fetus becomes a human person before God. Because of this ignorance, we are morally constrained to treat a human organism as a human person at every stage of its development, beginning with fertilization. We are constrained, not by biological fact or metaphysical theory, but by the ethical imperative to avoid even the near occasion of grave sin. The philosophical muddle here may come less from new things we've learned about embryonic development than from old things we've forgotten about ethical behavior.

(REV.) DOHRMAN W. BYERS

Georgetown, Ohio