There have been basic philosophical views presented regarding the rights of such potential persons. One group believes that the rights of the fetus, as a potential person, are negated in the face of the rights of the mother, who is already a complete person. On the other hand, there are those who believe that potential persons have as much right to life as existing persons. This opinion is based upon an ancient Christian theological position which equates potentiality with actuality (Harrison, 1983, p. 201). In contrast, there is the "process perspective" toward human life developed by the philosopher Alfred North Whitehead, which holds that potentiality can be affected by such factors as "selection, spontaneity, novelty, and at the human level of natural existence, rational freedom as constitutive of reality" (Harrison, 1983, p. 204). The first viewpoint is based on faith in the natural order as imposed by God, whereas the second viewpoint is based on the recognition that "human interactions intrinsically shape the natural life process and that actualization of potential in nature is always, to some degree, the result of valuation and choice" (Harrison, 1983, p. 204).
Arguments regarding the personhood of a fetus have also taken into consideration the degrees of development of the fetus. On the basis of this consideration, a variety of arguments have been advanced regarding the precise stage of development at which a fetus can first be