In the ongoing debate over abortion and what constitutes life, neither the pro-choice nor the pro-life advocates have directly addressed the various criteria that may be applied to determining a definition of "life." Yet what constitutes a person or human can be examined on at least three dimensions of development: the biological, the social, and the psychological. If we use a psychological criterion or a social criterion, we may arrive at quite different points than if we use a biological criterion.
Yet it is the biological criterion that is almost always assumed, and little recognition is given to any alternatives. Anti-abortionists often recount the biological development of a fetus and present pictures or models of a fetus as proof of its personhood. But arguments involving biology are of value only to those who adopt that criterion. To those who do not, the arguments are irrelevant.
Yet even a biological criterion is not a simple one, for it involves a continuum of development rather than a single point. We could regard the single fertilized cell as comprising a person, or we could select the point at which the fetus has a tail and gill slits and looks much like any other species at a similar point of embryological development. We could select the point of development at which the fetus can be independently viable, that of not less than about six months of gestation, or we could select full-term development or beyond. The only social consensus we have on a criterion of biological development is that the beginning of personhood is not later than birth.
Social development is equally one of a continuum but has no development prior to birth. George Herbert Mead, the eminent sociologist, maintained that an infant is not born human. By that he meant that the socialization process begins only at birth and is gradually acquired through interaction with other humans. The Ashanti of West Africa name a newborn only after seven days, at which time he or she becomes a part of the social group. If the child dies earlier, that is of no great importance; for he or she was a nonperson. Similarly, the Todas in southern India regard an individual to be human only at three months. They give the child no name before that and death during the first three months of life is of no consequence. These groups have a consensus about social development as a criterion and act accordingly.
As to the psychological dimension, I suggest that the development of meanings of things is fundamental to becoming human. This can begin only at birth when the newborn for the first time begins to learn that colors exist, that objects have such properties as hardness, softness, coldness, and warmth, and that he or she can do things to objects or people and that they can do things to him or her. …