Michael R. Panicola, Three Views on the Preimplantation Embryo.

2 NAT'L CATH. BIOETHICS Q. 69 (2002).

The question of the moral status of the preimplantation embryo is one of the most controversial ethical and policy issues of the modern day. Previously held views on the value of human life in its earliest beginnings have been called into question, and collectively we have been charged with the responsibility of determining whether the preimplantation embryo is a full member of the moral community The strongest claims concerning the moral status of the preimplantation embryo have been made by the personal position, which maintains that personal life comes into existence at the completion of fertilization and is to be absolutely respected and protected in its inherent dignity This position has been challenged on two different fronts. First, the pre-personal position claims that the preimplantation embryo is in a pre-personal stage of development at least until it attains a certain level of biological stability, which coincides with the formation of the primitive streak, and as such is only entitled to limited respect and protection. Second, the nonpersonal position claims that the preimplantation embryo is a nonperson and as such is not entitled to any respect or protection. Both the prepersonal position and the nonpersonal position raise serious questions as to the plausibility of the view that a personal presence is discernible at the completion of fertilization. But neither position sufficiently refutes the personal position to the point that it would be justifiable to deny the preimplantation embryo the same degree of respect and protection given other human beings.

The pre-personal position's fundamental critique of the personal position is that as long as the cells of the preimplantation embryo remain in a totipotent state, the preimplantation embryo is susceptible to division through natural twinning or artificial separation in vitro and thus cannot be understood to be a single individual. One of the problems with this assessment is that it drastically overstates the nature of totipotency, and by association, twinning and individuality The totipotential capacity that resides within the cells of the preimplantation embryo is rarely actualized for the purposes of developing a separate organism. Identical twinning occurs naturally in approximately one out of 320 births. Since twinning is such a rare phenomenon, it does not provide an adequate basis for deciding the individuality of the...