The question: Is the embryo already a person?
An examples of extrinsic criteria that has been positied is the 1960s idea that the status of the human being and the personality of an individual emerge at the moment of nidation, because this implicates the beginning of a close relationship with the mother.
Another extrinsic criterion is that the embryo becomes a human individual when recognized as such by positive law. "In our pluralistic society, the only possible solution to the controversy over the status of the human embryo is, according to many people, that such status be defined by democratic consensus. However the truth, even that regarding the status of the embryo, cannot be established by statistical survey.
A third criterion makes the status of the embryo depend on the choice of others to give the embryo created by 'in vitro' fertilization the possibility of further development by transplanting it to the uterus. In this case the the personhood of the embryo depends on the choices of others, such as researchers and parents.
The problem with this approach, according to 12th General Assembly of the Pontifical Academy for Life which held an international congress on "The Human Embryo," is that "this approach has not proved suitable for truly identifying the moral status of the embryo, since any possible judgment ends by being based on factors that are wholly conventional and arbitrary." Adriano Bompiani,gynecologist and director of the International Scientific Institute of Rome's Sacred Heart Catholic University, stated:
"In order to attribute a 'juridical status' to the embryo," said Adriano Bompiani, "it is necessary to 'understand' its nature." And such understanding, he added, must be based on ontological study.
"Today, it is not enough to examine the embryo under the microscope," he went on. Rather, it is necessary "to use all available means" from the fields of genetics, morphology, biochemistry and molecular biology.
In "recognizing" the embryo, Bompiani continued, "we come up against the concepts of human life, human being, human individual, and person. Reflection on these concepts is, obviously, the aim of ontological study. However, in my opinion, this should be undertaken only after having described and understood what happens in the few hours following the encounter between a living human ovum and a spermatozoon." From a rational standpoint, he concluded, the origin of a new human being lies "in the meeting between a spermatozoon and an ovum of the same species."
In the final communique of the International Congress, issued in March, the researchers and experts at the Congress stated:
It can be concluded from this data that the human embryo in the phase of pre-implantation is already: a) a being of the human species; b) an individual being; c) a being that possesses in itself the finality to develop as a human person together with the intrinsic capacity to achieve such development.
From all this may one conclude that the human embryo in the pre-implantation stage is really already a "person"? It is obvious that since this is a philosophical interpretation, the answer to this question cannot be of a "definite kind," but must remain open, in any case, to further considerations.
Yet, on the precise basis of the available biological data, we maintain that there is no significant reason to deny that the embryo is already a person in this phase.
Of course, this presupposes an interpretation of the concept of the person of a substantial type, referring, that is, to human nature itself as such, rich in potential that will be expressed during the embryo's development and also after birth. To support this position, it should be noted that the theory of immediate animation, applied to every human being who comes into existence, is shown to be fully consistent with his biological reality (in addition to being in "substantial" continuity with the thought of Tradition).
The Psalm states: "For you did form my inward parts, you did knit me together in my mother's womb. I praise you, for you are fearful and wonderful. Wonderful are your works! You know me right well" (Psalm 139:13-14), referring to God's direct intervention in the creation of every new human being's soul.
From the moral viewpoint, moreover, over and above any consideration of the human embryo's personality, the mere fact of being in the presence of a human being (and even the doubt of this would suffice) would demand full respect for the embryo's integrity and dignity: Any conduct that might in some way constitute a threat or an offense to its fundamental rights, and first and foremost the right to life, must be considered as seriously immoral.
Benedict XVI stated in his address at the beginning of the Congress:
“In man, in all men and women, whatever their stage or condition of life, there shines a reflection of God’s own reality,” the Holy Father emphasized. “For this reason, the Magisterium of the Church has constantly proclaimed the sacred and inviolable nature of each human life, from conception to natural end. This moral judgement also holds at the beginning of an embryo’s life, even before it is implanted in the mother’s womb.”