Embryo: A Defense of Human Life (Doubleday, 2008).,
Now four years old, George and Tollefsen's defense of embryonic human life in Embryo remains worthy of scrutiny because it represents a mode of public argument popular among Catholics today. That is to say, Embryo is a good test case for a particular version of "natural law" argumentation that attempts to shift public opinion toward traditional morality by appealing to the intelligibility of basic moral goods like the good of human life, without direct reference to metaphysics and theology. George and Tollefsen claim that their argument is founded on what philosopher John Rawls called "common human reason" (p. 143), rather than on any religious creed or dogma. Admirably, they place themselves on the front lines of the public bioethical debate, arguing in an accessible way against America's widespread approbation of embryo destruction.
Theircore premises, as enumerated in Chapter 1, represent a concise distillation of the basic pro-embryo argument: 1) The early human embryo is a human being; 2) All biological human beings are persons; 3) As persons, all human beings deserve full moral respect; and 4) One cannot respect and destroy a human embryo. The first premise is backed up by a thorough presentation of embryological science in Chapter 2, which confirms that the embryo is a unique human organism, having its own "active capacity for self-development" (p. 41). The rest of the book refutes those views that deny or undercut one or more of these core premises: Chapters 3 and 4 mount an attack on metaphysical dualism and utilitarianism - the broad philosophical positions underlying such denials - and chapters 5 through 7 confront particular arguments from contemporary bioethicists. On the surface, all of this appears to be a marvelously clear appeal to natural reason in defense of the embryo's right to life.
On closer inspection, however, one wonders whether their version of "natural law" argumentation naively ignores the fact that reason is always informed by culture. In light of America's current crisis over the status of human life in its early stages, the authors would agree that widespread consensus does not in itself make a view reasonable. Nevertheless, it seems that their attempt to communicate in the cultural idiom of our time leads to some significant philosophical errors.
Firstly, they accept the commonly held view that modern science, rather than natural philosophy, metaphysics, or theology tells us what a thing is. According to the Aristotelian natural philosophy appropriated by the Church, the nature or essence of a living thing - what it is - is determined by the kind of soul it has. Soul in this sense is an organism's transcendent life-principle, which guarantees its sustained identity as it develops in time. At several points, George and Tollefsen explicitly reject the concept of soul as part of the theological tradition.
Accepting modern science as the arbiter of facts thus leads to an inadequate understanding of the human organism as nothing but a system of developmental processes. Looking for the presence of new human life, George and Tollefsen rightly ask, "When is there a single biological system with a developmental trajectory, or active developmental program, toward the mature stage of a human being?" (p. 39). Self-organized development is indeed a manifestation of life, and modern biology is helpful in analyzing and elucidating the nature of this development. However, no organism is simply identical with the manifestation of its self-development. Soul is not merely a matter of religious revelation, but a philosophical principle intuited from the organism's capacity to remain a single living whole despite its ongoing transformation in appearance. More than just a mind or conscious self, the transcendent rational soul is also the underlying form of the human body. Without this principle, the human organism is reduced to its material or phenomenal parts and processes.
George and Tollefsen recognize that an organism is a unified, self-integrated system of development, not a mere heap of matter, and therefore their reductionism takes a rather subtle form. Their view is further complicated by their acceptance of a philosophical position known as "animalism," which makes the general claim that every human organism is a self or person. On their scientific terms, this self or person, which animalism identifies with the organism, becomes reducible to the system of processes discerned through biology. By conflating self, organism, and the visible system of biological development, they leave one wondering who or what "self" integrates the "self-integrated" embryonic system?
This is not just metaphysical quibbling, for it has significant ethical implications. To note one concrete example: George and Tollefsen hastily endorse the current medical criteria for brain death. They equate brain death with the death of the person, "because the irreversible collapse of the brain destroys the capacity for self-directed integral organic functioning of human beings who have matured to the stage at which the brain performs the key role in integrating the organism" (p. 133). However, if they had affirmed that the rational soul, rather than the brain, integrates the organism at all stages, they might have more qualms about harvesting organs from a still-breathing human being. And with regard to embryo ethics, one can see how their reduction of life to visibly organized development might lead them to mistake an apparently undeveloped or undeveloping human embryo for a non-human, and thus to unwittingly condone embryonic manipulation in such a case (specifically, I am thinking of George's official approval of the ANT-OAR technique in 2005).
A second assumption they share with the larger culture is that truths about nature as such play no role in determining our moral goods. They tacitly accept what philosophers call the "naturalistic fallacy": the view that one cannot argue from an "is" to an "ought." Accordingly, there is fundamental divide for them between science, which tells us what things are, and moral philosophy, which tells us what we humans ought to do (p. 8). Generally speaking, this view seems to devalue creation by implying that nature in itself, including the human body, has nothing to tell us about how to live well. More to the point, it makes a persuasive argument in defense of embryonic life impossible in principle, because goods like human life cannot be rationally defended based on the nature of reality as such, but can only be asserted as irrefutable first principles of moral reasoning. George and Tollefsen merely assert that human life at all stages is one of the "basic human goods" necessary for a fulfilling human life. But what if one disagrees about the status of embryonic life as a basic good, as presumably the proponents of embryo destruction do? They present no actual argument as to why these goods are fulfilling or basic; they are mere postulates of an otherwise unfounded "moral philosophy."
Embryo thus succeeds only in affirming the moral values of those who already agree with its authors. In order to convert their opponents, George and Tollefsen would need to root the basic goodness of dependent human life in a more inspiring metaphysical and theological vision of existence as a matter of love. Such a robust metaphysics and theology, however, are excluded from their decidedly modern sense of public reason. In effect, then, their "natural law" arguments do little more than reinforce the status quo, including those aforementioned assumptions about the role of science, the meaning of soul, and the divide between fact and moral good. Despite these problems - or perhaps because of them - Embryo can teach us a great deal about the current state of the contemporary bioethical debate.