Review Essay of Robert P. George and Christopher Tollefsen, Embryo: A Defense of Human Life: Part I

William E. May
© 2009 Culture of Life Foundation.
Reproduced with Permission

This book is so important and rich in content that I will devote two reports to it. In Part I, I will summarize chapters 1 through 4; in Part II I will summarize chapter 5 through 8 and offer brief reflections.

Contents of Chapters 1-4

Chapter 1: What Is At Stake in the Embryo Experimentation Debate (1-26), emphasizes that a human embryo is a whole living member of the species Homo Sapiens in the earliest stages of his/her natural development that, unless severely damaged or denied or deprived of a suitable environment, will develop himself/herself to the next more mature stage of development, the fetal stage. The embryonic, fetal, child, and adolescent stages are stages in the development of a determinate and enduring reality - a human being - who comes into existence as a single-celled organism (the zygote), and develops, if all goes well, into adulthood many years later. The human embryo is a person worthy of full human respect, as subsequent chapters will show with philosophical arguments (3-4).

The issue in the embryonic stem cell controversy is "whether it is unjust to kill members of a certain class of human beings - those in the embryonic stage of development - to benefit others" (6). We can distinguish embryo science, embryo technology (ies), embryo ethics. Embryo science tells us what human embryos are and that in the vast majority of cases they begin at conception. Embryo technologies represent the ability of researchers to do things to or with embryos including destroying them. Neither embryo science nor embryo technology can give moral guidance on how to treat human embryos. That is the task of "embryo ethics." The book's thesis, rooted in principles of human embryonic ethics, is that "it is wrong and unjust to treat embryonic human beings as less than fully human" (7-22).

Outlining the balance of their book, the authors identify four ways to deny that embryonic human beings deserve full moral respect: (1) "one can deny that an early human embryo is a human being" - this view is discussed generally in chapter 2 while chapters 6 and 7 take up and rebut the claim that because early embryos can split into identical twins they are not yet individuals or determinate human beings; (2) "one can deny," as metaphysical dualists do, "that persons, the sorts of beings reading this book, are to be identified with biological entities that are human beings" -- Chapter 3 identifies the different forms of such dualism and shows them to be false; (3) "one can deny that all human beings deserve full moral respect." This view, called "moral dualism," asserts that respect is not owed human beings because of what they are. Like metaphysical dualism, moral dualism uses the language of personhood, but does so not to describe what humans are, but to describe a stage that most (but not all) human beings go through and that many pass out of before dying. Chapter five will show why this claim is false, making use of arguments rooted in claims about ethics defended in chapter four (23-24).

Finally, some argue that "we can both respect the embryos in the way they deserve, and use them in research involving their destruction. Crucial to this argument is the claim that the embryos in question - the "spare" embryos left over from their creation for reproductive purposes - are destined to be destroyed anyway. So nothing is lost, or there is no cooperation in wrongdoing, if rather than letting them go to waste, we make use of them for the greater good. The second half of chapter seven takes this up (25). Chapter eight formulates the authors' thesis and recapitulates the arguments defending it. The thesis states: "It is morally impermissible to engage in any research, for any purpose, that involves the destruction of human beings at any stage of their lives, including the embryonic stage, or in any condition, however weak or dependent…" (25).

Chapter 2: The Facts of Embryology (27-56), summarizes the facts established by embryology (embryo science), i.e., what it tells us about the human embryo and in particular about the origins of human beings as individuals like those human beings reading their book. It reviews the processes of gametogenesis and fertilization, describes what happens during the first, second, and third weeks after fertilization, and answers the question "What Is the Human Embryo?"

The section on human gametogenesis focuses on two significant facts. The authors think the first, while surely one of the most important events from the biological perspective, in an organism's life, less important from the perspective of their book's argument. This fact consists in the crucially important difference between the structure of somatic (body) cells and gametic (germ) cells. Somatic cells -- and every cell in every human organism is a somatic cell except that organism's gametic cells -- have a diploid structure, i.e., each somatic cell contains 46 chromosomes divided into 23 homologous sets of chromosomes, one set derived from that human organism's father, the other from his/her mother. Gametic cells, on the other hand, have a haploid structure, i.e., each has only half the number of chromosomes that somatic (body) cells have with their diploid structure, for a total of 23 paired chromosomes, with 22 pairs essentially identical in configuration and the 23rd strikingly different having X (male) and Y (female) chromosomes. Because of this crucially important difference it follows that in order to trace the biological developments ultimately resulting in a given human organism's coming into existence (e.g., Smith's) "we need to go all the way back to the beginning of his parents' lives. From the outset, these two young human organisms [his parents during their embryonic stage] are preparing for what, from the standpoint of biology, is surely one of the most important events of an organism's life - its reproduction. Each human embryo is not just busy with his own growth and development but is already laying the groundwork for the growth and development of his or her descendants" (32-34).

George and Tollefsen return to this fact later in commenting on the work of embryologists such as Keith L. Moore and T. V. N. Persaud, and they link it to the second crucial fact, the fact, namely, that sperm and egg are parts of the whole human organism and neither is identical with "Smith," who is a whole human organism nor with the human embryo that results from fertilization: "The newly formed zygote is genetically different from its parents. Of course sperm and egg cells were genetically different as well; but this genetic difference - their haploid rather than diploid nature - is itself a structural feature that reflects functional demands: the new human being (assuming no serious abnormality) must have forty-six chromosomes with genetic information from both parents, so the sex cells, whose job it is to unite to form the new human being, must have only half the total complement of chromosomes. This haploiditity of the gametic cells distinguishes them from whole human beings. The zygote, by contrast, is genetically complete. Its genetic difference is not a matter of genetic absence, as is a gametic cell's genetic difference from the other diploid cells of the organism of which it was a part. It has all the genetic information it will need to develop and grow into a much larger organism…the zygote itself does not serve a functional role in the biological economy of either parent; it is a separate organism, distinct and whole…[possessing] the active capacity for self-development toward maturity using the information it carries….In short, there are profound differences between the sperm and egg, on the one hand, and the newly formed zygote on the other" (40-42; see also pp. 27-36 for this "second fact").

Summarizing the process of fertilization (36-42), our authors highlight the facts of embryo science as formulated by embryologists such as Keith L. Moore and T.V.N. Persaud, who write in their The Developing Human: "Human development begins at fertilization when a male gamete or sperm (spermatozoa) unites with a female gamete or oocyte (ovum) to produce a single cell - a zygote. This highly specialized, totipotent cell1 marked the beginning of each of us as a unique individual. The zygote, just visible to the unaided eye as a tiny speck, contains chromosomes and genes (units of genetic information) that are derived from the mother and the father. The unicellular zygote divides many times and becomes progressively transformed into a multicellular human being through cell division, migration, growth and differentiation" (39-40).

Among the developments during the first three weeks of the embryo's life is the emergence during the third week of the primitive streak, a matter very relevant to the thesis of their book. Once it has begun, cell destination becomes much more definite. Prior to its emergence, cells are sufficiently uncommitted to specialized roles that when disrupted (biochemically or mechanically) monozygotic twinning is possible. The embryo can as a whole divide and each new embryonic whole is a new individual human being capable of developing into a mature adult. Does the phenomenon of twinning falsify their claim that the human embryo in its earliest stage as a unicellular zygote is a living human individual? In chapter 6 George and Tollefsen will show that monozygotic twinning in no way falsifies the claim that the embryo, prior to formation of the primitive streak, is a whole individual human being (42-48).

Chapter 2 ends by making 3 important points: (1) the embryo is from the start distinct from any cell of his/her mother or father; (2) it is human, having the genetic makeup characteristic of human beings; and (3) it is, most importantly, a complete or whole human organism, though immature, with the active capacity to continue development through further stages to maturity and beyond (49-56).

Chapter 3: Dualism and Persons (57-82), argues that the authors and readers of this book and all other beings who share their substance (nature, essence) are "living organisms of the human species, that is, human beings [and] such a position seems to be the height of common sense." It also argues that these beings are persons (59-60). Most philosophers are impressed by certain properties shared by the readers and authors of this book not shared with dogs or cats. The former possess reason or the ability to think critically, abstractly, logically, and the ability to choose and make decisions based on reason rather than follow blind instincts. They are also conscious, aware of themselves as selves, able to communicate. Some philosophers and others have concluded that these are essential properties of entities that can be called persons and that only entities possessing them are persons. Their position is dualistic. Our authors distinguish 5 forms of dualism, of which the first 4 are "ontological" or "metaphysical" dualism and claim that the "person" is one thing, while his/her "body" is another; the 5th, "moral dualism," is unlike metaphysical dualism in that it grants that the "person" and his/her "living body" are one unified entity but contends that certain properties must be present and in some way exercisable if the entity in question is to be considered worthy of full human respect. This chapter shows why metaphysical dualism is untenable; Chapter 5 will do the same with moral dualism, making use of arguments developed in Chapter 4.

Metaphysical dualism's forms are the following: (1) mind-body and soul-body dualism, (2) Lockean dualism, (3) brain-body dualism, and (4) constitutionalism. Plato and Descartes advocate (1), while Locke advocates (2). For Plato the person is the "soul," whereas the "body" is the prison of the soul; the soul exists prior to its union with the body and death is the liberation of the soul from the prison of the body. For Descartes there are two substances, extended substance or body and thinking substance or mind, with mind being the person. Both identify the true self or person with an immaterial entity substantially different from the body. Locke and those agreeing with him identify the person with "consciousness" or "self-consciousness." For them a person is a thinking, intelligent entity that can consider itself as itself etc. Moreover, and this is central, Lockean dualism holds that these properties must be actively possessed or be (more or less) immediately exercisable if there is to be a person, who is an entity separate from his/her body, coming to be only when an entity more or less capable of thinking and consciousness begins to exist and ceasing to exist when no longer capable of thinking and consciousness.

Philosophical materialists, judging souls and minds and consciousness too immaterial, today embrace (3), arguing that the mind is the brain; it is one substance and is identified with the person, whereas the rest of that entity's body is distinctly other than the brain. On this view persons do not come into being when the living body comes into existence but only when a brain develops; it holds that a different substantial biological but non-personal entity precedes the existence of the brain. The philosopher Lynn Rudder Baker is an advocate of (4), which holds that a human person is "constituted by" but "is" not identical to the living human body or a human animal. The animal under fitting circumstances "constitutes" the person, and in some instances may survive the person's destruction; were the animal destroyed before being constituted a person it would never have constituted one. A piece of cloth illustrates "constitutionalism." Its being a piece of cloth precedes its being a flag, and its being a flag requires fitting circumstances (e.g., the existence of a state), and obviously prior to its constituting a flag it was a piece of cloth and, had it been destroyed prior to being made a flag it would never have constituted one. Although view (4) differs from both soul-body and mind-body dualism insofar as there is no separate and independent entity that is the person, it is nonetheless a form of metaphysical dualism: the organic body, the animal, is not a person to begin with and often not during later stages of its existence as an animal. Baker herself thinks that the person "constituted" by this animal body might well be constituted by a different animal body or even by a nonorganic body such as a machine (62-68).

George and Lee on pp 69-81 present many arguments to show why metaphysical dualism is untenable. Several of them focus on the experience, common to all human beings (human animals), of engaging in activities that are simultaneously bodily and non-bodily in nature. It is one and the same being that sees (and perhaps also hears and smells and touches) a dog, for instance (a sensory, bodily activity or activities) and at the same time knows that the kind of being it sees etc. is a dog and can judge that the kind of being a dog is can bite whereas a worm (that it can also see and touch) is not the kind of being that can bite. The agent of all these activities is the one human animal, the one human being, not two different entities. They likewise point out that dualists typically make the capacity for psychological states (of consciousness, self-awareness, etc) the criterion for personhood - an entity is not a person if it does not have this capacity. But they fail to recognize that human beings in the embryonic stage or human beings who for some reason later in their lives are hindered from exercising these capacities radically possess these properties, but they need to be developed in order to be exercised. Each new human being comes into existence with the internal resources to develop such capacities and only the adverse effects of other causes will prevent their full development. Thus animalism or the view that human beings are essentially human animals, members of the species Homo Sapiens, is not only true but in harmony with the view that we are essentially persons not separated from our bodies but entities whose bodiliness is just as much integral to our being as is our capacity to engage in thinking, be consciously aware of ourselves etc. And we begin, as Chapter Two showed, at fertilization.

Chapter 4: Moral Philosophy and the Early Human Being (83-111), proceeds on the conviction that not all moral theories are equally sound - since many contradict one another, at least some must be false. It takes up the utilitarianism of Bentham, Mill, and Sidgwick and the consequentialism to which that utilitarianism led. Common to all utilitarian/consequentialist ethics is that no matter what its variety there will always be human beings who are dispensable, who must be sacrificed for the greater good. This ethic recognizes no inviolable human rights, such as a right to life or bodily integrity. Rights are correlative with duties. Thus innocent human beings ought not to be killed because others have a duty not to kill them. But for any consequentialist every moral norm is subject to an exception-making clause, e. g., "one ought not kill innocent human beings unless necessary to achieve a greater good." But how does one identify the "greater good"? Utilitarian/consequentialists fail to recognize that the goods at stake in choices are incommensurable. How can one compare the good of life itself with the good of exercising one's skills in work and play or the goodness of my life for me with the goodness of some other person's life for him? There is no common denominator to enable one to do so (91-94).

George and Tollefsen think that Kant's deontological ethics articulated a basic moral truth in affirming that human persons are never to be treated merely as means but always as ends, and because this is so, some moral norms are absolute and permit no exceptions whatsoever, no matter what allegedly "greater good" would be served were one to violate them and treat persons not as ends but as mere means. But they think that this moral principle, while true, is inadequate because its meaning is too vague and it fails to identify those aspects of the human person's being that we must respect. Moreover, Kant's emphasis is negative - what we ought not do - and does not help us in efforts to enhance human flourishing or well-being (95-97).

They thus propose a natural law theory that grounds the foundations of morality in the well-being and fulfillment of human persons and the communities they form.

Human nature, while quite determinate and distinct from other beings' nature, is complex. We are animals, but rational as well as sensory; we are individuals but social; we not only can know reality we can also transform it and change it. Our being has many dimensions or aspects, and multiple are the goods that perfect these dimensions or aspects and enable us to flourish and be more fully. Some of these goods are basic and are such not only because they fulfill different dimensions of our being but also because they give reasons for us to act in order to participate in those goods and do not need grounding for their intelligibility and appeal in some further reason. Unlike "instrumental goods" such as medicine or money, they can be rationally pursued for their own sake, and they are moreover, good for all humans so that we can act for these goods not only for our own sake but for the sake of others as well.

What are these goods? George and Tollefsen identify the following goods and the dimensions of our being fulfilled by them: with respect to our being as animals, there is the good of human life itself, including bodily health and integrity and the handing on of life; with reference to our being as rational, we find the good of knowledge of the truth; as beings who can transform the world through our own actions, there is the good of excellence in work or play; as social beings and members of communities, we find the goods of community, including friendship, marriage, and living in a just and peaceful society (all these are forms of harmony); and two further goods that are forms of harmony insofar as our wills need to be harmonized with the more-than-human source of meaning and value (the good of religion) and those aspects of one' self - the judgments of reason, emotions and disposition - that can conflict with one's choices (the good of all around "practical reasonableness" or "authenticity)." These goods are incommensurable; each of them and their instantiations provide an intelligible reason for acting and fulfills some aspect of our being. None is "greater" than any other; there is no "greatest good for the greatest number," nor is there any rational way of reducing them to some common denominator whereby they might be measured one against the other.

Natural law theory, so understood, proposes the following fundamental first principle of morality - the principle enabling us to distinguish between objects of choice that are morally good and those that are not: "in pursuing good and avoiding evil one must always will with a will open to integral human fulfillment," a general moral principle that can be specified or pinned down by more specific moral norms such as the Golden Rule or fairness and others. Other principles of this kind include the following: one ought actively pursue the goods and, where possible, cooperate with others in their pursuit; one ought not be satisfied by the appearance of knowledge rather than its reality or with "feeling" rather than "being" good. One further principle of this kind is that one ought not intentionally damage, destroy, or impede an instance of a real good's flourishing either within oneself or another either out of irrational hostility toward that good or because one prefers another good whose instantiation requires one's intentionally setting that good aside. This final moral norm specifying the basic normative principle definitively excludes the choice to destroy the good of human life in any human being. And this is a not a norm that applies only when an agent is motivated by hatred, anger, or hostility but also when he is motivated by the best of "intentions," for even though the end sought may be good, the means chosen (intentionally killing an innocent person) is evil (98-103).

George and Tollefsen apply this ethic to human rights and human dignity. Rights exist if there are principles of practical reason directing us to act or refrain from acting in certain ways out of respect for the well-being and dignity of the human being(s) whose legitimate interests may be affected by what one does. Some of these principles are affirmative - e.g., if a human good's flourishing in someone is endangered and one can reasonably do something to help remove the danger, one ought do so and the one whose good is threatened has a "right" to such help. However, coming to that person's aid here and now may conflict with other duties and other persons are better able here and now to help; if so, the principle does not apply. But negative principles always apply. Thus if one has identified an action type as being the kind of action requiring one to damage, destroy, or impede a basic good (e.g., life itself), then the principle applies and the right is absolute and inviolable. All innocent human beings have an absolute right not to be killed intentionally by others. Human dignity relates to basic goods and absolute rights as follows: First, human beings are fulfilled by the basic goods whereas non-human animals are not insofar as human beings are radically different in kind from animals who lack reason and will; second, others respect our dignity by respecting the flourishing of these goods within us and violate our dignity by willingly destroying, damaging, or impeding their instantiation in us. In the conclusion to the chapter our authors claim the following: 1. (most) human beings begin at fertilization; successful fertilization always produces a new human being; 2. The authors and readers of this book and all those essentially like them are human beings; 3. Human beings as such are subjects of rights, including the absolute right not to be intentionally killed; 4. Lethal research on human beings from their earliest stages (zygotic and embryonic) is morally wrong and violates human rights (105-111).


1 Nicanor Austriaco, O.P., shows that it is more accurate to call this "cell" an "organism" rather than a "cell." See his essay: "Static Eggs and Dynamic Embryos: A Systems Approach," National Catholic Bioethics Quarterly, Winter 2002, 666-667, cited at 41-42. [Back]