Embryology, Philosophy, & Human Dignity
Ronald Bailey is still wrong.

By Patrick Lee & Robert P. George. Mr. Lee is associate professor of philosophy at the Franciscan University of Steubenville. Mr. George is the McCormick Professor of Jurisprudence at Princeton University.
August 9, 2001 10:35 a.m.

he science of human embryology stubbornly refuses to cooperate with Ronald Bailey.

Bailey continues to insist that embryos are analogous to somatic cells. It is, however, a stubborn fact of science that somatic cells are functionally parts of larger organisms. In this respect, they are analogous, albeit loosely, to gametes. Human embryos, by contrast, are distinct organisms that, unless prevented from doing so, actively develop themselves to more mature stages of the human organisms they already are with their distinctness and identity intact. That is why it is true to say that while you and I were never sperm cells or ova (just as someone who came into being by cloning was never a somatic cell), you and I truly were once embryos, just as we were once adolescents, children, infants, and fetuses.

When Bailey conceded in his original response to our criticisms that all of us were indeed once embryos, his claim to be able to show on the basis of science that human embryos are not human beings collapsed. So he quietly shifted the argument from science to philosophy. "When we were embryos," according to Bailey, "we were not yet people." Why not? Because, he claimed, only a being with mental functions, or the immediately exercisable capacity for such functions, has moral value (i.e., is a "person").

In response, we argued that human beings have intrinsic, and not merely instrumental, value. Each of us has worth because of what we are, not because of the properties or states that we happen to instantiate. (This is the basis of the principle of equal rights; no one has greater or less worth and dignity by virtue of differences in intelligence, strength, health, etc.) It follows that human beings have worth, dignity, and basic rights from the point at which they come to be. People do not acquire worth, dignity, and basic rights only after coming to be; nor can they lose these features prior to ceasing to be, by dying. All living human beings, irrespective of age, size, physical or mental ability, condition of dependency, or stage of development are owed respect; none may legitimately be enslaved or in any other way relegated to the status of a mere means to others' ends.

In his new reply, Bailey reiterates his claim that human embryos lack moral worth because they have not yet developed brains and the immediately exercisable capacity for mental functions. But he again fails to provide the slightest support for this position. In fact, he now makes matters worse by asserting that "if our brain activity ceases — our thoughts, memories, emotions, and intentions cease — we have ceased to be." If, as he had earlier agreed, human beings are essentially physical organisms, rather than (as philosophical dualists wrongly suppose) spirits or centers of consciousness inhabiting bodies, or, alternatively, mere series of experiences, then this claim is plainly false. In any event, Bailey's asserting it commits him to the very dualism he had previously — and rightly — rejected.

Bailey mischaracterizes and fails to come to terms with our refutation of his claim that possession of a functioning brain is a requirement of "personhood.". We did not argue merely that the brain-dead human being is dead while an embryo is alive. Our point was that brain death is accepted as the criterion of death not because the brain is needed for mental functions, but because without a brain at that stage of life then the organism ceases to be. After death, the cells in the corpse remain alive, but (if one assumes that brain death is a valid criterion) then there is not a unitary organism.

Moreover, as we and many others (including some who hold a position like Bailey's) have observed, there is no logically consistent way for someone holding Bailey's position to condemn the killing of infants or comatose humans, since these people also lack mental functioning. Bailey now replies that one can condemn killing the comatose, the asleep, and infants, because, "all have more or less functioning brains . . ." But the phrase, "more or less functioning," slurs over a crucial distinction. Infants and the permanently comatose do not have brains capable of sustaining mental acts. The function their brains perform is precisely to organize the various tissues and organs so that there is a unitary, self-integrating human organism — a function performed by other bodily parts in human beings at the embryonic stage. So, if one's reason for denying moral worth to human embryos is that they lack mental functioning, or the immediately exercisable capacity for mental functions, then it follows (as Peter Singer has the candor to acknowledge) that infants and people in permanent comas lack moral worth. But infants and the comatose clearly are beings of moral worth, and so Bailey's position is mistaken.

Returning now from philosophy to biology, Bailey takes one more stab at proving that human embryos are not human beings. We had asserted, in line with every scientific text on embryology we have been able to discover, that the embryo is a distinct member of the human species. Bailey now says that, "Science [our italics] shows us that it is not so." And how does science do this? "Since [identical twins] develop from the same fertilized egg, their genes are identical. They clearly become 'distinct' sometime after conception."

Bailey's claim that identical twin embryos are not distinct human beings because they lack distinct genomes, if correct, would prove that no identical twins (including, for example, 25-year-olds) are distinct from each other. It also would prove that all clones (of whatever species) are identical to the beings from which they were cloned. We clarified this issue in our second reply to Bailey: One set of evidence shows that the embryo is human; another set that the embryo is distinct from his or her mother and father (normally, though not in the case of clones, having a distinct genetic makeup); and still another set of evidence shows that the embryo is a whole organism, as opposed to being functionally a part of a larger organism.

What is true is that identical twins do not become distinct until the conception of the second one (so Bailey's claim that distinctness comes "after conception" is ambiguous — it is not clear which twin's conception he refers to). In every successful human conception, a distinct, living human individual comes to be with the fertilization of the oocyte by the spermatozoan. In the case of monozygotic twinning, another distinct, living human individual is generated from the cells of an already extant embryonic human being, through extrinsic division. (In recombination — what Bailey refers to as "chimeras" — one twin dies and his cells become part of the other twin.)

Twinning and cloning simply show that what is needed for the generation of a new individual is just this: a) the complete genetic code, either in the two sex cells in normal conception, or in the original cell from which a new offspring emerges (in twinning and cloning); b) factors derived from the maternal cytoplasm in the ovum (or oocyte in normal conception) that activate active development or growth; and c) a suitable environment. When these three factors combine, and not until then, a new and distinct organism is produced, its distinctness evidenced above all by the distinct direction of its growth, toward the mature stage of a distinct organism.

On a related matter, Bailey refuses to abandon his claim that the factors in ovular cytoplasm are mere environment. To our argument that the cytoplasm is in fact a co-principle because it enters into the constitution of the embryo, he replies that this also is true of nourishment. But he has again shifted ground. Nourishment is not environment. As the etymology of the word indicates, environment remains outside. The cytoplasm is not mere environment, since it remains within. But it also is not mere nourishment because nourishment merely sustains, while the fusion of the somatic cell with the enucleated ovum determines, a new direction for growth.

Bailey's recounting of scientific facts is marred by distorting interpretations. For example, he writes, "Once injected with egg cytoplasm [in cloning], the somatic cell is reprogrammed and begins the process of embryonic development." This description assumes that instead of the production of a new organism, there is only a stimulus or triggering. But the fundamentally new direction of growth is clear evidence against this. The precise difference between regular cell division (whether in mitosis or meiosis) and cloning is that in the latter case a new organism is generated. That difference in the case of human beings is certainly biologically significant. But it also is morally significant, unless one makes the philosophical error of identifying the human being with a mere consciousness or denies the intrinsic value of the substantial reality of human beings.

Bailey says that embryologists claim that, "as many as 50 to 80% of embryos created via normal conception naturally never implant," and then says that this somehow is evidence against our position. The argument is flawed: 1) Bailey is exaggerating the figure: 45% is the standard estimate (see Moore and Persaud, The Developing Human); 2) many of these are not normal successful conceptions — it is estimated that at least half are the results of incomplete fertilizations, and thus many apparently are not whole human beings; 3) the infant death rate a century ago was higher than this but no one suggested, nor would it be reasonable to suggest, that this was any evidence that infants lack humanity.

From his repeated assertions that, "Science shows" this, and "Science shows" that, one might infer that the scientists who have looked at this question have generally held that embryos are not human beings, and that it is we, not Bailey, who wish to reverse a generally accepted view. The exact opposite is the case. The standard embryology texts state clearly that in normal cases the beginning of a distinct human organism or human individual occurs with the fusion of the pronuclei of the sperm and the oocyte, producing the zygote. (See, for example, the embryology texts of: Moore and Persaud, O'Rahilly, Larsen, Carlsen, and Gilbert.)