“The development of a human being begins with fertilization, a process by which the spermatozoon from the male and the oocyte from the female unite to give rise to a new organism, the zygote.” — Langman’s Medical Embryology, 7th edition, 1995
For people who advocate the killing of embryonic human beings in the cause of biomedical research, the Holy Grail is an argument that would definitively establish that the human embryo, at least early in its development, is not a living human organism and therefore not a human being at all. The problem for these advocates is that all the scientific evidence points in precisely the opposite direction. Modern human embryology and developmental biology have shown that fertilization produces a new and distinct organism: a living individual of the human species in the embryonic stage of his or her development.
Some proponents of embryo-destructive research are willing to face up to these biological facts. They concede that human embryos are living individuals of the human species, but deny that this gives them the moral status of being persons. According to this argument, not all human beings are equal; not all possess inherent dignity and a right to life. Some, including those at early developmental stages, are not (or are not yet) “persons,” and they may therefore (at least in some circumstances, or in the pursuit of some goals) legitimately be killed.
There is much to be said against this position, but its defects are philosophical, not scientific. Its proponents recognize that there is no Holy Grail out there to find, and they are willing to defend the killing of human embryos while facing up to the biological facts. But then there are the Grail searchers. These people are determined to prove that what modern human embryology has been telling us is wrong, and to this end they scavenge the fields of molecular biology and human genetics.
Among the Grail searchers, there is none more determined than Ronald Bailey, science writer for the libertarian magazine Reason. Every now and then Bailey pops up to make a dramatic announcement: The Grail has been found! A few years ago, for example, he used a reductio ad absurdum that employed an analogy to cloning. Bailey offered to prove that every cell in the human body has as much potential for development as a human embryo. Therefore, he wrote, human embryos are the biological and moral equivalent of body (“somatic”) cells; they have no greater dignity than, for example, the skin cells that we rub or wash off our bodies every day.
Here is how the argument went: Each cell in the human body possesses the entire DNA code; each has become specialized (as muscle, skin, etc.) by having most of that code turned off. In the scientific process known as cloning, the portions of the code that were previously deactivated are reactivated. So, Bailey concluded, quoting bioethicist Julian Savulescu: “If all our cells could be persons, then we cannot appeal to the fact that an embryo could be a person to justify the special treatment we give it.” Since plainly we are not prepared to regard all our cells as human beings, we shouldn’t regard embryos as human beings.
Unfortunately for Bailey, his analogy between somatic cells and human embryos collapses under scrutiny. The somatic cell is something from which a new organism can be generated; it is not itself, however, a distinct organism. On its own, it remains just what it is (a constituent cell of muscle, skin, etc.). For it to contribute to the generation of a complete living being, significant interventions are needed, including the addition of critical molecular factors provided by a human egg cell.
A human embryo doesn’t need that. It already is a distinct, self-developing, complete (though immature) human organism. If someone tried to implant a somatic cell in the prepared uterus of a woman, nothing would happen — just as nothing would happen if someone tried to implant a sperm or an unfertilized egg. But a human embryo implanted in the prepared uterus of a woman will, barring some defect or accident, grow and develop, emerge from the womb some months later, soon begin walking and talking, and in a few years be asking mom and dad for the car keys.
So Bailey hadn’t discovered the Holy Grail after all. But now he’s back, claiming once again that it has been found. His claim comes in an online post criticizing an argument we made in response to some other Grail searchers.