In this post, I will sketch the overall shape of Robert P. George and Christopher Tollefsen's argument.
Embryo begins with a biological argument that human embryos are distinct, whole human organisms. This is followed by a metaphysical argument that we adult humans are essentially (only) human organisms. Finally, a moral argument that human rights can only be held by adults by virtue of being human organisms...which applies equally to human embryos.
The Biological Argument
This section of the book hinges on the difference between organisms and mere parts of organisms. How can we count embryos as distinct organisms, while denying this status to eggs, sperm, and skin cells?
George and Tollefsen (G&T) don't provide a detailed general definition of "organism," but they do list features of embryos which set them apart.
...is a single biological system (p. 39)1
...is typically genetically distinct from its parents (p. 40)
...contains all the genetic information needed to develop into an adult human (p. 41)
...internally directs its own growth and development (p. 41)
...is actively developing toward maturity (p. 39)
Eggs and sperm each only contain part of the genetic information needed to develop into a mature human; nor are they actively developing themselves in that direction. Skin cells may contain full genetic information, but they aren't actively developing themselves in the direction of a mature human either.
Against arguments that embryos don't count as organisms on their own because they need to remain in a womb to survive, G&T write: "All human beings are dependent on their environment for their ability to grow, survive, and flourish, and human beings early in their development are no exception."2
The biological argument is successful when readers agree human embryos are whole human organisms at an early stage of development.
The Metaphysical Argument
This is the step that works better under a physicalist worldview because G&T argue against various forms of self-body dualism. In other words, they argue that you and I are identical to our bodies. We began to exist when our bodies began to exist; we will die when our bodies die. Since our bodies are essentially just human organisms, you and I are essentially just human organisms.
What is our substance kind, our nature, our essence? What sort of beings are we, substantially, rather than accidentally? We will argue in this chapter that we are, in fact, living organisms of the human species, that is, we are human beings.3What's the alternative? Plato and much of Christian tradition claimed that we are souls inhabiting a body, until our bodies die and our souls continue on. Descartes considered himself essentially a thinking being, and only accidentally an embodied being.4 Other forms of self–body dualism are mentioned, but you probably get the point by now.
G&T give three reasons to doubt dualism. First, they appeal to the way we naturally think of ourselves as walking, touching, eating, etc. Second, they bring up the problem of how "minds and bodies can have causal impacts upon one another" and suggest that skepticism about knowledge is only such a perennial nuisance because philosophers have accepted Descartes' dualist assumptions. Third, they accuse dualists of incoherence for attempting to explain one entity by introducing two entities, neither of which can be identified as the dualist.5
Still, some may object to G&T's animalist view that we are fundamentally human organisms (human animals), because our creative, intellectual, and moral abilities seem left out; these qualities seem objectionably omitted from what it means to be human persons.
The authors answer by pointing out that almost no one insists these abilities must be immediately exercisable in adult humans to count as a person (otherwise patients under general anesthesia would cease to be people for the duration). On the other hand, if capacity for characteristically human mental abilities is key, then human embryos possess such capacity in root form even as they develop themselves toward the point of exercising these abilities.
This metaphysical argument is successful when readers accept that they are identical to their bodies, when they agree they are persons by virtue of being human animals.
The Moral Argument
Once it has been established that both adult humans and embryos are essentially human organisms, it might seem the pro-life argument is complete. Not so fast. There are still pro-choicers who engage in what the authors call moral dualism, in which some human beings are accorded human rights but other human beings are not.
When it is a matter of race or ethnicity, color or gender, origin or outlook, our culture resolutely and rightly holds that what matters is the fact of humanity, and not any other property shared by some but not others. But, by the same token, in considering the status of embryonic humans, what should matter is the fact of their humanity. They should not be regarded as inferior to other members of the human family based on age, size, location, stage of development, or condition of dependency.6If we take human rights seriously as intrinsic moral dignities held by virtue of being human, then — considering the biological and metaphysical conclusions above — we cannot exclude human embryos. Moral dualists must undermine the concept of human rights, which would be a slippery slope to start down.
As you might have guessed, Utilitarianism and other consequentialist moral theories are rejected by George and Tollefsen. Such views don't take rights seriously as basic moral concepts. Is this an ad hoc move? No; plenty of other philosophers reject consequentialism for similar reasons without having the moral status of embryos in mind.
An Inconvenient Truth?
Embryo wraps up with a discussion of how public policy should change if the biological, metaphysical, and moral arguments are sound. The objection that pro-life policy is necessarily based on religious belief is defeated by this book's non-reliance on religion. And the objection that the treatment of embryos is a private matter can be answered by the appeal to human rights.
G&T call for the United States to continue the federal policy of not funding "embryo-destructive research" and for states to do the same. They also encourage increased funding for "research into adult, amniotic, and placental stem cells." Finally, they call for laws to ensure in vitro fertilization procedures only create embryos in the numbers that will be brought to term; adoption agencies should then push to rescue the current multitude of frozen embryos.7
I agree these would be appropriate public policy steps if the overall pro-life argument presented in this book were sound. However, I do have reservations, which I'll explain in a followup post (or posts, if needed).
1. These are semi-quotes.
2. George, R.P., Tollefsen, C. (2008). Embryo: A defense of human life. New York: Doubleday. p. 51.
3. ibid. p. 59.
4. ibid. p. 62-63.
5. ibid. p. 70-77.
6. ibid. p. 114.
7. ibid. p. 210-217.