Like sex cells, a somatic cell is functionally only a part of a larger organism. The human embryo, by contrast, possesses from the beginning the internal resources and active disposition to develop himself or herself to full maturity; all he or she needs is a suitable environment and nutrition. The direction of his or her growth is not extrinsically determined, but the embryo is internally directing his or her growth toward full maturity.
So, a human embryo (or fetus) is not something distinct from a human being; he or she is not an individual of any non‐human or intermediate species. Rather, an embryo (and fetus) is a human being at a certain (early) stage of development – the embryonic (or fetal) stage. In abortion, what is killed is a human being, a whole living member of the species homo sapiens, the same kind of entity as you or I, only at an earlier stage of development.
No‐Person Arguments: The Dualist Version
Defenders of abortion may adopt different strategies to respond to these points. Most will grant that human embryos or fetuses are human beings. However, they then distinguish “human being” from “person” and claim that embryonic human beings are not (yet) persons. They hold that while it is wrong to kill persons, it is not always wrong to kill human beings who are not persons.
Sometimes it is argued that human beings in the embryonic stage are not persons because embryonic human beings do not exercise higher mental capacities or functions. Certain defenders of abortion (and infanticide) have argued that in order to be a person, an entity must be self‐aware (Singer, 1993; Tooley, 1983; Warren, 1984). They then claim that, because human embryos and fetuses (and infants) have not yet developed self‐awareness, they are not persons.
These defenders of abortion raise the question: Where does one draw the line between those who are subjects of rights and those that are not? A long tradition says that the line should be drawn at persons. But what is a person, if not an entity that has self‐awareness, rationality, etc.?
This argument is based on a false premise. It implicitly identifies the human person with a consciousness which inhabits (or is somehow associated with) and uses a body; the truth, however, is that we human persons are particular kinds of physical organisms. The argument here under review grants that the human organism comes to be at conception, but claims nevertheless that you or I, the human person, comes to be only much later, say, when self‐awareness develops. But if this human organism came to be at one time, but I came to be at a later time, it follows that I am one thing and this human organism with which I am associated is another thing.
But this is false. We are not consciousnesses that possess or inhabit bodies. Rather, we are living bodily entities. We can see this by examining the kinds of action that we perform. If a living thing performs bodily actions, then it is a physical organism. Now, those who wish to deny that we are physical organisms think of themselves, what each of them refers to as “I” as the subject of self‐conscious acts of conceptual thought and willing (what many philosophers, ourselves included, would say are non‐physical acts). But one can show that this “I” is identical to the subject of physical, bodily actions, and so is a living, bodily being (an organism). Sensation is a bodily action. The act of seeing, for example, is an act that an animal performs with his eye‐balls and his optic nerve, just as the act of walking is an act that he performs with his legs. But it is clear in the case of human individuals that it must be the same entity, the same single subject of actions, that performs the act of sensing and that performs the act of understanding. When I know, for example, that “That is a tree,” it is by my understanding, or a self‐conscious intellectual act, that I apprehend what is meant by “tree,” apprehending what it is (at least in a general way). But the subject of that proposition, what I refer to by the word “That,” is apprehended by sensation or perception. Clearly, it must be the same thing – the same I – which apprehends the predicate and the subject of a unitary judgment.
So, it is the same substantial entity, the same agent, which understands and which senses or perceives. And so what all agree is referred to by the word “I” (namely, the subject of conscious, intellectual acts) is identical with the physical organism which is the subject of bodily actions such as sensing or perceiving. Hence the entity that I am, and the entity that you are – what you and I refer to by the personal pronouns “you” and “I” – is in each case a human, physical organism (but also with nonphysical capacities). Therefore, since you and I are essentially physical organisms, we came to be when these physical organisms came to be. But, as shown above, the human organism comes to be at conception.2 Thus you and I came to be at conception; we once were embryos, then fetuses, then infants, just as we were once toddlers, preadolescent children, adolescents, and young adults.
So, how should we use the word “person”? Are human embryos persons or not? People may stipulate different meanings for the word “person,” but we think it is clear that what we normally mean by the word “person” is that substantial entity that is referred to by personal pronouns – “I,” “you,” “she,” etc. It follows, we submit, that a person is a distinct subject with the natural capacity to reason and make free choices. That subject, in the case of human beings, is identical with the human organism, and therefore that subject comes to be when the human organism comes to be, even though it will take him or her months and even years to actualize the natural capacities to reason and make free choices, natural capacities which are already present (albeit in radical, i.e. root, form) from the beginning. So it makes no sense to say that the human organism came to be at one point but the person – you or I – came to be at some later point, To have destroyed the human organism that you are or I am even at an early stage of our lives would have been to have killed you or me.
No‐Person Arguments: The Evaluative Version
Let us now consider a different argument by which some defenders of abortion seek to deny that human beings in the embryonic and fetal stages are “persons” and, as such, ought not to be killed. Unlike the argument criticized in the previous section, this argument grants that the being who is you or I came to be at conception, but contends that you and I became valuable and bearers of rights only much later, when, for example, we developed the proximate, or immediately exercisable, capacity for self‐consciousness. Inasmuch as those who advance this argument concede that you and I once were human embryos, they do not identify the self or the person with a non‐physical phenomenon, such as consciousness. They claim, however, that being a person is an accidental attribute. It is an accidental attribute in the way that someone’s being a musician or basketball player is an accidental attribute. Just as you come to be at one time, but become a musician or basketball player only much later, so, they say, you and I came to be when the physical organisms we are came to be, but we became persons (beings with a certain type of special value and bearers of basic rights) only at some time later (Dworkin, 1993; Thomson, 1995). Those defenders of abortion whose view we discussed in the previous section disagree with the pro‐life position on an ontological issue, that is, on what kind of entity the human embryo or fetus is. Those who advance the argument now under review, by contrast, disagree with the pro‐life position on an evaluative question.
Judith Thomson argued for this position by comparing the right to life with the right to vote: “If children are allowed to develop normally they will have a right to vote; that does not show that they now have a right to vote” (1995). According to this position, it is true that we once were embryos and fetuses, but in the embryonic and fetal stages of our lives we were not yet valuable in the special way that would qualify us as having a right to life. We acquired that special kind of value and the right to life that comes with it at some point after we came into existence.
We can begin to see the error in this view by considering Thomson’s comparison of the right to life with the right to vote. Thomson fails to advert to the fact that some rights vary with respect to place, circumstances, maturity, ability, and other factors, while other rights do not. We recognize that one’s right to life