I was once a fetus A pro-abortion interlocutor having heard
these arguments may withdraw assent to the claim that I once was a fetus. She may turn what I said around and say that that fetus was not I, since I am essentially a person and the fetus (she will claim) is not. But this is untenable. For suppose, to obtain a contradiction, that the fetus was not I. Let “F” (rigidly) designate that being which the fetus was. Then, either F exists now or it does not exist. (Obviously, even if it exists now, it is no longer a fetus, just as that being that I was 20 years ago, though it still exists, is no longer a child.) Suppose F exists now.
Ex hypothesi, F is not I. So what is it? Well, given that F is an
organism (that is evident on scientific grounds), and that all the
organic parts of the fetus have developed into organic parts of me, it follows that if F exists now, F is a part of me. But,
ex hypothesi, it is not the whole of me, since I was not F and hence still am not F by transitivity of identity. So which part of me is it? Every part of my body has organically developed out of a part of that fetus. Therefore, I cannot separate out some proper part of my body now and say: "That part of me, that is F." Therefore, F now contains all of my body. Moreover, it does not contain anything outside of my body, since it is clear that in F''s developmental history nothing developed from organic parts of F that remained a living part and did not remain in me. So, F is an organism whose body is materially identical with my body; moreover, the parts of F are identical with my parts even
qua organic entities. But there surely cannot be two organisms that have the same body. Hence, if I am an organism, I am F. But it was assumed I am not F, and so I am not an organism. But this is dualism at its worst. For surely I am a rational animal, and to be an animal is to be a certain kind of organism. If Descartes were right, then of course one could hold that there is an organism, my body, which is distinct from my soul, and hence either the organism will be a proper part of me (if I am defined as an aggregate of body and soul) or will be something apart from me (if I am just the soul). However, Descartes is wrong. Surely it is evident that we
are animals, albeit rational ones, and that therefore we are organisms. (Note: A Thomistic or Aristotelian dualist account of the soul will not help the abortion supporter here. For to be an organism or animal is to have an animal soul, and so if I am not F, there are two souls in me: my soul and my body''s soul. But that is absurd and contrary to the subsumption of the lower parts of the soul.) So we see that we arrive at the absurd conclusion that we are not animals if we assume that F still exists but I was not F. Likewise, even someone who denies the fetus is a person is bound to feel the force of the claim that we are human beings and that the fetus is a human being, albeit at an earlier stage. Moreover, it is clear that if this is so, then the fetus is
the same human being as I am, since it develops into me continuously and naturally.