Answering a More Sophisticated Defense of Abortion - Part 7

A tactic often employed by us critics of abortion to defend life in the womb is to ask the defender of abortion if she would support killing a newborn infant. Her answer is usually "no." We then ask if she would end its life one minute before birth. The answer here is also usually "no." So we ask, "What about two minutes before birth or an hour before birth? Or a day before that? Or a month?" By this we attempt to show that, since there is a continuous line between the infant, which we wouldn’t kill outside the womb nor immediately before birth, the abortion defender has no reasonable place to draw a line as to when it becomes morally acceptable to kill the unborn. Another way of putting the argument is this: since there is no significant difference between the conceptus at each moment and the next, and since it will eventually develop into an adult that certainly has a right to life, one must conclude that the conceptus does as well. David Boonin calls this the "slippery slope argument" (pp. 33-45). I suppose he calls it that because if we say it is fine to kill the unborn at some point during the pregnancy what is there to stop us from killing at any moment after that? "It’s a slippery slope," the abortion critic would say. In any case, Boonin will attempt to show that the slippery slope argument is ultimately unsuccessful.

A common philosophical response to the slippery slope argument is to point out that the difference between the amount of light at noon and at one second after is not that significant. Nor is there any significant difference one second after that and one second after that, all the way to midnight, but this does not mean there is no significant difference between the amount of light at midnight vs. noon. Just because there is a continuous line from A to B, does not mean that A and B are the same. Similarly, just because there is a continuous line between the zygote and an adult, does not mean they are equally deserving of a right to life. However, even Boonin points out that this analogy is not good because degrees of light and the growth of a human are in very different categories. Whereas light comes in degrees, humanness does not.

Another response to the slippery slope argument that Boonin points out is to ask, "Why stop at conception?" That is, why not move backwards even further in time to include the sperm and the egg? Boonin does not find this move to be a good one either. If we are talking about my right to live at this moment and at every previous moment before that, there actually is good reason to stop at conception. I am not "I" until conception takes place. There is something fundamentally different between the sperm and the egg and what is conceived after fertilization.

So then, if Boonin thinks the two above arguments against the slippery slope argument are no good, how does he critique it? To begin, he brings up the idea of the "moment of conception." It is quite common for critics of abortion to use the expression "moment of conception," but Boonin points out that the expression is misleading. Fertilization of the egg by the sperm is actually a process that takes around 24 hours. Looking at the process in detail reveals that when the sperm penetrates the egg there is still a time (however short) where two distinct organisms exist, with one inside of the other. Boonin’s point is that even during the process of conception/fertilization there is not a decisive moment that is radically different from one moment before or one moment after. It is difficult (maybe even impossible) to point to such a moment in human development. To respond, we should actually agree with Boonin that conception is process not moment - embryology textbooks point this out. However, the process does have an end where we can say conclusively that the pronuclei of the sperm and egg have mingled and now only one organism exists - one that is a genetically distinct human being.

Boonin’s next move is tricky, so pay attention. Acknowledging (for the sake of argument) that we can point to conception as a definitive moment, he then points out that the purpose of the slippery slope argument is to show that a fetus has a right to life from conception because of the fact that it gradually develops into an adult that certainly has a right to life. In other words, it is the relationship of continuity with the adult that gives a fetus a right to life. However, Boonin subsequently argues that the real reason a critic of abortion wants to defend the fetus is not because of its relationship of continuity with the adult but because of what the fetus actually is and/or what the fetus has the potential to be. That is, Boonin wants to talk about the fact of continuity (what a fetus is developing into) as distinct from species membership (what the fetus is) and its potentiality (what the fetus may become). To me, continuity and potentiality don’t seem that different, but according to Boonin they are. In any case, Boonin asserts that critics of abortion don’t really rely on the slippery slope argument, but on arguments that stem from species membership and/or potentiality. Since he thinks he has already shown those arguments that rely on species membership to be unsuccessful and he will show those arguments that rely on potentiality to be unsuccessful (in the next section of his book), and since the use of the slippery slope argument is moot if no one really relies on it, then he has shown the slippery slope argument to unsuccessful by default.

While I realize that this post has gotten a tad lengthy and the last paragraph may not have made any sense, I will nonetheless give a response. I think the biggest mistake Boonin makes is his insistence on making separate the nature of the fetus, its continuity with the adult, and its potential to become an adult. (I’m still not sure about what the difference is between those last two). If he can distinguish between them, it seems that he can more easily show the arguments that rely on them to be unsuccessful. However, I would suggest the following: a fetus develops into (or has the potential to become) an adult because that is a function of its nature. It is therefore a mistake for Boonin to base his case on these distinctions, when it seems to me that, while these distinctions can be made in terms of philosophical categories, they cannot be separated in the actuality of human development. A fetus develops into a human adult and has the potential to be a human adult because it is a humanbeing. The nature of the fetus, its continuity with the adult, and its potential to become an adult come as a package.