In his essay "Why Abortion is Immoral," Don Marquis argues against the morality of abortion on the premise that the value of a fetus' future is so great that it is immoral to take that potential future away from it. Essentially, he contends, abortion is tantamount to murder: killing an individual is prima facie wrong because the loss of the goods of one's future is the worst loss a human can suffer. He calls this potential future a "future-like-ours," which is the basis for his contentions. In the next few pages I will delineate the general progression of his argument, and later, will evaluate the plausibility of said argument. Though Marquis makes both logical and compelling claims, there are several concerns and weaknesses that arise from his argument that must be considered.
Marquis establishes his argument with the exploration of why killing humans is wrong, in any case. The clear answer, he says, is that killing is wrong because of its "effect on the victim" (Ethical Issues in Modern Medicine, 558). Taking one's life deprives the victim of "all the experiences, activities, projects, and enjoyments that would otherwise have constituted one's future," and this is the greatest loss that any human can suffer (558). This theory of wrongness can account for why it is also wrong to kill infants and young children, whereas other theories that make narrower claims (e.g. "It is prima facie wrong to kill only rational agents) do not stand in such cases.
There are obvious implications concerning the ethics of abortion with this theory in place. Marquis contends that "The future of a standard fetus includes a set of experiences, projects, activities, and such which are identical with the futures of adult human beings..." (559). It follows then, that because it is wrong to kill humans, it is also wrong to kill potential humans, and so abortion is prima facie seriously wrong. Fetuses have a viable, valuable future, which Marquis calls a "future-like-ours." So, he adds, whether one has "immediate past experiences or not" does not matter when it comes to killing, because it is the value of the potential future that must be taken into consideration (561).
Marquis goes on to refute other theories of wrongness of killing. One such example is that valuing one's future implies a valuer, but fetuses obviously cannot value their futures, and so their futures are not valuable to them. However, Marquis counters this notion by providing us with an example: one may think during a time of despair that his "future is of no worth whatsoever," but he is wrong to think so because "others rightly see value...in it" (561). So, just because a fetus cannot appreciate its own future, we are aware of the value of its potential future, so abortion is still wrong. Other claims put forth that to be an actual victim, one requires mentation. However, we still recognize that it is wrong to kill those that are unconscious or in a coma (who have prospects of emerging out of their states), so it follows that mentation is not a necessary condition to be a victim. Marquis' refutations provide for his very strong and compelling argument against abortion.
I will grant Marquis that his progression of logic is rational; if a fetus were allowed to fully develop, it would indeed become a sentient being with the capacity of enjoying a prosperous future. However, some ambiguities arise as a result of his claims and it is difficult to say how Marquis would respond. The first concern I would like to address regards the case of a fetus with a debilitating disease. With today's technology, it is quite easy to detect any abnormalities in a fetus very early on in the pregnancy. Say, for example, a couple finds out that their fetus has some sort of affliction that will make him terminally ill. They want to abort the fetus because they cannot stand the notion of bringing a child into the world that, although sentient and...