In "Thomson on Abortion" Baruch Brody poses an objection to Thomson's conclusion that a woman would always be morally permitted to terminate a fetus' life in self-defense. He argues that, in a case where the mother will be able to survive only if the fetus is aborted or the fetus will be able to survive but the mother will die, the person who is allowed to live and the one to die ought to be determined by fair and random chance rather than a decision just based upon the woman's wishes. He reasons that if chance determines that the woman should be allowed to live, abortion is morally permissible because one life would be lost regardless. Abortion would also be morally acceptable, he argues, in a similar case where both the woman and the fetus would die if nothing at all is done because one life could be saved instead of losing two. But, he says, it cannot be the case that abortions based purely on self-defense are justifiable because in a related case where two people are in a life raft and one contracts a survivable disease that would, however, kill the other person if he or she were to catch it, it is not morally permitted to kill the disease carrier. Brody's view is not as strict as the Extreme View that Thomson presented because there may be some conceivable cases in which abortion is permissible, but it does indicate that a woman is not morally justified in obtaining an abortion simply because her life is threatened.
I believe that Thomson would respond to Brody's objection by readily agreeing that in a
case where both lives could be lost that terminating one life so the other can survive is certainly better than losing two individuals. However, that is not to say that the determination of who is to live should be based on a flip of a coin. As such, no hung jury is allowed to resort to chance in a murder trial to determine the guilt or innocence of the defendant because doing so simply from a lack of an appropriate means to determine between the two verdicts undermines the pursuit of justice. Thomson would argue that the woman ought to have the right to deal out death to either herself or the fetus because she should have control over her own body. In other words, since the fetus makes use of the woman's body and not the other way around, the woman should be able to choose what happens to it even if it results in the termination of the fetus to preserve her own life.
I think that Brody would respond to this rebuttal by saying that the woman's ownership of her own body is not relevant in a case where either the woman or the fetus will die because the choice is between saving the life of the woman or that of the fetus and since there is a life at stake this trumps bodily rights. By Brody's view the woman's life is equally valuable to the fetus' life, a life for a life in other words, and each deserves a fair chance at being allowed to live. Thomson would fully give the decision to the woman, but this would fail to recognize the fetus' equal right to life, that Thomson recognizes when she bases her argument for the permissibility of abortion on a premise that acknowledges that the fetus is a human person.
To this, perhaps Thomson would say that although both the fetus and the woman may be persons with some right to life, those rights are not equal to one another as Brody states. The woman still ought to have the right to choose to terminate the fetus not only because her body is her own, but because of the comparable amount of suffering on her part is much greater than that of the fetus. Brody's recommendation seems to devalue any experiences and knowledge that the fully grown human woman has acquired to date and does not take into account the suffering that the woman can experience that the fetus is incapable of feeling. The woman, being a fully developed human, we know has thoughts and abstract desires for and about living her life while the fetus is unable to contemplate such thoughts. Therefore, by forcing a woman to roll the die or flip the coin, or even having someone else do it, she must deal with the suffering that would result by contemplating a death that she does not desire: her own. On the other hand, although the fetus may be a person, it is not a person that can suffer extra, as in the case of the woman, by being faced with its own death. Thus, the woman ought to be able to choose for herself whether or not to terminate the fetus in self defense to avoid the loss of her valuable experiences and thoughts and to avoid the extra suffering that will result by facing her own death.
Brody, Baruch. "Thomson on Abortion" in What's Wrong: Applied Ethicists and Their Critics, ed. David Boonin and Graham Oddie (New York: Oxford University Press, 2010), 99-101.