Abstract

The author reviews one of the more intriguing articles in the stem cell research issue of the journal Metaphilosophy (April 2007), “Killing Embryos for Stem Cell Research,” by Jeff McMahan. He begins by recapitulating McMahan’s argument against the proposition that we are essentially individual human organisms. He then turns to two main critiques of the argument. First, he shows that the term “essentially” is insufficiently defined by McMahan and, more important, if we take the typical explication of the concept by modal metaphysicians, then the claim “we are essentially human beings” is true—contrary to McMahan’s argument. Second, the author offers a counterexample to McMahan’s implicit acceptance of the principle that only beings who have developed the capacity for self-consciousness are the proper subjects of moral worth. The author presents a regenerative therapy example to show that McMahan’s commitment on this point is counterintuitive. National Catholic Bioethics Quarterly 8.2 (Summer 2008): 255–264.