I consider the argument, thought to clinch the moral case for use of a human embryo solely as a means, that only a human individual can be a person, because it can happen at any time before formation of the primitive streak that an embryo splits into monozygotic twins, no embryo in which the primitive streak has not formed is a human individual, and therefore no embryo in which the primitive streak has not formed is a person. I explore the (...) following proffered arguments for : indivisibility is a necessary condition of individuality, nonidentity of an embryo with successor twins impugns the embryo’s individuality, and totipotency of an embryo’s constituents is inconsistent with the embryo’s being a human individual. These arguments are tested and found wanting; so too is an alternative to , the argument that indivisibility is intrinsic to personhood. Whereupon is unsustained. In search of ways to rehabilitate the nonindividuation argument, I canvass alternative metaphysical views and inquire further into biological individuality, but find that the argument cannot be saved. I conclude by analyzing where this leaves matters concerning the morality of embryo use. (shrink)

I consider the argument, thought to clinch the moral case for use of a human embryo solely as a means, that only a human individual can be a person, because it can happen at any time before formation of the primitive streak that an embryo splits into monozygotic twins, no embryo in which the primitive streak has not formed is a human individual, and therefore no embryo in which the primitive streak has not formed is a person. I explore the (...) following proffered arguments for : indivisibility is a necessary condition of individuality, nonidentity of an embryo with successor twins impugns the embryo’s individuality, and totipotency of an embryo’s constituents is inconsistent with the embryo’s being a human individual. These arguments are tested and found wanting; so too is an alternative to, the argument that indivisibility is intrinsic to personhood. Whereupon is unsustained. In search of ways to rehabilitate the nonindividuation argument, I canvass alternative metaphysical views and inquire further into biological individuality, but find that the argument cannot be saved. I conclude by analyzing where this leaves matters concerning the morality of embryo use. (shrink)

It is becoming increasingly apparent that human embryo research has the very real potential to generate significant humanitarian benefits. Equally, it is clear that the destruction of embryos that such research inevitably involves is highly controversial within societies such as ours, where many hold either that from the moment of conception the embryo is morally considerable or that as a member of the human species it should not be treated as a mere means. How might we balance the potential humanitarian (...) benefits of embryo research against the various strongly felt moral objections to such use?In this rich and highly sophisticated work, Guenin argues for the experimental use of a bounded range of embryos, namely those which were intentionally produced for research ex utero and for which the progenitor has explicitly banned any intrauterine transfer. He argues that since they are not possible persons, it is morally permissible to perform experiments on this set of embryos.1 Indeed, he suggests that given the suffering that such research might relieve, it would be uncaring for us not to undertake it.As one might expect, the focus of the book is primarily on stem cell research. The ‘pluripotent’ stem cells one finds in …. (shrink)