What moral status should we attribute to stem cells? To answer this neglected question, we look in this essay at the properties of embryos and other entities that could develop into beings who have uncontested moral status, namely, adult humans. Our analysis indicates that those who grant moral status to embryos should also grant it to stem cells. This has implications that verge on absurdity, since even if we were to try to do what we can to protect these entities, (...) we would face the dilemma that the development of any embryo requires the destruction of other potential beings. We respond to objections, including the claim that the destruction of human embryos is wrong not because of the potential of human embryos but because human embryos are actual beings with a rational nature. We conclude that the more plausible position is to deny moral status to embryos, and thus to stem cells as well. (shrink)

Scientific breakthroughs rarely yield the potential to engage a foundational ethical question. Recent studies on direct reprogramming of human skin cells reported by the Yamanaka lab in Japan and the Thomson lab in Wisconsin suggest that scientists may have crossed both a scientific and an ethical threshold. The fascinating science of direct nuclear reprogramming highlights empirical data that may clarify the ontological status of cellular activity in the early stages of what could become a human fetus and justify ethical options (...) for research in this controversial field. The ontological and ethical implications that accrue here are connected with the biological or natural potentiality of these cells. (shrink)

The paper by Magill and Neaves in this issue of the Journal attempts to rebut the "natural potency" position, based on recent advances in direct reprogramming of somatic cells to yield "induced pluripotent stem" (iPS) cells. As stated by the authors, the natural potency position holds that because "a human embryo directs its own integral organismic function from its beginning . . . there is a whole, albeit immature, and distinct human organism that is intrinsically valuable with the status of (...) inviolability and deserving full moral respect" (p. 26). The authors boldly assert that "The recent production of iPS . . . highlights a prima facie absurdity for the natural potentiality argument" (p. 29). Yet the argument against natural potency is both logically flawed and based on a characterization of the scientific evidence that is factually inaccurate. (shrink)

Debates on the moral status of human embryos have been highly and continuously controversial. For many, these controversies have turned into a fruitless scholastical endeavor. However, recent developments and insights in cellular biology have cast further doubt on one of the core points of dissent: the argument from potentiality. In this article we want to show in a nonscholastical way why this argument cannot possibly survive. Getting once more into the intricacies of status debates is a must in our eyes. (...) Not merely intellectual coherence but the standing and self-understanding of current stem cell research might profit from finally taking leave of the argument from potentiality. (shrink)