NATURE BIOTECHNOLOGY VOLUME 24 NUMBER 4 APRIL 2006 397 Can science resolve the ethical impasse in stem cell research? Evan Y Snyder, Lawrence M Hinman & Michael W Kalichman Advances in our understanding of the control of early human embryonic development could offer solutions to the moral dilemmas associated with human embryonic stem cell research. R elieving suffering and protecting human beings from harm are desirable and seem- ingly compatible goals. However, as has become clear, the derivation of stem cells from human blastocysts places these two goals on either side of a debate based primarily upon how one defines a human being 1–4 . At one extreme is the view that the moral status of human embry- onic stem (hES) cells is no different from that of any other collection of cells from the human body; it would be unethical to delay research with such cells while millions of people suffer from diseases for which we can offer little relief. At the other extreme is the view that, from the moment of conception, the embryo should have full moral standing as a person; it would be unethical to sacrifice the life of an individual for the benefit of others. Despite the apparent gulf between the diver- gent ethical positions of hES cell supporters and opponents, common ground can be found. For example, two convocations 5,6 of scientists and philosophers with diverse perspectives have been able to reach consensus on the following three points: first, the inner cell mass (ICM) of the human blastocyst (the source of hES cells) deserves consideration beyond that of a similar number of adult human cells; second, argumentation as to whether the preimplanta- tion zygote should, or should not, have moral standing equivalent to personhood is at an impasse (see Box 1); and third, without reso- lution of this impasse, a potentially powerful therapeutic approach may be left unexplored. To break this ethical stalemate, we must there- fore explore whether new avenues of research would allow the derivation of pluripotent cells without the need for blastocyst disaggregation or creation. Personhood The goal is to find a way to obtain pluripotent stem cells while still respecting the view that the fertilized egg is on a human trajectory. Is it pos- sible to alter the sperm, the egg or the process of fertilization in such a way as to produce cells that can meet the needs of researchers and clini- cians but that will not be on a path toward ‘per- sonhood’? Is this something that can be tested in the laboratory? In short, can science offer a way to avoid the moral dilemmas raised by this line of research? In past technology-driven controversies, data- derived insights have paved the way to common ground, showing that new insights from science could play a role in shifting perspectives. For example, we can cite the emergence of widely accepted brain-death criteria that permitted the Evan Y. Snyder is at The Stem Cell & Regeneration Program, The Burnham Institute for Medical Research, La Jolla, California 92037, USA; Lawrence M. Hinman is at The Values Institute, University of San Diego, 5998 Alcala Park, San Diego, California 92110, USA; and Michael W. Kalichman is at the Research Ethics Program, University of California, San Diego, La Jolla, California 92093-0612, USA. e-mail: esnyder@burnham.org; hinman@sandiego.edu; kalichman@ucsd.edu Ethical no-go. In 2001, US President George W. Bush and Pope John Paul II made clear that the destruction of embryos for the purpose of generating new ES cell lines violated their ethical principles. ©Reuters/CORBIS COMMENTARY © 2006 Nature Publishing Group http://www.nature.com/naturebiotechnology Nature Biotechnology, Vol. 24, No. 4 (April 2006), pp. 397-400.