More On Stem Cells

William Saletan continues his series, "The Organ Factory," in Slate. Yesterday, he examined the basis for setting 14 days as the cutoff point for harvesting stem cells from embryos. His argument is that the timeframe is arbitrary, not based on the actual development of the embryo, but rather arrived at backwards by determining when scientists thought was a good timeframe and then crafting an argument to show there are no ethical problems with that timeframe. Saletan's earlier entries showed that differentiated stem cells hold much more promise to treat illness, so a lengthier timeframe, in the seven-week range, would be more useful. So, can we do the same sort of backwards rationale to develop an ethics that allows harvesting at seven weeks?

That's exactly what Saletan does in today's piece. He examines each ethical criterion and shows how it can be extended to reach the pragmatic goal of allowing harvesting of differentiated stem cells. Of course, the argument starts reaching into weighty issues, such as, when does an embryo become a sentient human life?

It will be interesting to see exactly where Saletan takes the discussion. Adopt a cynical tone of voice, and you can imagine Saletan laying out a logical trap that leaves the reader bereft of morals in a world in which anything goes and the most precious life is the one that can pay to manufacture beings deemed less worthy of living. But Saletan is intensely analytical in his previous writings (including a well-received book on the abortion debate). He seems to look at this issue and similar ones as existing on a continuum, where we must balance legitimate needs with moral considerations. And so we get ethics, something that we can change to meet social needs and the truths revealed by science.