More on the moral status of embryos

William Saletan has reviewed a recent book, Embryo: A Defense of Human Life, by Robert George and Christopher Tollefsen. According to the review (I have not read the book, but may do so) the book is an attempt to establish and defend the legal rights of embryos, from conception, based on science, not religious considerations. According to a different article by Saletan, George and Tollefsen believe that not only should embryonic stem cell research and, presumably, some kinds of contraception, be banned, but so should the current practices of removing embryonic cells from, say, an eight-cell embryo for diagnostic, or other purposes, or the production of several embryos for in vitro fertilization.

Saletan was sympathetic, but not convinced. I can't buy the central premise of the book, either. One fundamental scientific fact argues against saying that fertilization is the point at which a new human life is established, distinct from its mother, and all others, namely that there are identical births -- persons who both (or all) came from a single fertilized egg. There are also other scientific facts, which Saletan considers, which cast doubt on that premise. George and Tollefsen have responded to Saletan, here.

If a human fertilized egg can naturally split, and form two or more new humans, it is impossible to say that a human fertilized egg is always a new distinct individual, based on science. It is possible to say so, legally, philosophically, ethically, or for religious reasons, but not scientifically. See here for a previous post on this subject.

Thanks for reading.