Between an Embryo and Life #
I just noticed a rather interesting argument that’s broken out between Slate’s William Saletan and the authors of Embryo, Robert George and Christopher Tollefson. The rather civil confrontation is over when an embryo becomes a distinct person. It began in Sunday’s Times Book Review, with a rebuttal at the National Review, and Saletan’s response to the rebuttal at Slate (title link), from which this bit is taken.
The embryo does have a program, and its launch does mark the sharpest line in human development. But even that line is dotted. Transitions that are supposed to happen at fertilization happen after or without it. As the embryo grows toward maturity, it becomes more like a person. Its individuality solidifies. Its body plan and nervous system develop. Its boundary with the mother closes. It placenta passes away. These, too, are lines in human development. It’s reasonable to build moderate IVF, stem-cell, and abortion policies along such lines, even if, like the rest of biology, they’re not absolutely clear.