Last month on this blog we spent a good deal of time discussing the proposed constitutional amendment in Mississippi to change the legal definition of personhood to include fertilized human eggs. The amendment would have outlawed all abortions (including those resulting from rape or incest), many forms of birth control (including IUDs and morning-after pills), and embryonic research. Fortunately, it was rejected. Yet while it might seem like common sense to most people that fertilized eggs are not persons, such thinking has important implications for the logic of the abortion debate, according to philosopher Gary Gutting: The basic problem is that, once we give up the claim that a fertilized egg is a human person (has full moral standing), there is no plausible basis…