An e-mail:
The “brain-birth” criteria proposal is absurd. The reason brain death is used as a marker for death is not that brain activity is what really matters about human beings, but that the cessation of all brain activity is taken to be an irreversible and final end to any organismic functioning. Individual organs can be kept alive after brain death, but there is no unified living organism, and (this is the key) there never will be again–so it is a moment at which it is appropriate to declare death and, if the individual had previously consented, to remove organs for transplantation into others. But let’s be clear: if we thought the brain-dead person would awaken 9 months later, we would not take his organs. And that is the condition of the embryo: it is alive, developing, fully human if not yet fully mature, and on a course to maturity, the same course we all traveled to get here. The whole point of the brain-death criteria we use to mark death (criteria developed by Leon Kass and Alex Capron in 1972) is irreversibility. And that irreversibility is decidedly absent in the case of the developing embryo. To treat “brain birth” as the marker of the beginning of personhood is to fetishize the brain in a way that leads in all sorts of bad directions I am sure John Hood would want to avoid.