Sometime Reason contributor John Hood stirs up a tizzy on The Corner with the radical notion that, since it’s the human mind (as opposed to some kind of magic fairy dust sprinked on the 2 percent of our DNA separating us from chimps) that all our ordinary moral categories implicitly recognize as the wellspring of our moral status, perhaps a concept of “brain birth” (by analogy to “brain death”) could help generate some kind of consensus on the perennially thorny abortion question. I don’t think that’ll quite do it—all sorts of organisms have some kind of brain; you need to say something about its content and capacities as well—but it’s at least a good starting point.

Ramesh Ponnuru actually offers a criterion I think is more or less right, if still in need of plenty of specification, though he rejects it without explanation: ” Then we would be making higher mental functions our criterion, and we could say that consistency demands that we not treat the early-stage human being as a person. ” But in the same post, Ramesh also offers this:

Someone could always argue that only “persons” deserve protection, and that there is a class of human beings who are non-persons. So that argument–more philosophical than scientific–also has to be addressed once the scientific confusions are cleared up.

Except, this is precisely backwards. If you’re trying to clear up the science first, of course you’re going to end up confused, because the empirical scientific questions are only interesting insofar as they tell us whether, when there’s some doubt, an organism might meet the specifications philosophy provides us. If it had turned out that what we regarded as “human beings” were actually a whole bunch of different species, or that there were other sorts of organisms with equivalent minds, it would never occur to anybody that this was somehow a huge upset to ordinary moral views about how we ought to treat people. The species category “human” is morally uninteresting. First we need to clear up the philosophical question and figure out what’s relevant to being due moral consideration, and then we turn to science if we need help figuring out whether (say) a paralyzed person retains an inner life of some kind.

Next up is K.J. Lopez, who outsources her contribution to the debate to a reader but, alas, picks a very confused one:

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….But let’s be clear: if we thought the brain-dead person would awaken 9 months later, we would not take his organs.

Now, this is just an atrocious muddle. The second sentence contradicts the first, since the first is, of course, false: Just as a person with a fully functional mind might require extensive intervention to keep the rest of the organism functioning (and, of course, it would require a special sort of moral stupidity to think that this end of a “unified living organism” made it acceptible to kill such a person), a brainless body might well be kept alive with outside assistance for quite a while.

The second, distinct argument is about “irreversibility”: Once the brain’s dead, there’s no coming back. Of course, again, this really means that there’s no coming back for that brain (that one’s other organs were hopelessly damaged—even that one’s brain had to be put in a totally artificial body—would obviously be no reason to withdraw support), which suggests that even people who want to deny it can’t quite get around a commitment to the centrality of the mind. But the distinct idea here is simply the familiar potentiality argument: A dead brain’s gone for good, and… uh… a not-yet-there brain is coming? Once you actually try to state the parallel, it becomes clear how silly it is. You wouldn’t kill a “brain dead” patient who (maybe through nanotech? who knows) might suddenly “come back”. But, of course, you wouldn’t do that because what’s important is the stuff that could come back: the memories and dispositions and desires and projects and everything else that makes us who we are. But here, again, once it’s clear that that’s what matters, it’s scarcely odd to think preserving those things (whose past instantiation willed their continuity) might be important, whereas seeing a new set freshly realized in some particular body isn’t a particularly compelling goal.