Claims, then, that higher-brain death is death simpliciter, that a person who has ceased having higher-order brain functions is no longer a person, appear to me to be utterly irrational and arbitrary. They are a denial of the fairly obvious fact that human personhood is exhibited in all our vital functions. They are a flight from human animality, a pretense that higher-order thought is all that there is to being a human person. (It is an old story. The excuse that some human persons should not be regarded as persons because they do not properly exhibit rationality is one of the oldest moral dodges in the book; it has been used to justify slavery, racism, sexism, sterilization of the mentally disabled, and the like. If you are going to go this route, you had better have a damn good argument for doing so.)Brandon considers the higher-brain death position (my position) to involves treating the forebrain as the homunclar center of personhood. In the second post, he wrote:
[The higher-brain death view] is essentially a view under which a person is a humunculus in the brain; the humunculus is the person, and because of this, when the humunculus goes away, the person goes away.Ultimately, I don't think that Brandon can treat the higher-brain death position as arbitrary without treating his own as arbitrary as well. The reason he fails to see this is that he misunderstands the higher-brain death position. Ultimately, the only difference between them is that they take different views of personhood from the start, but the higher-brain death position does not take the one that Brandon claims. At least, it does not do so in my own version of it, which I do not think is all that idiosyncratic.
An individual human person is differentiated from other human individuals, as well as nonhuman individuals, by a collection of memories, beliefs, knowledge, skills, and tendencies. In other words, what defines an individual person is a history. That history is, by and large, contained in the cerebral cortex and surrounding brain areas, along with the cerebellum. The hind-brain and mid-brain structures that may survive higher-brain death may contain some simple motor programs and associations, but for the most part, they contain innate reflexes and other programs that, while they allow the body itself to survive, do not provide for any real differentiation between individuals. In higher-brain death, then, all that survives is the basic functioning of the organism, while all of the properties that comprise a particular self, a particular person, are gone. Sure, the physical appearance remains, as do the internal bodily idiosyncrasies of an individual (if you have a bad liver from years of drinking, the liver will remain damaged even with higher-brain death), but these differences do not make an individual person. They make an identifiable body, and survive even complete brain death.
From an empirical standpoint, both ways (Brandon's and mine) of delineating personhood are arbitrary. Both place the line between life and death at empirically verifiable boundaries. What criteria, then, can we use to decide between them? My reason for requiring the possibility of higher-brain functioning is this: I believe that to define personhood as the basic functioning of the organism (e.g., breathing, digestion, blood circulation, etc.), or as anything less than the existence of a neurally-realized history, a set of physical properties of the higher-brain that differentiate and define individuals, is harmful to the dignity of human individuals. It results in the view that all of the things that make us different from one another -- all that makes us who we are -- is superfluous, merely icing on the cake of undifferentiated vital functioning. But ultimately, who we are, what we are, as persons, is more than just breathing, circulation, and digestion; it is a history that is recorded in the configurations of our higher-brain structures. When those are gone, we are not persons; we are merely bodies with life, but no lives.