As I noted in Chapter 3, much of the discussion of brain death involves clinical, legal and historical matters on which the mere philosopher has no expertise. In what follows, then, I am in the main concerned only to report on such matters in so far as I understand them. There is some comment and criticism, some taking sides, but this should be understood as provisional.

Some terms

We are sometimes conscious, sometimes not. We are not conscious when asleep, under a general anaesthetic, in a coma, in pvs, when brain dead and when dead. Some of these unconscious states are permanent, others not. Someone who is conscious is very clearly not dead. Some people are very clearly dead. As I have said, most agree that someone who is conscious at some time was never dead before that time. But there are questions about the condition of various of the people who are, for different reasons, permanently unconscious.

pvs is a term of art. It refers most often to a persistent vegetative state. Someone in such a state is permanently and irreversibly unconscious. Those in PVS reveal no self-awareness and engage in no purposive action, but they will show sleep-wake sequences, give reflex responses, yawn, chew and swallow. They breathe unaided. Some now prefer to unpack PVS as a permanent vegetative state. But there are not two states that need to be distinguished, one permanent, the other merely long-lasting; and most hold that recovery from what appears to be PVS indicates a misdiagnosis of the condition.