Brain transplantation, personal identity and medical ethics.

Why, readers might ask themselves, does this issue of the journal contain a paper on brain tissue transplan-tation and personal identity'-what is the connection between this and medical ethics, the journal's subject matter? Certainly the paper does not address the usual medical ethics issues associated with transplan-tation, such as benefits and harms to recipients, donors and society; respect for autonomy of recipients and donors or their proper proxies; use of different sorts of donors including fetuses, animals and living people; just distribution of resources whether in therapy or research; respect for people's rights; issues oflegal justice, or ethical problems associated with the concept and criteria of brain death. Instead the paper by Dr Northoff examines in considerable detail arguments deployed for and against the claim that brain tissue transplants, currently used in experimental treatments for Parkinson's disease, alter the personal identity of the recipients. At its most dramatic and troublesome the relevance of this issue of personal identity is a major one for medical ethics, for brain transplantation might radically alter the recipient's personality, perhaps even impose on the recipient an entirely new personality, notably the personality of the donor. Indeed, if we consider the so far science fiction scenario of whole brain transplantation, referred to by Dr Northoff as a contrast to brain tissue transplantation, imposition of a new personality seems precisely what would happen, if we insist on thinking of such an operation as brain transplantation rather than, as seems conceptually more accurate, whole body transplantation from a brain dead donor to an isolated brain recipient. For it seems difficult to refute the claim that if it ever became possible successfully to transplant a complete and functioning brain from one human being into another, the procedure would involve donating to a person still present in a living brain a new body from a brain dead donor whose own dead brain had been removed. Thus if Susan's living complete brain was successfully transplanted into the skull of George's body (minus George's brain-dead brain) it would be Susan who survived, though in an uncomfortable new guise-for in her mirror and to everyone else she would appear to be George. This sort of imaginary scenario would clearly have important medico-moral implications if it were ever to become technically possible to carry out such transplants. The confusion and distress of family and friends of the dead person whose body would live on …