Whose Identity Would A Person Have If Their Head Were Transplanted?

The first successful head transplant has not been performed yet. Many complications could happen during the procedure, but, have we asked ourselves: if the surgery were successful, who would wake up?

Suppose two people, Ted and Maria, are driving through a highway when suddenly they hit a truck. In the accident, Maria’s body got so damaged that only her brain survived. Conversely, Ted’s body was left almost unscathed; but his brain was harmed beyond repair. Suppose that after many hours of intense surgery and using the latest technologies, the doctors managed to transplant Maria’s brain into Ted’s body. A few weeks later the patient wakes up at the hospital. The question then is: who woke up?

Questions like these will soon become more relevant than ever: they will present legal, moral, and personal crises which we’ll have trouble to deal with. Already Sergio Canavero, an Italian neurosurgeon, and the orthopaedic surgeon Xiaoping Ren have published a strategy to perform the world’s first head transplant, hoping to perform the surgery within the next few years on ready volunteers. 


So, how can we go about answering? Philosophers have debated the issue of personal identity for centuries, ever since John Locke (1632-1704) first talked about it in An Essay Concerning Human Understanding (1689). Locke himself believed that personal identity is defined by the continuity of our memories and thoughts, not by any conception of soul or body. If this is true, we are our memories rather than organisms or human animals. Clearly, this idea runs into terrible problems when we consider people with some sort of memory impairment, such as people with Alzheimer’s or amnesia. If Locke were right, then they would not qualify as the same entities as they were when healthy. On the other hand, if by some future technology we could replicate memories, we could have two different organisms both of whom would be the exact same person. Most thinkers disagree with Locke. 


In Maria and Ted’s case, many have suggested it’s Maria who wakes up, since it’s her brain that survives. This means the patient will likely have Maria’s memories, thoughts, fears and desires. For Locke, this is more than enough. But there are some people, such as Eric Olson (from the University of Sheffield), who believe we are organisms, specifically animals. Memories are not animals, so what we remember has no bearing on who we ultimately are, according to Oslon. The brain is an organ, and just like a heart is merely transplanted into a person’s chest, so is a brain merely transplanted into a person’s body. It is the body that matters in this case. If this is true, then Ted is the one who wakes up. 

We could also say that neither Ted nor Maria wakes up. The patient becomes a whole new organism when the transplant takes place. Or, alternatively, we can say that both wake up: part of one and part of the other, in which case they are both legally alive still. Either of these alternatives represent legal, moral, and metaphysical nightmares. The bottom line: there is no easy answer.

Maybe our intuitions regarding these matters are just not well grounded yet, and we might need to challenge our ordinary ways of thinking about identity. Consider, however, the deep implications of our beliefs. If something like this happened to you or to someone close to you, how would you deal and cope with that situation, beyond the theoretical aspects of it? Perhaps soon enough, we’ll find out as a society; though hopefully none of us will have to face it directly. 

Photos by Thomas A. Ganderson