Daniel Dennett’s essay is about the roles of brain, body and mind in self-identification. Dennett takes the reader through a list of dizzying circumstances in which the brain is separated from the body and yet the two are in communication through sophisticated technology. The central question in a situation like this is the location of the individual across temporal and spatial scales. Given the speed-of-light communication between the terminals in his skull and the separated brain, the subject’s experiences only suffer a small time lag. The really important philosophical questions, then, arise out of spatially locating the ‘I’ in this unusual configuration of one individual.
Dennett suggests various methods of logic and training through which the distended individual can retain his personhood and function as he is used to. Dennett chooses himself as the case study of these thought experiments. For the sake of this acclimatization project, the body is named Hamlet and the brain (laid in the controlled environment of a lab) is named Yorick. Just as a worker in a factory can simulate the operation of a robot, Yorick can train himself to regard Hamlet as its extension. But unlike normal human experience, a sudden switching-off of electrical supply to Yorick can induce a state of comatose. Likewise, switching electricity back on can bring Dennett back to active life.
Dennett makes an ironic observation that in a brain-transplant operation, it is the donor who retains his identity and not the recipient. In this respect, it is more apt to call it a body-transplant operation. Hence assigning personhood to Hamlet is most dubious. Assigning that status to Yorick is less problematic, but still not fully convincing. Resorting to the generalized claim that ‘Dennett is wherever he thinks he is’ brings its own share of puzzles to the equation.
Dennett then proposes a thought experiment wherein Hamlet is sent down a radioactive tunnel for a search operation. For the utility of the experiment, he is contrived to be trapped and lost. It later transpires that he is ‘dead’. The moment of this death is revelatory, for at that instant, the ‘soul’ of the undivided individual travels at the speed of light to rest in Yorick. Dennett seems to suggest that the soul is essentially a concept of the mind/brain. This point has implications for philosophy and theology.
Further ethical conundrums arise when a replica is made of Yorick (named as Hubert). The complications multiply when a replacement for Hamlet is also introduced (named Fortinbras). Apart from straightforward questions of legality and rights associated with an individual, numerous moral dilemmas are thrown up by these complexities. For example, can the re-doubled identity of Dennett carry on living two separate lives simultaneously? What if Dennett decides to terminate one copy and live through the other? Does he have the right? Does not it amount to murder?
I my view this is one of the best scientific essays I have read in recent years. It is so rich in creativity and imagination. It also employs an easy jargon free language for explaining nuanced cognitive science. Dennett exposes fascinating possibilities for brain-body co-existence in the essay. We are thereby made to sit up and think about our own identity and personhood.