When Ceri Braum accepted the gift of eternal life, this was not quite what she had in mind. Sure, knew that her brain would be removed from her body and kept alive in a vat. She also knew her only connection with the outside world would be via a camera, a microphone and a speaker. But at the time, living for ever like this seemed a pretty good deal, especially compared to living for not much longer in her second, deteriorating body.
In retrospect, however, perhaps she had been convinced too easily that she was just her brain. When her first body had given out, surgeons had taken out her brain and put it into the body of someone whose own brain had failed. Waking up in the new body, she had no doubt that she was still the same person, Ceri Braum. And since it was only her brain that remained from her old self, it also seemed safe to conclude that she was, therefore, essentially her brain.
But life just as a brain strikes Ceri as extremely impoverished. How she longs for the fleshiness of a more complete existence. Nevertheless, since it is her, Ceri, now having these thoughts and doubts, is she nonetheless right to conclude that she is, in essence, nothing more or less than her brain?
--From Baggini, J. 2005. ''The Pig that Wants to be Eaten: 100 Experiments for the Armchair Philosopher.'' London: Penguin Group.