Long before neuroscientists took the first tentative steps toward brain-tissue transplants (let alone dared to think about whole-brain transplants), mischievous philosophers were plumbing the consequences of such 21st century surgery. "In a brain-transplant operation, is it better to be the donor or the recipient?" these wags asked. To put it another way, if you and Tom manage to swap brains, who is now the real you? The man with your brain attached to Tom's body or the man with Tom's brain joined to your body?
The real you, it can be argued, is the man with Tom's body; he's the one...