Suppose I invite you to enter a teletransporter for an exciting adventure in space travel. In this teletransporter a copy will be made of every cell in your body. Whilst your brain and body are destroyed on Earth, a new being, a facsimile, will appear almost instantly on Planet Zog. No need for a tedious journey in a space craft. The recreated person on Planet Zog will look indistinguishable from you, it will have all your memories?
But will it be you?
‘Personal Identity’ is one of the most puzzling areas in philosophy. Many philosophers have grappled with it, from John Locke in the 17th Century to Derek Parfit in the 20th.
To test our intuitions about personal identity, philosophers have come up with weird and wonderful thought experiments. Locke asked us to imagine that a prince and a cobbler swapped souls, so that the memories of the prince were in the body of the cobbler and vice-versa. Parfit asked us to imagine what would happen if a brain was split in two, with the two hemispheres being implanted in two separate bodies.
There’s much at stake; the issue matters. Your position on Personal Identity may affect how you regard the past – should a person be punished for an act that was committed a decade earlier? It may affect how you view the future – should you bother to put money into a pension scheme or splurge everything so as to have fun today? How you view Personal Identity might even affect your attitude to death.