Is our personal identity just the particular make up of our physical bodies at a particular point in time? And if so, would a teletransporter that replicated our physical bodies on Mars preserve our personal identity? Thought experiments and transhumanist sci-fi technological dreams such as this are deceptive means of doing philosophy and should be kept in Hollywood and marketing campaigns, writes Nicholas Agar. 

In his 1984 philosophical classic Reasons and Persons Derek Parfit tells a story about a fantastical futuristic technology – the Teletransporter.