Derek Parfit: 4 ideas worth knowing

4 ideas from Derek Parfit, each explained in a minute and credited to the original work. Free on Savvy.

Would teleportation kill you first?
Derek Parfit imagined a machine that destroys your body on Earth while instantly recreating an exact atomic copy on Mars. Is the copy you — or did the original you die and get repl…
— Derek Parfit, Reasons and Persons
Enough barely-worth-living lives can outscore a small thriving population
Derek Parfit showed that if you value a population by total wellbeing, a modest group living wonderful lives can always be beaten by an unimaginably larger population whose lives a…
— Derek Parfit, Reasons and Persons
Split your brain into two working bodies — which one is really you?
Parfit imagined a brain divided in half, each half transplanted into a different body, both waking up with his full memories and personality. Neither can be identical to the origin…
— Derek Parfit, Reasons and Persons
A choice can leave someone worse off than never existing — but never worse for them
Derek Parfit's non-identity problem points out that policies affecting future generations, like depleting resources, don't harm any specific future person, because a different choi…
— Derek Parfit, Reasons and Persons

Five ideas worth knowing, every week