book

Reasons and Persons

by Derek Parfit

Parfit's 1984 book uses teleporters, split brains and gradual replacement to argue that personal identity is not what matters in survival. It shows how egoism and common-sense morality defeat themselves on their own terms, and it more or less founds population ethics with the Repugnant Conclusion. Dense and numbered like a proof, it remains the most influential work of analytic ethics of its century.