Personal Identity

General Problem The River Quantum Identities The Ship of Theseus You can’t step into the same river twice Quantum Identities Discrete states don’t allow tracking of identities The Ship of Theseus I’ve had this axe for years : I’ve had to replace the handle three times and the head twice.

Personal Problem Personal identity through time Transporter Splitter Am I as a baby the same as me as an adult? Transporter Are you the same person after being teleported? Splitter Who is the real Riker?

Two Possibilities Bodily Continuity Person X at t1 is person Y at tn if there’s a sequence of persons from t1, t2, … to … tn-1, tn who are all identical The important identity is bodily characteristics. Identity is a transitive relationship If A1 = A2, A2 = A3, …, An-1 = An Then A1 = An

Two Possibilities Psychological Continuity The important identity is psychological.

Two Possibilities Locke For should the Soul of a Prince, carrying with it the consciousness of the Prince’s past Life, enter and inform the Body of a Cobler as soon as deserted by his own Soul, every one sees, he would be the same Person with the Prince, accountable only for the Prince’s actions: But who would say it was the same Man?

Problems with Memory Incompleteness Do lapses of memory indicate lapses of identity? Inaccuracy I remember being Napoleon – But I’m not him Problems of the Self

Problems with Memory Hume For my part, when I enter most intimately into what I call myself, I always stumble on some particular perception or other, of heat or cold, light or shade, love or hatred, pain or pleasure. I never can catch myself at any time without a perception, and never can observe any thing but the perception.