Τι σε κάνει να παραμένεις ο ίδιος άνθρωπος με την πάροδο του χρόνου; Έχεις αλλάξει από την παιδική σου ηλικία. Το σώμα σου έχει μεγαλώσει. Οι αναμνήσεις σου έχουν ξεθωριάσει. Οι πεποιθήσεις και οι επιθυμίες σου έχουν μεταβληθεί. Κι όμως, είσαι ακόμα ο εαυτός σου. Η προσωπική ταυτότητα είναι η συνέχεια του εαυτού ενός ατόμου με την πάροδο του χρόνου. Το ερώτημα είναι τι στηρίζει αυτή τη συνέχεια. Είναι το σώμα, ο εγκέφαλος, η μνήμη ή κάτι άλλο;

Locke argued that personal identity is grounded in continuity of consciousness, especially memory. If you can remember being a child, you are the same person. Reid objected that this account is circular, since memory presupposes personal identity. Hume argued that there is no enduring self, only a bundle of perceptions. Parfit argued that personal identity is not what matters. What matters is psychological connectedness and continuity, which can come in degrees. These debates matter for ethics and law. Advance directives, organ donation, and end-of-life decisions all depend on assumptions about personal identity. If you are not the same person you were ten years ago, can you be held responsible for what you did then?

Theories of personal identity

• Body. You are your body.
• Memory. You are the continuity of your memories.
• Psychological continuity. You are the continuity of your mental life.
• Bundle. There is no enduring self, only perceptions.

Personal identity is not just a philosophical puzzle. It is a practical question about responsibility, commitment, and care.