Personal Identity—Summary Notes

  • The Puzzle of Personal Identity

    • Question: What makes you the same person over time despite changes to body, mind, and memories?
    • Focus: conditions for sameness over time; many proposed solutions have surprising consequences.

  • Ship of Theseus (analogy)

    • A ship rebuilt piece by piece can seem the same ship; raises the question of what constitutes identity.

  • Three traditional solutions to the puzzle

    • Body solution: same body = same person.
    • Mind (soul) solution: same mind = same person.
    • Memory solution: same memories = same person.

  • Locke’s contribution

    • John Locke argued for a memory-based account of personal identity.
    • He also defined what a “person” is and linked identity to psychological continuity and memory.
    • He challenged both the body and mind solutions with thought experiments.

  • The Body Solution

    • Claim: continuity of the same body guarantees sameness of person.
    • Objection: a prince could inhabit a cobbler’s body and still be the same person, challenging bodily continuity as the criterion.

  • The Mind Solution

    • Claim: continuity of the same mind (or soul) guarantees sameness.
    • Objection: a mind could migrate across different historical persons (e.g., Napoleon), undermining personal identity.

  • The Memory Solution (Locke’s proposal)

    • Claim: sameness follows from memory continuity; you are the same if you can remember being the past self.
    • Emphasizes first-personal, episodic memory; not all memories are accessible.

  • Memory and identity: how it works

    • Identity is grounded in a chain of memories linking present and past selves.
    • Example: remembering playing against Mark in tennis justifies being the same person as the one who played then.
    • Chains can be indirect: you may remember events through a series of remembered memories over time.

  • Problems for the Memory Solution

    • Forgetting, amnesia, drunkenness, sleep disrupt memory continuity.
    • It is unclear how to handle cases where memory is unavailable (e.g., asleep vs awake).
    • Locke worried about memories we cannot retrieve yet we still feel sameness across states.

  • What stays the same?

    • Despite radical changes to psychology and physiology, we intuitively remain the same person.
    • Debates persist over whether sameness rests on memory, mind, body, or something else.

  • The Self as Illusion

    • Some philosophers argue we cannot say anything informative about what makes a person the same over time.
    • The self may be an illusion or fiction—useful for organizing experiences but not a real underlying entity.

  • Nagasena on the Self (Chariot analogy)

    • The self is like a chariot: composed of parts (wheels, axles, hubs); no single essence beyond its parts.
    • Experiences constitute the self; there is nothing persisting independently of those experiences.

  • Hume on the Self

    • David Hume: when looking inward, only a bundle of changing perceptions is found.
    • The idea of a fixed self is fictitious; the self is a useful fiction built from a stream of experiences.

  • Practical note: legal significance of persons (Locke’s context)

    • Persons are seen as thinking, rational agents with memories and responsibilities for past actions.
    • Legal blameworthiness ties to being the same person across time, via memory/personal continuity.

  • Key takeaways for exam quick recall

    • Identity over time is a puzzle because people undergo substantial changes yet seem the same.
    • Body, mind, and memory are the main traditional criteria; each faces counterexamples.
    • Locke advances the memory solution, linking personal identity to memory continuity.
    • Real-world implications include memory continuity for responsibility and rights.
    • Alternative views: self as illusion or fiction; self may not be a single persisting entity.