biography

Earl Conee and Theodore Sider, Riddles of Existence

Ch. 1: Personal Identity

Two kinds of identity:

• Qualitative identity

• Numerical identity

• The question: What makes one person numerically the same person over time?

Three potential but problematic answers:

• The Soul

• • You are identical with your soul.

  • X is the same person as Y iff X and Y share the same soul.

• Spatiotemporal Continuity

• • You remain the same by occupying the same space-time region.

  • X is the same person as Y iff X and Y are spatiotemporally continuous with each other.

• Psychological Continuity

• • You are identical with a future being iff you are psychologically continuous with that being.

  • X is the same person as Y iff X and Y share the same psychological makeup (memories, beliefs, thoughts, desires, etc.)

Two radical solutions to the duplication problem:

• Derek Parfit: Personal identity is unimportant

• Personal identity is not numerical identity