Christina Conroy (Morehead State U): Branch-Relative Identity: Quantum mechanics implies a ranching metaphysics (the many-worlds interpretation).
But in multiple branching worlds an individual pre-branching cannot be identical to all of his successors and therefore cannot be identical to any of them. Parfit thinks in such cases you either survive as one, both, or not at all. Parfit opts for “both.”
Conroy argues survival does not require identity. So Hugh0 is identical to Hugh1 relative to the branch in which Hugh1 exists. This ensures identity is reflexive (Hugh1=Hugh1), symmetric, and transitive in the required way.
Eoin O’Connell (Manhattan): Philosophers (e.g., Warren, Singer, Tooley) have offered various lists of intrinsic properties requisite for personhood. But how do know why these properties are required without being able to identify persons first? Secondly, to what degree must they be instantiated?
Nor can we trust intuitions on who is a person, since these are manifestly unreliable. So we should inferences made from relationships with those with whom we share experiences.