I’m skeptical that continuity of personal identity is actually real, beyond a social consensus and a deeply held evolved instinct. I don’t expect there are metaphysical markers that strictly delineate which person-moments are part of “the same” ongoing person through time. So hypothetical new scenarios like teleportation, brain emulation, clones built from brain scans (etc) are indeed challenging—they break apart things that have previously always gone together as a bundle.
Even so, physical continuity of the brain involved seems like a reasonable basis for that consensus. Or at very least some kind of casual connection between one person-moment and the next. Whereas “by pure blind chance I briefly occupied the same mental state as someone outside my light cone” still just seems confused.
There are several arguments for psychological continuity over time (involving memories and personality traits) rather than physical continuity. E.g. teleportation (already John Locke made basically the teleportation argument except with resurrection in heaven) and cases like dissociative identity disorder or similar pathological cases where physical continuity seems largely maintained while personal identity arguably isn’t. There are also hypothetical cases: If consciousness wasn’t tied to atoms, and body swap like in fiction was possible, we would still call it “a person swapping bodies” instead of “a person swapping minds”. Though Boltzmann brains seem to be an argument in favor of physical continuity.
I’m skeptical that continuity of personal identity is actually real, beyond a social consensus and a deeply held evolved instinct. I don’t expect there are metaphysical markers that strictly delineate which person-moments are part of “the same” ongoing person through time. So hypothetical new scenarios like teleportation, brain emulation, clones built from brain scans (etc) are indeed challenging—they break apart things that have previously always gone together as a bundle.
Even so, physical continuity of the brain involved seems like a reasonable basis for that consensus. Or at very least some kind of casual connection between one person-moment and the next. Whereas “by pure blind chance I briefly occupied the same mental state as someone outside my light cone” still just seems confused.
There are several arguments for psychological continuity over time (involving memories and personality traits) rather than physical continuity. E.g. teleportation (already John Locke made basically the teleportation argument except with resurrection in heaven) and cases like dissociative identity disorder or similar pathological cases where physical continuity seems largely maintained while personal identity arguably isn’t. There are also hypothetical cases: If consciousness wasn’t tied to atoms, and body swap like in fiction was possible, we would still call it “a person swapping bodies” instead of “a person swapping minds”. Though Boltzmann brains seem to be an argument in favor of physical continuity.