The equivalent of the Zombie World, for questions of identity/continuity, is the Soul Swap World. The allegation is that the Soul Swap World is microphysically identical to our own; but every five minutes, each thread of consciousness jumps to a random new brain, without the brains changing in any third-party experimentally detectable way. One second you’re yourself, the next second you’re Britney Spears.
This scenario strikes me as logically incoherent—for much the same reason as I don’t buy “body swap” scenarios in science fiction.
There is no such thing as a “me” that can jump between brains. If “jumping between brains” means something, then it could mean two things:
For me to subjectively experience “waking up as Britney Spears”, I’ll need to retain the memories of being the current me up to that point. That would mean that Britney Spears’ brain would need to be physically altered to inscribe my memories, rather than hers, which contradicts our premise that no physical attributes are being altered.
If “I” end up in Britney Spears’ body but lose “my” original memories, and likewise “Britney Spears” becomes me, then it no longer makes any sense to speak about preservation of personal identity, any more than it makes sense to ask “If we simultaneously yanked every plank composing the Ship of Theseus out of its space, and warped different planks into their space to make a ship of a completely different shape, would it still be the same ship”? If “being the same ship” or “being the same person” means anything at all, then it is a different ship, and likewise, the hypothetical “me in Britney Spears’ body but with Britney Spears’ memories instead of mine” is exactly the same person as Britney Spears. There is no incorporeal identity tag that we can attach to minds, any more than we can do so for electrons.
If “I” end up in Britney Spears’ body but lose “my” original memories, and likewise “Britney Spears” becomes me, then it no longer makes any sense to speak about preservation of personal identity
That is the intended conclusion from the Soul Swap World thought-experiment.
This scenario strikes me as logically incoherent—for much the same reason as I don’t buy “body swap” scenarios in science fiction.
There is no such thing as a “me” that can jump between brains. If “jumping between brains” means something, then it could mean two things:
For me to subjectively experience “waking up as Britney Spears”, I’ll need to retain the memories of being the current me up to that point. That would mean that Britney Spears’ brain would need to be physically altered to inscribe my memories, rather than hers, which contradicts our premise that no physical attributes are being altered.
If “I” end up in Britney Spears’ body but lose “my” original memories, and likewise “Britney Spears” becomes me, then it no longer makes any sense to speak about preservation of personal identity, any more than it makes sense to ask “If we simultaneously yanked every plank composing the Ship of Theseus out of its space, and warped different planks into their space to make a ship of a completely different shape, would it still be the same ship”? If “being the same ship” or “being the same person” means anything at all, then it is a different ship, and likewise, the hypothetical “me in Britney Spears’ body but with Britney Spears’ memories instead of mine” is exactly the same person as Britney Spears. There is no incorporeal identity tag that we can attach to minds, any more than we can do so for electrons.
That is the intended conclusion from the Soul Swap World thought-experiment.