Rather a late comment… but this response to Goplat reminds me of one of David Lewis’s arguments for modal realism. Namely, he argues that “merely possible” people have exactly the same evidence that they are “real” as we do (it all looks real to them), and hence we ourselves have no evidence that we are “real” rather than merely possible.
An objection to this is “No! Merely possible people DON’T have evidence that they are real, because they don’t exist. They don’t have any evidence at all. They WOULD have the same evidence that we do if they DID exist, but then of course they WOULD be real.”
A similar objection is that the wave function amplitudes can’t do any real computation (as opposed to possible computation) unless they have real particles to compute with. So any people who find themselves existing can infer (correctly) that they are made out of real particles and not mere amplitudes.
It always amuses me that the particle motions in Bohm’s theory are described as “hidden variables”. Rather to the contrary, they are the ONLY things in the theory which are NOT hidden (whereas the wave function pushing the particles around is...)
Rather a late comment… but this response to Goplat reminds me of one of David Lewis’s arguments for modal realism. Namely, he argues that “merely possible” people have exactly the same evidence that they are “real” as we do (it all looks real to them), and hence we ourselves have no evidence that we are “real” rather than merely possible.
An objection to this is “No! Merely possible people DON’T have evidence that they are real, because they don’t exist. They don’t have any evidence at all. They WOULD have the same evidence that we do if they DID exist, but then of course they WOULD be real.”
A similar objection is that the wave function amplitudes can’t do any real computation (as opposed to possible computation) unless they have real particles to compute with. So any people who find themselves existing can infer (correctly) that they are made out of real particles and not mere amplitudes.
It always amuses me that the particle motions in Bohm’s theory are described as “hidden variables”. Rather to the contrary, they are the ONLY things in the theory which are NOT hidden (whereas the wave function pushing the particles around is...)