My explanation was a bit confusing, sorry about that! I wasn’t intending for there to be an “original” Mary; she and everyone else only ever existed as a simulation. If we were to assume substrate independence, we’d be fine with saying that the denizens of Sim#1 are conscious.
I think the assumption the argument works from is that the Consciousness Is Computation. The substrate independence of computation , which I don’t doubt, doesn’t prove anything about consciousness without that.
And while Sim#2 Mary is not a P-zombie to the alien, she very much is one to the people in Sim#2.
I guess you’re correct that the right terminology would be that she’s C-zombie, but the people in the simulation can’t know that.
And since we can’t know for sure whether we ourselves are “really” physical, for all intents and purposes we can’t be sure that there is a distinction between P- and C- zombies.
It’s about explanation. Dualism has more resources to explain consciousness than physicalism, which has more resources than computationalism, etc. That doesn’t mean you should jump straight to the richest ontology , because that would be against Occam’s Razor. What should you do? No one knows! But there is no fact that you can explain consciousness with algorithms alone.
Personally, I find physicalist theories of consciousness that don’t include substrate independence quite silly, but that’s a matter of taste, not a refutation.
Computationalism is a particular form of multiple realisability. Physicalism doesn’t exclude it, or necessitate it. Other forms of multiple realisability are available.
My vague gesturing at an argument would be something like this: a brain in a vat is halfway between a physical person and a simulation of one
Err..why? A physical brain that happens to be in a vat is a physical brain, surely?
first by replacing each neuron with a chip, and then by replacing networks of chips with bigger chips running a network, and so on until the whole thing is a chip. Is it really the case that we’re losing the physics?
You are losing the specific physics. Computational substrate independence is a special case of substrate independence , but substrate independence in no case implies immateriality.
ETA
We used to think that the prediction of dark stars meant that Newton’s fact of gravity broke down when it came to light (which was true); but then again, we thought the same about the prediction of black holes and General Relativity. Nowadays, most physicists (probably) don’t believe that white holes exist, despite the fact that they’re just as predicted by GR as black holes, because they find the prospect absurd (in the absence of evidence).
You can be forced into a belief in counterintuitive conclusions by strong evidence or arguments … and you should only believe it on the basis of strong evidence and arguments. The rule is not “never believe in counter intuitive conclusions” .
I think the assumption the argument works from is that the Consciousness Is Computation. The substrate independence of computation , which I don’t doubt, doesn’t prove anything about consciousness without that.
And while Sim#2 Mary is not a P-zombie to the alien, she very much is one to the people in Sim#2.
It’s about explanation. Dualism has more resources to explain consciousness than physicalism, which has more resources than computationalism, etc. That doesn’t mean you should jump straight to the richest ontology , because that would be against Occam’s Razor. What should you do? No one knows! But there is no fact that you can explain consciousness with algorithms alone.
Computationalism is a particular form of multiple realisability. Physicalism doesn’t exclude it, or necessitate it. Other forms of multiple realisability are available.
Err..why? A physical brain that happens to be in a vat is a physical brain, surely?
You are losing the specific physics. Computational substrate independence is a special case of substrate independence , but substrate independence in no case implies immateriality.
ETA
You can be forced into a belief in counterintuitive conclusions by strong evidence or arguments … and you should only believe it on the basis of strong evidence and arguments. The rule is not “never believe in counter intuitive conclusions” .