I get the impression Chalmers is using something like Conceivable1 for the "zombies are conceivable" part of the arguments then sneakily switching to something more like Conceivable3 for the "conceivable, therefore logically possible" part.
I suspect you already know this, but just in case, in philosophy, a zombie is an object that can pass the Turing test but does not have internal experiences or self-awareness. Traditionally, zombies are also physically indistinguishable from humans.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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