Yes, it would be difficult to hold belief (3) and also believe that p-zombies are possible. By (3) all truthful human statements about self-OC are causally downstream from self-OC and so the premises that go into the concept of p-zombie humans are invalid.
It’s still possible to imagine beings that appear and behave exactly like humans even under microscopic examination but aren’t actually human and don’t quite function the same way internally in some way we can’t yet discern. This wouldn’t violate (3), but would be a different concept from p-zombies which do function identically at every level of detail.
I expect that (3) is true, but don’t think it’s logically necessary that it be true. I think it’s more likely a contingent truth of humans. I can only have experience of one human consciousness, but it would be weird if some were conscious and some weren’t without any objectively distinguishable differences that would explain the distinction.
Edit: On reflection, I don’t think (3) is true. It seems a reasonable possibility that causality is the wrong way to describe the relationship between OC and reports on OC, possibly in a way similar to saying that a calculator displaying “4” after entering “2+2″ is causally downstream of mathematical axioms. They’re perhaps different types of things and causality is an inapplicable concept between them.
Yes, it would be difficult to hold belief (3) and also believe that p-zombies are possible. By (3) all truthful human statements about self-OC are causally downstream from self-OC and so the premises that go into the concept of p-zombie humans are invalid.
It’s still possible to imagine beings that appear and behave exactly like humans even under microscopic examination but aren’t actually human and don’t quite function the same way internally in some way we can’t yet discern. This wouldn’t violate (3), but would be a different concept from p-zombies which do function identically at every level of detail.
I expect that (3) is true, but don’t think it’s logically necessary that it be true. I think it’s more likely a contingent truth of humans. I can only have experience of one human consciousness, but it would be weird if some were conscious and some weren’t without any objectively distinguishable differences that would explain the distinction.Edit: On reflection, I don’t think (3) is true. It seems a reasonable possibility that causality is the wrong way to describe the relationship between OC and reports on OC, possibly in a way similar to saying that a calculator displaying “4” after entering “2+2″ is causally downstream of mathematical axioms. They’re perhaps different types of things and causality is an inapplicable concept between them.