I’m reading Being you and they make a similar point to the one you make about H20 and XYZ. It’s part of their argument against p-zombies:
Here’s why the zombie idea is supposed to provide an argument against physicalist explanations of consciousness. If you can imagine a zombie, this means you can conceive of a world that is indistinguishable from our world, but in which no consciousness is happening. And if you can conceive of such a world, then consciousness cannot be a physical phenomenon.
And here’s why it doesn’t work. The zombie argument, like many thought experiments that take aim at physicalism, is a conceivability argument, and conceivability arguments are intrinsically weak. Like many such arguments, it has a plausibility that is inversely related to the amount of knowledge one has.
Can you imagine an A380 flying backward? Of course you can. Just imagine a large plane in the air, moving backward. Is such a scenario really conceivable? Well, the more you know about aerodynamics and aeronautical engineering, the less conceivable it becomes. In this case, even a minimal knowledge of these topics makes it clear that planes cannot fly backward. It just cannot be done.
It’s the same with zombies. In one sense it’s trivial to imagine a philosophical zombie. I just picture a version of myself wandering around without having any conscious experiences. But can I really conceive this? What I’m being asked to do, really, is to consider the capabilities and limitations of a vast network of many billions of neurons and gazillions of synapses (the connections between neurons), not to mention glial cells and neurotransmitter gradients and other neurobiological goodies, all wrapped into a body interacting with a world which includes other brains in other bodies. Can I do this? Can anyone do this? I doubt it. Just as with the A380, the more one knows about the brain and its relation to conscious experiences and behavior, the less conceivable a zombie becomes.
I’m reading Being you and they make a similar point to the one you make about H20 and XYZ. It’s part of their argument against p-zombies: