Here's an argument related to Eliezer's point about the need to have a substantive model of consciousness before you can model removing it from the world:

Consider a hypothetical person, call him "Al." On the assumptions of property dualism, Al comprises or instantiates certain "formal" natural properties Φ and certain "intrinsic" natural properties Ψ.

The property dualist postulates that Φ and Ψ are necessary and sufficient conditions for consciousness.

Yet we can "clearly and distinctly" conceive of zombie-Al, who is a duplicate of Al in respect of both Φ and Ψ, but who is nonetheless phenomenally void.

Thus, we are right back where we were before Ψ was even posited. Therefore, Ψ is theoretically vacuous.