Then again, there are some topics that seem to turn even the most brilliant minds to mush. (These seems to be the same topics for which, incidentally, there could be no epistemically relevant "authority.") Hence, your disagreement with Aumann out-of-hand, for instance.

Thus I'd think some kind of topic-sensitivity is lurking in your rule as well.

Tanasije, you said "Quinean empiricism," not empiricism simpliciter. Quine was at least epistemologically physicalist (to whatever degree physicalism can be so restricted), so I thought adding realism made the point cleanly enough.

Anyway, I'm arguing that the reason successful, productive scientists presume "the world can in some measure be described and understood" is that they presuppose a rough-and-ready physicalism with regard to the phenomenon they study. (As I see it, the lack of any scientifically productive appeal to "intrinsic properties" or the like as an explanans is suggestive enough.) The claim, then, that there's no logical contradiction in doing otherwise is beside the point I was making.

I'll otherwise submit. Last word's yours if you want it.

"[Physicalism] is just yet another metaphysical position."

I don't think that's correct. Scientists presuppose naturalism when they study a phenomenon. For historical reasons, a special word has been coined for the standard presupposition when it is applied in the context of consciousness. That word is 'physicalism.' In this sense, physicalism is merely a sound methodological induction (as is the subsidiary induction that methodological naturalism tells us something about the likely ontological constitution of the world).

Alternatively, 'physicalism' is also the name for a philosophical project that aims to give a formal account of, or justification for, this presupposition (both in its methodological and ontological guises). There are some who insist that this philosophical physicalism somehow must amount to an a priori thesis, but by my lights there isn't any good reason to do so.

Best exchange:

GENERAL FRED: Are you sure?

SCIENTIST: As sure as we can be in the total absence of evidence.

Brutal.

Tanasije Gjorgoski, I don't quite understand the argument. Science doesn't "a priori deduce facts." It generates and tests explanatory structures that purport to account for observed regularities. Physicalism (ontological naturalism) isn't an a priori theory of scientific methodology; it's an induction from the success of the scientific project. (Science generally proceeds within a physicalist framework because physicalism has worked well, whereas its competitors haven't. Operationally, this means that when scientists grapple with the phenomenon, the presumption is that whatever scientific explanation there is to be had resides within the physicalist framework.) The zombie argument, then, is an a priori argument that seeks to defeat this induction over the phenomenon of consciousness.

Sorry, that last comment was mine; didn't want to leave it unsigned.

Right. It's one thing to send up the inanity of the Jesus myth. But it's quite another to cast Mary as sexually liberated. Eliezer, how dare you!