>> But until we have a solid theory about consciousness, with the possibility of proving a claim to be objectively true or false, all we have are assumptions.

> Your wording implies that all the different possibilities are equally probable.

No, my wording only suggests that there is more than one possibility.

> We "assume" that the explanation for conscious experience lies in materialism because it is the most probable answer given what we know.

Assigning probabilities to assumptions, in the absence of a formal theory, has obvious risks. A formal theory can be exploited to produce real probabilities, probabilities that can themselves be compared to experiment and possibly become the basis for a falsification.

>> But consciousness is by definition a non-material phenomenon, so that's the wrong approach.

> This isn't very useful.

It's a critical point. If what's being measured is ethereal, then a physical measurement is innately misleading. Consider our mathematical abilities, and consider the relation between consciousness and a propensity for mathematical thought. Solely to make a point I might suggest a consciousness gauge that relies on the ability to reason mathematically -- more math, more consciousness. Sort of like the famous mirror test, but at a higher level: a certain animal is conscious to the degree that it can reason mathematically. But mathematics, and consciousness, are both nonmaterial properties, therefore (a) this makes a math scale an appropriate measure of consciousness, and (b) it creates yet another difficult, nonmaterial measure of consciousness.

If we instead measure the speed at which an animal solves a certain easily measured problem, the basis for many IQ tests over the years, that test will eventually be solved more efficiently by a computer. If we measure consciousness by the ability to pass some kind of Turing test, same answer.

My point? Tests of consciousness tend to be material quantifications of something non-material. These tests are easily passed by present and future computers, simulacra -- unless, of course, we begin to assign consciousness to computers. That's an interesting approach, but it does lead to reasonable doubt about the basic premise that the human (or dolphin, or gray jay) brain is the seat of consciousness.

> The problem with the metaphysical types is that you propose some exotic mechanism simply because you can't imagine how natural phenomena could give rise to consciousness.

It's the other way around, exactly the other way around. The materialist position exists because it's accessible to conventional experimental methods. It may turn out to be perfectly correct, I emphasize that, but it exists only because we don't have the tools to correlate consciousness with other measures using some other approach, and even if we did, there might be no point to the exercise if it didn't lead to objective evidence, evidence on which different observers agree, evidence on which most modern science depends.

> This is simply a failure of imagination on your part.

I hope you recognize the humor in that position. It is the materialist outlook that represents a failure of imagination. It is an intentional limitation of inquiry to make the outcome fit into conventional categories, into publishable experimental science. It's why psychological research has the reputation it does.

Einstein's brain wasn't physically (materially) significantly different than the brains of many other men and women. Yet he produced results that (a) sprang from "consciousness", indeed to many it represents a measure or criterion of consciousness, (b) arose in the realm of mathematics, clearly a Platonic realm, and (c) have no materialist explanation.

Think of all the remarkable outcomes of conscious behavior that aren't correlated with a measurable material cause, that are orthogonal to material measures. Then think of all the ways we have of measuring consciousness that can be faked by a computer.

My point? It's the materialist outlook that represents a failure of imagination, and it only exists because it allows a kind of faux science to address consciousness, as though the latter could realistically be reduced to material quantification.