>Sure, you got me: "materialism" to me means "doesn't contain random bullshit that by its very definition can't even be investigated."

You should stop and think about that. You're essentially saying that your notion of materialism has absolutely nothing to do with any notion of "material". Isn't that kind of odd? It's certainly a long way from the materialism of the 17th century (pre-Newton) which actually had some content to it (i.e. contact mechanics).

>Realize that you're claiming something extraordinary, that there is a fundamentally non-physical effect at work in the brain.

If by non-physical I mean "not accounted for by current laws of physics", then why is this extraordinary?

>How might I "measure" the existence of subjective experience?

I think measure is just an odd verb to use in this context. How do I "measure" whether or not there is milk in the fridge? Well, I look and see. Same with my subjective experience.

>Not really. What you are doing is believing that you are observing your own experience right now.

Ok, and I'm not really seeing the desk, I'm just believing that I'm seeing the desk. Skepticism about perception is fine, but why be more skeptical about your perception of your conscious experience than of your visual or other perceptions?

The other issue here is that believing that you are having a conscious experience is itself a kind of conscious experience, so you can't really wriggle out of it that way. I might be mistaken about the object of my perceptions (ok, maybe it's not really a desk I'm seeing, or maybe I'm dreaming), but I can hardly be mistaken that I am seeing something, or that I am having a conscious experience of something.

>In other words, introspection doesn't prove anything other than that you hold a particular belief.

This obviously leads to a vicious circularity. If we can never perceive anything other than our own beliefs, then perception can provide no external ground for any of our beliefs and we must all be crazy! I just can't agree with this doctrine of yours, I'm afraid. Particularly because it would imply that scientific investigation is based on introspective observation of our own beliefs, rather than observation of the world around us -- which seems fairly anti-scientific to me.

>But we have plenty of perfectly good physical explanations for why you might believe you're having such an experience

In fact we do not. At least, I have never seen one. Do you have a reference? In this area, people often confuse a sketch of what an explanation might look like with an actual explanation.

>and that the "experience" is really just the self-aware organization of information inside our brains, not some mystical interaction with an external entity or anything like that.

I would mostly agree with that. But I'd just point out how we currently have no physical explanation of how a self-aware organization of information could lead to a conscious experience. You are cheating a bit by introducing the term "aware', which of course could not be stated in purely physical or mathematical terms while retaining its normal connotations.

>Behaviorally speaking, both result in the same observable effects

Again, only because you irrationally (and frankly, insincerely) insist on denying that you have conscious experiences. Or admit that you have them but say I'm not allowed to consider this fact in my reasoning. I'm not sure which.

>philosophers want proof that every ludicrous possibility could not possibly be true

This is just not true. Philosophers aren't like that at all, and I don't see any great divide between scientists and philosophers over this issue. Both are taking a scientific point of view.