Once we understand all the physical facts (including e.g. the physical causes of people talking about qualia) there are no other facts to understand.
How do you know? If materialism is a scientific hypothesis, it is disproveable, ie it could run into a phenomenon it cannot explain. OTOH, if it is a case of dogmatically rejecting anythign that doens't fit a materialistic worldview, how is that rational?
If materialism is a scientific hypothesis, it is disproveable, ie it could run into a phenomenon it cannot explain.
I could imagine such a thing happening. The fact that it hasn't happened is why we should be firm materialists. As it stands, we have every reason to expect that when we delve into the neurobiology of the brain, we will find a complete, material, physical explanation for the phenomenon of "people talking about qualia." Yes, there's "still a chance" that consciousness may turn out to somehow lie outside the realm of physics as we know it, but that doesn't license you to believe or expect it.
[Cross-posted.]
1. Defining the problem: The inverted spectrum
A. Attempted solutions to the inverted spectrum.
B. The “substitution bias” of solving the “easy problem of consciousness” instead of the “hard problem.”
2. The false intuition of direct awareness
A. Our sense that the existence of raw experience is self-evident doesn’t show that it is true.
B. Experience can’t reveal the error in the intuition that raw experience exists.
C. We can’t capture the ineffable core of raw experience with language because there’s really nothing there.
D. We believe raw experience exists without detecting it.
3. The conceptual economy of qualia nihilism pays off in philosophical progress
4. Relying on the brute force of an intuition is rationally specious.
Against these considerations, the only argument for retaining raw experience in our ontology is the sheer strength of everyone’s belief in its existence. How much weight should we attach to a strong belief whose validity we can't check? None. Beliefs ordinarily earn a presumption of truth from the absence of empirical challenge, but when empirical challenge is impossible in principle, the belief deserves no confidence.