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.
Theres a difference between causation and reduction. The idea that qualia have physical causes is compatible with dualism, the idea that they are not ieducible to physics.
Knowing what causes non standard qualia, or where they diverge, still doesn't tell you how non standard qualia feel to the person having them.
For that reason, we are not going to have private language dictionaries any time soon. Looking at brain scans of someone with non standard qualia us not going to tell me what their qualia are as qualia.
Granted; we won't have definitive evidence for or against dualism until we're at the point that we can fully test the (non-) reductive nature of qualia. If people who have access to each other's private language dictionaries still report meta-feeling that the other person feels different qualia from the same mental stimulus then I'll have more evidence for dualism than I do now. True, that won't help with incomparable qualia, but it would be kind of...convenient...if the only incomparable qualia are the ones that people report feeling differently.