Sophistry. It's madness to say that the blue isn't actually there. But this is tempting for people who like the science we have, because the blue isn't there in that model of reality.
If by blue you mean--as you do--the purely subjective aspect of perceiving the color blue (call that "blue"), then it's only madness to deny it exists if you insist on confusing blue with "blue." No one but a madman would say blue doesn't exist; no philosopher should be caught saying "blue" exists.
If you can show a causal role for pure experience, that would be something else, but instead you speak of the "causal role they appear to play." But we don't want a theory where things play the role they "appear" to play; the illusion of conscious experience includes the seemingness that qualia play a causal role (Added: as I explain in my account of the related illusion of "free will."
In short, it just won't do to call qualia nihilism "madness," when you offer no arguments, only exasperation.
But modern physics is mathematical and operational, there is plenty of opportunity for something to actually be a conscious experience, while appearing in the formal theory as a state or entity with certain abstractly characterized structural and algebraic properties.
This simply doesn't solve the problem; not in the least. If you posit abstractly characterized structural entities, you are still left with the problem regarding what makes that configuration give the appearance "blue." You're also left with the problem of explaining why evolution would have provided a means of registering these "abstractly characterized structural and algebraic properties" when they make no difference for adaptation.
My guess, you espouse an epistemology that makes sense data necessary. Completely freeing epistemology from sensationalism is virtue rather than vice: philosophers have been looking for a way out of sensationalism since Karl Popper's failed falsificationism.
You need an argument better than alleging madness. Many things seem blatantly wrong before one reflects on them.
If you can show a causal role for pure experience, that would be something else, but instead you speak of the "causal role they appear to play."
I was actually talking more about the deduction that experiences are causally downstream from physical stimulation of sense organs, and causally upstream from voluntary motor action. This deduction is made because the physical brain is in that position; the physical causal sequence matches up with the subjectively conceived causal sequence "influences from outside me -> my experiences -> my...
[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.