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.
Ah, no. See, I am absolutely not saying that the blue isn't there. I agree that would be madness - I've experienced blue a million times. What I'm saying is this:
During the times when your brain is in the "blue state" you also happen to be experiencing the sensation of blueness. Same goes for the sensation of pain and the brain state associated with pain. In fact, this partnership between brain-state and perception is so reliable that we're getting close to being able to record people's thoughts in video format by scanning their heads. (http://www.youtube.com/watch?v=nsjDnYxJ0bo&feature=player_embedded)
The question is, if our model allows us to predict people's sensory experiences perfectly well on the basis of purely physical phenomena, why do we need posit qualia? Seems to me that the simplest theory that describes all the data is that causal relationships between physical things are the only things that exist in this universe. If you throw out the premises that sensations aren't physical things and that physical things aren't sensations then it suddenly seems like the most natural conclusion in the world, and I've never seen any evidence that prompted me to hold onto either of those premises.
Here's a query - what did it feel like the last time you didn't have a brain state? Obviously that's a stupid question, it's impossible for you to have a brain without having it be in one state or another, and you don't have any memories from before you had a brain. Similarly, by definition you can't remember what it was like the last time you were experiencing absolutely nothing (if there was something to remember then you would have been experiencing something). So what piece of evidence was it that prompted you to hypothesise the existence of qualia?
The question is, if our model allows us to predict people's sensory experiences perfectly well on the basis of v purely physical phenomena, why do we need posit qualia?
We cant predict experienes perfectly well, because can't predict novel experiences, because we cant describe novel experiences, because we can't describe (as opposed to label) non novel experiences.
[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.