You have picked an easy case, I have picked a difficult one. If we wan't to know what the world sonars like to a bat on LSD, identity theory doens't tell us.
Well, in point of fact, I've personally never done LSD, so I don't know what color perception is like for another human on LSD, either. I could make an educated guess, though.
In case of the bat sonar, the answer is even simpler, IMO: we lack the capacity to experience what the world sonars like to a bat, except in the vaguest terms. Again, I don't see this is a problem. Bats have sonars, we don't.
Note that this is very different from saying something like "we can't know whether bats experience anything at all through their sonar", or "even if we have scanned the bat's brain, we can't predict what changes it would undergo in response to a particular sonar signal", etc. All I'm saying is, "we cannot create a sufficiently accurate mapping between our brain states and the bat's, as far as sonaring is concerned".
Again, I'm not entirely sure I understand what additional things we need to explain w.r.t qualia.
Well, in point of fact, I've personally never done LSD, so I don't know what color perception is like for another human on LSD, either. I could make an educated guess, though.
Normally I'd assume that I know what you meant and move on, but since this involves LSD... You don't know what it's like? Or you do, but it's an educated guess? What?
[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.