A lot of philosophers seem to take the higher-order thought theory of consciousness to be eliminative or deflationary about consciousness; of course, it doesn’t help that people go around saying that we need to get rid of qualia or even that we should endorse the claim that we ourselves are zombies! But aside from this misguided rhetoric I just don’t see any argument which shows that the higher-order theory is eliminative or deflationary. Of course I do not deny that it is counter-intuitive but so is any cutting edge theory. Let us rehearse what I take to be the basic argument for the higher-order theory.
1. A mental state that I am in no way aware of myself as being in is not a conscious mental state
This seems to me to be a common sense platitude and maybe even an analytic truth. If one accepts this then some kind of higher-order theory of consciousness is true: (1) is the converse of the transitivity principle.
2. Certain kinds of thoughts can make us aware of things.
Thoughts that are seemingly unmediated by inference and represent the target as present make us aware of the target. if this isn’t true then higher-order thought theory is false, though some other kind of higher-order theory may still be true.
3. Phenomenal feel is a matter of what it is like for one to have conscious mental states
This also seems like a common sense platitude. If one accepts this then explaining phenomenal consciousness is just explaining what it is like for one to have conscious mental states.
4. What it is like for one to have a conscious mental state is determined by a higher-order thought
This is supported or at least made plausible by considerations about wine tasting and the like. In the wine tasting case one’s experience changes as one learns a new concept. It is consistent with this that applying a concept to one’s first-order states results in a change in phenomenal experience with no change in the first-order state’s properties (this is not the only thing this is consistent with of course). If this is right (and it is presumably empirically testable) then applying new concepts results in a change in what it is like for one to have the experience. If this is right then perhaps it is not too crazy to think that applying concepts is what results in phenomenal feel in the first place.
5. Only conscious mental states exhibit phenomenal feel
This is where the higher-order theory stands or falls. If it really is the case that there are no phenomenal feels when a state is unconscious then we really would have evidence that higher-order thoughts result in or produce phenomenal consciousness. It is not clear that this is true but it can be supported by philosophical analysis. For instance it is not at all clear that anything substantive hangs on whether we call qualitative properties of which we are in no way aware phenomenally conscious or not. if all one means is that unconscious pains have some property in virtue of which they are pains and that when we are aware of ourselves as being in feels a certain way then there is no disagreement. if on the other hand, one means that the unconscious pain feel painful for the person that has it then it is not clear what that would even mean. Besides this there are no telling empirical reasons to think that it is wrong.
Now each one of these claims is more or less controversial but if one accepts them then one accepts the higher-order thought theory and it seems to me that nothing in these four claims rules out qualia realism. In fact it seems that if these five claims are true then we have succeeded in explaining what phenomenal consciousness is and if we ultimately identify the neural means by which all of this is implemented then we will have discovered that consciousness is physical.
As of right now it seems like we can conceive of creatures that have HOTs but which lack phenomenal feels but further empirical results may yet show that the HOT theory is the best theory of consciousness available (or if you prefer: it may show that it is true). The acknowledgement that it seems conceivable to have HOTs without phenomenal feel is enough to get qualia realism but not enough to show that higher-order thought theory is false. Is it really so strange that we should find out that qualia just are higher-order thoughts and that higher-order thoughts just are brain states? Sure, it is surprising; but is it more surprising than relativity theory, quantum mechanics, or string theory? I should think that the discovery of the relativity of simultaneity, Bose-Einstein condensates, dimensionless point-particles, and 11 dimensional space-time are quite a bit surprising indeed!