AT: 1. If we ask how/why some functions are felt, we seem to grant that some functions are not felt, and we can ask if there is a systematic biophysical  difference between felt functions and unfelt functions. 

We had better grant that some functions are felt and some are not felt (since it's true!): My toothache is felt; my thermoregulation is not (although I can feel hot); a furnace's thermoregulation is unfelt, and the furnace does not feel hot (or anything).


We can certainly look for biophysical differences between my felt and unfelt functions; but just as the functional correlates of my feelings will not tell you how or why I feel, the functional correlates of felt and unfelt functions won't tell you either. (And the reason is that there simply isn't the causal room for feelings to have any effects at all (independent of their correlated functions), hence there isn't any room for a causal explanation of how and why we feel: the correlated functions tell all there is to tell.

AT: 2. We can also ask why any felt function is felt. -- It seems to me that question 2 is equivalent to asking why anything like feeling (consciousness) exists at all. Would you agree, Stevan?

Yes, which is why I've reformulated the mind/body problem as the feeling/function problem: How and why are some functions felt?

About the "how" -- i.e., how are feelings generated? -- I don't doubt for a minute that the cause is the brain. What I doubt is that we can explain how the brain generates the feelings, rather than just the correlated functions. So this is not about whether materialism is true. (Of course it is.) It is about whether material (functional) explanation is complete: No it isn't. There's an explanatory gap, insofar as the (fact of) feeling is concerned.

But the harder question is the "why." The "why" is not teleological, it is functional, and causal: In a sense, the only satisfactory answer to a functional question -- why does this device work this way? what functional role does property X play? -- is a functional answer. But if we ask a functional question about feeling -- why does this device feel? what functional role does the fact that it feels play? -- we draw a blank, because feelings have no independent functional role. All the functionality is accounted for by the functional correlates of feelings! That's why "Why are some functions felt rather than just functed?" is the core question. And since a satisfying answer could only be a causal/functional one -- and there is simply no causal room for such an answer (given that telekinetic dualism is false), we are stuck with an explanatory gap.
 
(I should have added in my earlier reply, Arnold, that the object is not to predict what we feel, but to explain that we feel (how, why). And that will not be accomplished by analogs, representations, etc.)

-- SH