(Reply to Shimon Edelman)
A serious cognitive scientist ignores the rich and original work of Shimon Edelman at his peril. A master at relating perceptual differences to linguistic differences, if anyone is likely to put the “heterophenomenology” of Dan Dennett (another formidable thinker, in whatever JNDs one might differ from his views!) on a solid psychophysical and computational footing, it is Shimon.
But does the computational (or dynamical) explanation of each and every JND we can discriminate (all of which is doing) explain how or why those doings are felt?
(And if it does not, and “Because” is the only answer we can ever get to this “hard” question, does that mean it was unreasonable to have asked the question at all? I think this would be to paper over a fundamental explanatory crack — probably our most fundamental one. The “hard” problem may well be insoluble — but surely that does not mean it is trivial, or a non-problem, or that it was some sort of “category mistake” to have asked!)
SE: “Stevan is… right in denying the central… premise… that feelings are somehow distinct from and independent of doings.”
Feelings and doings seem to be tightly correlated: that’s undeniable. But it’s the causation (and causal function) that’s at issue here.
(And one can have reservations about feeling/doing commensurability too, for the psychophysical correlation is really only a doing/doing correlation: input/output. Inquiring more deeply into the “quality” of feelings, and their “resemblance” to things in the world, runs into Wittgensteinian private-language indeterminacy problems: what’s the common metric? and what’s the error-detector?)
SE: “the how part of the question is relatively easy, if one accepts that minds are what brains [and brain-like systems]… do“
Doing is what brains do. How and why they generate feelings — how and why it feels like something to do and to be able to do all that doing — is another matter.
But let me stress that the “why” in the “how and why” question is not an idle teleological query: It is a functional query, which means a causal query. If there are various functional components that generate our doing power, it seems reasonable to ask of each of them: “What causal role do they play in the successful outcome? What do they enable us to do that could not be done without them? What would be functionally missing or misfunctioning without them?”
In other words, the “why” in the “how and why” is just a call for a clear account of the specific causal contribution of feelings to the successful generation of our doing power, lest we simply take it for granted and forget that there’s a huge elephant in the room whose presence still calls for an explanation in an account of doing that looks for all the world as if it would be equally compatible with the presence or the absence of feelings.
SE: “there seems to be no… way of explaining why a… tomato feels this way… when I look at it… red [and] that way to me when I handle it… squishy… Asking why any quale [feeling] feels the way it does amounts to a category mistake… [and] deserves… only [the] answer… ‘Because’“
But the hard problem is not that of explaining how or why something feels this way rather than that way, but explaining how and why it feels like anything at all.
A category mistake is to ask whether an apple is true (“it’s not true? well then it’s false?”). There’s no category error in asking how and why we feel rather than just do.
And if the answer is just “Because,” it’s not the impatient “Because” that questions like “why is there something rather than nothing?” or even “why is there gravity?” deserve. We are squarely in the world of doing, and its functional explanation. And there is a prominent property that is undeniably present but does not seem to have any causal role (despite the fact that, ironically, it feels causal — although that’s not the reason its presence calls for an explanation).
Waving that away with “Because” and “category error” is rather too quick…
SE: “there definitely is a… way to explain why two shades of red feel this different to me… psychophysics [JNDs]“
There definitely is a way to explain how and why we can discriminate everything we can discriminate — and manipulate and categorize and name and describe.
But those are all doings and doing capacities. How and why are they felt doings and doing capacities, rather than just “done” doings and doing capacities?
(The one making the category error here seems to be Shimon!)
SE: “The conceptual leap that makes such grounding possible is akin to the explanatory move that is inherent in the… Church-Turing Thesis [CTT]…the equivalence of Turing computation… a formal concept, and effective computation… an intuitive one.”
This is a very clever analogy — between, on the one hand, “capturing” intuitive computation with Turing computation, and, on the other, “capturing” peoples’ feelings with Turing models of doing — but it unfortunately cannot do the trick:
First, the fact that Turing computation merely “captures” mathematicians’ intuitions of what they mean by computation rather than proving that they are correct is the reason CTT is a thesis and not a theorem. Mathematicians have other kinds of intuitions too — such as the Goldbach Conjecture, but those are theorems, subject to proof (such as in the recent proof of Fermat’s Last Theorem). Any thesis or conjecture can be invalidated by a single counter-example. But it takes a proof to show that it is true. The reason CTT cannot be proved true is that except when it is explicitly formalized, it is just a feeling! (Bertrand Russell, drawing on an example from William James, famously reminded mathematicians how feeling can be an unreliable guide too: “The smell of petroleum pervades throughout.”)
Now in science and engineering, we are not looking for proof of the truth of theorems but for evidence of the truth of theories. And evidence does not just mean gathering data that are compatible with and confirm the predictions of the theory. It means giving a causal explanation. This is clearest in engineering, where the way you test whether your theory successfully explains the way to get certain things done is to build a system (say, a vacuum cleaner) that tries to do those things according to the causal mechanism proposed by your theory, and show that the causal mechanism works (i.e., it can suck in dust).
Cognitive science is not basic science; it is more like reverse engineering, along lines similar to ordinary forward engineering. The only difference is that our vacuum cleaners grow on trees, so we have to try to reverse-engineer their doing-capacities and then test whether they have the causal power to generate our doings. That’s Turing’s method.
Now once we have a causal theory that is able to generate all of our doing power, we have causally explained doing (the “easy” problem). But have we “captured” feeling, the way the CTT has provisionally “captured” mathematicians’ intuitions about what computation is?
The answer is already apparent with CTT — which is, in a sense, also a cognitive theory of computation: a theory not only of what computation is, but of how computation is implemented in the brain. Computation, however, is doing, not feeling! So although mathematicians may have feelings about computation — just as we have feelings about tomatoes — it is not feelings that Turing computation implements but computations (doings). And (except for the blinkered believers in the computational theory of mind), feelings are not computations.
So the only sense in which a successful Turing theory of doing “captures” feeling is that it generates (and explains, causally) the doings that are correlated with feeling. It does not explain how or why those doings are felt or depend causally on feeling. The “conceptual leap” — to the conclusion that the successful explanation of doing explains feeling — is just as wrong in the case of Turing robotics as the notion that Turing computation (CTT) has explained mathematicians’ feelings about what computation is. Turing computation (provisionally) captures what mathematicians are doing when they compute. There has not yet been a counterexample; maybe there never will be. That is unproven. Explaining how/why it feels like something for mathematicians to compute — and how/why it feels like something for mathematicians to think about computation and about what is and is not computation — is a gap not bridged by the “conceptual leap.”
SE: “Just like the CTT,… equating… feelings with discriminations (doings) cannot be proved… [but] many explanatory benefits may ensue (including the demystification of meanings).“
Many explanatory benefits ensue from explaining doing (i.e., solving the “easy problem”); that is uncontested. Shimon’s work especially will help integrate perceptual capacity with linguistic capacity. But that’s all on the doing side of the ledger.
SE: “ Towards a computational theory of experience… equates… feeling – with the dynamically unfolding trajectory that the collective state of the… brain – its doing — traces through an intrinsically structured space of possible trajectories (which defines the range of [differences]… the mind… can [feel].“
This may define the range of differences that the brain can discriminate (do). But the fact that it’s felt alas remains untouched.