(Reply to Shimon Edelman-2)
SE: āStevanā¦ does notā¦ defend [his] claim [that] ‘feelings are not computationsā¦ (except for the blinkered believers in the computational theory of mind).’ I argue that feelings in fact are computations, albeit not Turing computationsā¦“
In his paper, Shimon makes it clear that by “computations” he does not just mean the Turing computations referred to by the Church-Turing Thesis: “[E]very physical process instantiates a computation insofar as it progresses from state to state according to dynamics prescribed by the laws of physics, that is, by systems of differential equations.”
Hence what Shimon means by “feelings are computations” is just that they are (somehow) properties of dynamical systems (hardware) rather than just hardware-independent Turing computations (formal symbol systems).
That’s not computationalism (the metaphysical theory that felt states are [Turing] computational states); it’s physicalism (the metaphysical theory that felt states are physical [dynamical] states).
Well, yes, we’re all physicalists rather than “dualists”; but that doesn’t help solve the hard problem — of explaining how and why some physical states are felt states. This is not a metaphysical question but a functional one.
I have not yet read the “22 kiloword” Fekete & Edelman paper in detail, but I think I’ve understood enough of it to try to explain why I think it misses the mark, insofar as the hard problem is concerned:
The goal is to explain how and why we feel. The intuition (largely a visual one) is that external objects are dynamical systems, with (static and) dynamical properties (like size, shape, color) that (1) we feel because (2) they are “represented” in our brain by another system — an internal dynamical system that mirrors (and can operate on) those dynamical properties, right down to the last JND (just-noticeable-difference).
Now the Fekete & Edelman model is not yet implemented. But if ever it is, it is very possible that it might help in generating some of our capacity to do what we can do. Let’s even suppose it can generate all of it, powering a Turing robot that can do anything and everything we can do, right down to the last JND.
And we know how it does it: It has an internal dynamical system that mirrors the properties of the external dynamical systems that we can see, hear, manipulate, name and describe. That solves the “easy” problem of doing.
Now what about the feeling? If the Turing robot views a round shape, it can do with it all the things we can do with round shapes, in virtue of its internal dynamical counterparts, including the minutest of sensory discriminations (though one wonders why internal representations are needed to do same/different judgments on externally presented pairs of round shapes of identical or minutely different size). In any case, the internal analogs may come in handy for tasks such as the Shepard internal rotation task. (I say “internal” rather than “mental,” because “mental” would be a weasel-word here insofar as the question of feeling versus doing is concerned here.)
The internal representations of shape certainly mirror the shapes of the external objects, but do they mirror what it feels like to see round shapes? How? I mean, if we made a trivial toy robot that could only do same/different judgments on round shapes, or on rotated Shepard-shapes, would it be feeling anything, in virtue of its internal dynamics? Why not? Would scaling up its capacity closer and closer to ours eventually make it start feeling something? when? and how? and why?
So, no, although the idea of generating internal dynamical representations that are isomorphic to external objects is a natural intuition about how to go about building what it feels like to perceive the world into a brain or robot, all it really does is give the brain or robot a means of doing what it can do (including the minutest discrimination, all the way down to a JND). It’s an input/output isomorphism, not an input/feeling isomorphism. It is as unexplained as ever why anything should be felt at all, under any of there conditions. Why should it feel like something to discriminate? Discriminating is doing. All that’s needed is the power to do it.
And there’s also the question of commensurability: Internal and external shapes are commensurable; so are input shapes and output shapes. But what about the commensurability of external shapes and what it feels like to see them? They are commensurable only on condition that the internal analogs are indeed, somehow, felt, rather than just used to do something (like making same/different judgments for successive rotated and unrotated external shapes). But why are they felt?
So I would say that such internal analogs and their dynamics may very well cast some light on the easy problem of how the brain can do some of the things it can do, but that they leave completely untouched the hard problem of how and why it feels like something to do or be able to do what the brain can do.
SE: āthe causal role of feelingsā¦ stems from their close relationship to discernments (JNDs) and therefore to the conceptual structure of the mind“
But how and why are discernments (JNDs) felt, rather than just done?
SE: ā[Our model] avoid[s] the panpsychism implied by computational āmodelsā that are underconstrained by the intrinsic dynamics of the computational substrate“
In other words, make sure that the internal/external isomorphism is tight enough and specific enough to avoid the conclusion that “any kind of organized matter [feels] to some extent.” Agreed. But it remains to explain how and why any kind of organized matter — whether or not isomorphic up to a JND — feels to any extent at all!
SE: āWhat we offer is an attempt at a principled and tightly constrained explanatory reduction of feelings to doingsā¦ a reductive leap [to the effect that] feelings are doings in the sense that we discuss.“
Shimon, I’m afraid the reductive leap doesn’t work for me! Doings are still doings, and it’s not at all clear how or why internal analog dynamics that mirror external dynamics in the service of discriminating or any other doing should be felt dynamics rather just done dynamics.
SE: ā[C]ognitive science is a basic science ā¦ [Feeling] has the same ontological status as chargeā¦ Would you tell a physicist who offers you a theory of electrodynamics ‘Yes, I understand what electrons do with their charge, but what is charge and why do they have it?’?“
No, I wouldn’t, because it’s evident that the question-asking must stop with the four basic forces of nature (electromagnetism, gravitation, the weak force and the strong force). But feeling (unless you are a panpsychist despite the complete absence of evidence for a psychokinetic force) is not one of the basic forces of nature. And cognitive science is not a basic science!
So I’m inclined to repeat what I said in my first reply: If āBecause!ā is the only answer we can ever get to our āhardā 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 ā probably our most fundamental one. The āhardā problem may well be insoluble ā but surely that does not mean it is trivial, or a non-problem, or that it was some sort of ācategory mistakeā to have asked!