Explaining the Mind: Problems, Problems
by Stevan Harnad
The Feeling of What Happens
by Antonio R. Damasio
Harcourt Brace, 2000
hardcover, $TKTK; softcover, $15.00
A Universe of Consciousness
by Gerald M. Edelman and Giulio Tononi
hardcover, $TKTK; softcover, $17.00
The Mysterious Flame
by Colin McGinn
Basic Books, 1999
hardcover, $TKTK; softcover, $TKTK
The Cultural Origins of Human Cognition
by Michael Tomasello
Harvard University Press, 1999
hardcover, $TKTK; softcover, $TKTK
The Mind Doesn't Work that Way
by Jerry A. Fodor
MIT Press, 2000
Three of the books under review are about consciousness, one is about meaning, and one is about language, but the topics are inter-related, as we shall see. The reader may find it surprising to learn that Iit has lately become fashionable in cognitive science to call the problem of consciousness the "hard problem," and the problems of meaning and language (and brain function and behavior) the "easy problems." of cognitive scienceEverything is relative. The "easy problems" may be easier, compared to than the "hard oneproblem," but that does not make them any easier than most other scientific problems.
THE HARD PROBLEM
What, then, is the "hard problem?one," then?It's as old as the human mind itself, and it's probably lurking behind our people's ideas about religion, and the immateriality and immortality of the soul,. and Iit has been pondered
since the advent of Pphilosophy, where it is usually called the "mind-/body" problem. Unfortunately, the word "mind" is ambiguous here,in that context, and "body" is a misnomer. Some philosophers think it's more useful to call it instead the "mental/-physical" problem, instead, but even that doesn't quite do the trick.
The problem itself is in arises in trying to relate ing one sort kind of "thing" (mental things) with another sort kind of thing (physical things). We Everyone knows that physical things are encompass more than not just "bodies": They are made up of matter and energy, the stuff that physicists (and chemists and biologists and engineers) study and account for explain to us with their usual familiar functional, cause/-and-effect explanations: the eye works by focusing light on the retina; the lake warmed up because the sun was shining. And we everyone knows exactly what mental "things" are, too: They are what is going on in our heads when we are awake: thoughts, experiences, feelings.
The problem is: How is one to do we put those two kinds of things together: Are they both the same kind of thing? Are thoughts,/ experiences/ and
feelings just matter/ and energy, somehow? If so, How? (And here I pause to let the reader test whether, mirabile dictu, he can provide a satisfactory answer to this hard question where everyone else so far has failed). . . .)
vs. Decorative Epiphenomenalism
If the mental and the physical they are not the same kind of thing, what is the relation between the mental and the physicalthem? It is clear that We know they are exactly correlated, but correlation that is not an explanation. How does the mental fit into the physical world causally? Is it an extra "force," like gravitation? Some people, Those who have taken the path of embrace the supernatural in the face of the hard problem, reply "yes," and boldly proclaim the "telekinetic" power of the mind (rather like Uri Geller's spoon-bending, except that the process they are describing would be it's telekineticsis even when if one's fingers, unlike Geller's, were strong enough to we bend the spoon with our fingers: according to telekinetic theory, one We moves our
one's fingers--and the fingers then do whatever they do-- because we one feels like it).
But Tthe trouble with this such an easy solution to the hard problem is that it has some uneasy consequences: It is at odds with the laws of matter/energy conservation laws of mass and energy, Physics, causal laws of physics that have an awful lot mountains of evidence in their favor.supporting them, all over the universe. To see regard the mental as a telekinetic force, we one have has to be ready to believe, for instance, that some rather remarkable things are going on on our small planet: Tthings move because they are willed to move, not just because of the usual transfer of energy. And what is the source of theis telekinetic force? That's anyone's guess, but it can't be just our the brains, because our the brains, like our the hearts and our the livers, are is just that ordinary stuff:, matter and /energy, structure and /function. (If our the brains were turns out to be the cause of all people's our motions after all--in other words, i.e., if there were no telekinesis really doesn't happen, as I suspect most readers of The Sciences would be willing to grant--, then it would never be true that one we moves because one
we feels like it; it would just feel-like that was how and /why one was we were moving.)
I will not pursue the telekinetic option any further (it is often called "dualism"), because, in exchange for "solving" the hard problem, it seems to raise even harder problems, pitting itself against all the rest of science. Suffice it to say that none of the authors of the books under review would endorse telekinetic dualism. They are all committed to explanations that stay within the natural bounds of matter and energy, structure and function--bounds set by current theory and evidence in physics, biology and engineering. Yet one must let us admit that telekinesis certainly feels like the right explanation for our the minds, and what they the mind does, and how. It's just that it's such an explanation that unfortunately does not fit with the scientific explanation of everyanything else--and hence so the exceptional character of the explanation would itself would stand in need of scientific explanation.
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Three of the books under review try to take on the hard problem directly:. Antonio Damasio is convinced that does it using recent advances in understanding brain anatomy, and physiology and neurology can offer new perspectives on the problem.; Gerald Edelman &and Giulio Tononi are equally sanguine about the insights gained from use computational models ing of brain function. Colin McGinn, in contrast, does not try to solve the hard problem at all, but with an excuse: Hhe argues that, although the problem does have a solution, the human brain could neither is incapable of find it ing nor understand ing it if such a solution miraculously came to be formulated.
Two Ways to Beg the Hard QuestionThe other two books under review, The books by Michael Tomasello and by Jerry Fodor, and by Tomasellodeal with language and meaning, respectively, topics so closely related to the problem of consciousness that its discussion would seem essential. Yet neither author do not ventures to take on the hard problem. at all. Tomasello does not even mention consciousness. And Fodor thinks it would be futile
to discuss it, but, (unlike McGinn), he does not say why (he spends his time instead trying to show why we science may not even be able to solve some of the easy problems!). And Tomasello does not even mention consciousness. In the end, though, even But Damasio and Edelman &and Tononi make no headway in answering explicitly state that they will not beg the hard question,. because they beg it.
There are basically two ways to beg the question. One way is to change the subject, swap an easy problem for the hard one (but keep calling it the hard one anyway), and then solve that the easy problem instead. The other second way is simply to provide an easy but covertly inadequate solution, but then interpret it as if it had solved the hard problem. Damasio does pursues the first gambit; and Edelman &and Tononi do adopt the second.
Damasio announces that he will not beg the question. hHe is not merely going to explain intelligence, or language, or brain function or behavior, because any one of them for all of those could in principle be explained in principle even if without there being any were no hard problem at all.: And in fact, that point is an important distinction to make: If people we had their very
same familiar intellectual and linguistic capacities we have, but we were not conscious (no mental states, no thoughts, experiences, or feelings), then there would still be the "easy" problem of explaining our those capacities in terms of our brain function., bBut addressing that problem would just be ordinary ("easy") science. Let us I shall call that kind of an explanation a structural-/functional explanation, or "functional" explanation (shorthand for short.a structural-/functional explanation). Functional explanations are perfectly compatible with the matter/ and energy explanations of given by physics, biology and engineering.
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What makes the hard problem hard is that that giving functional explanations for mental states is not all there is to it: We People are not just Zombiezombies with certain intellectual and linguistic capacities. We are conscious beings, that is, we do have mental states: thoughts,
experiences, feelings. Let's call wWhatever it is that makes mental such states mental I shall call "feelings.," for short. [[Thus Iif we were nonfeeling Zombiezombies, there would be no hard problem.]] What makes the hard problem hard is precisely the mysterious difficulty of explaining feelings functionally. So the "mind/-body" problem is actually the "feeling/-function" problem.
Why is it so difficult hard (if not impossible) to explain feelings in terms of function? The reason is that Because a functional explanation is always a cause/-and-effect explanation, showing how/ or why something works the way it does. A functional explanation is fine for ordinary, nonfeeling matter/ and energy[[: the stuff investigated by physics, biology, and engineering]]. But every time we one tryies to explain a feeling functionally, we find it turns out that the structure/functional explanation alone can do the cause/-and-effect job just fine [[(thank you very much!)]], and the feeling just falls by the wayside, unexplained.
Here is an example:Thus Aa functional explanation of "pain" might go something like this: Pain is a signal that indicates that tissue has
been injured. It is useful for an organism's survival and reproduction to minimize tissue injury, to learn and remember to avoid what has caused injury in the past, to avoid contact between a currently injured body- part and other objects while the part is still damaged, etc.and so forth. The workings of the sensorimotor and neural machinery for accomplishing all this, including the computational mechanism that would do the learning, the remembering, the selective attendtiong, and so forthetc., could all be described, tested, confirmed, and fully understood. Part of that system for avoiding tissue damage is a signal that tissue has been injured: pain. And that signal, too, could, in principle, be functionally and structurally described. The only part that would remain unexplained is why pain feels like something: The functional explanation accounts for the functional facts, but the feeling is left out. And so it goes: Eevery time you try to give a functional explanation of feeling, the feeling itself turns out to be functionally superfluous (unless you happen to be except for a telekinetic dualists!).
In short, we know that we are not nonfeeling
less Zombiezombies. The hard problem is explaining how and why we are not. And because For how's/ and why's are purely functional matters, that would . That seems to leave only two possible ilitiesways to characterize feelings: (1) that feelings they are merely "decorative" albeit notn functional epiphenomena, but merely "decorative," piggy-backing (for some inexplicable[[, because nonfunctional,]] reason) on certain biological functions; or (2) that feelings operate are telekinetically (the position of the dualistsm). The hard problem is finding an explanation for feelings that is neither (1) nor (2). My own view is that this is simply impossible. How do our the authors of the five books approach the issuefare with this?
Motions, Emotions, and Unfelt Feelings
Damasio sets out determined not to beg the hard question. Even his title, The Feeling of What Happens, makes it clear that what he wants to take on it is the problem of feeling, that he wants to take on directly, not something else.: "The Feeling
of What Happens: Body and Emotion in the Making of Consciousness." And Hhis book does provides a great deal of new, insightful and illuminating data and theory about the brain areas of the brain correlated with feeling, especially particularly the feeling of the "self," and about the remarkable ways in which they those areas can diminishatrophy or break down in states such as sleep, coma, vegetative state, epileptic automatism and akinetic mutism, the most primitive feeling-state of motionless muteness. We are all Everyone is a Zombiezombies when we are in deep, dreamless sleep; are we Zombiezombies in any of theose more active states, too? These Such questions and answers are fascinating, and the correlates between brain states and behavior are This is of great interest to the clinician, trying to do diagnosis, prognosis and treatment. It is also useful to the victim of brain injury, patients, patients' the families of such patients, and to everyanyone else interested in how their the workings of own the brain.but they do not include the hard one. But theose are all the "easy" problems. Do Damasio's findings cast shed any light on the hard problem of how/ and why we
feel at all?
Alas, they do not, and I think I can pinpoint exactly where the question gets begged: Damasio is intent on providing a bottom-up explanation of feelings, from the most primitive feeling-state of motionless muteness (akinetic mutism) to feeling-states of the very highest- order. feeling-states of a philosopher like Descartes when he is reflecting on the nature of mind. But explaining the variations along this such a hierarchy of feeling states is the easy part; the hard part is explaining how and why/ how any of it is felt at all. The critical transition, in other words, is between nonfeeling and feeling, and thatis is the transition that Damasio completely overlooks.
Instead, Damasio he rests his hierarchy of feeling-states on a very highly nonstandard (and, I think, in the end, incoherent) notion concept of "emotion." On the face of it, an "emotion" is just a synonym for a certain kind of feeling. (Other kinds of feelings would be include sensations, like such as seeing something blue or hearing something loud;, hybrid emotion/-sensations, like such as feeling
pain;, desire- states, like such as wanting something;, psychomotor states, like such as willing an action;, or and complex feeling/-knowing- states, like such as believing, doubting, or understanding something.) But Damasio uses applies the concept of emotion in an equivocal way, in an attempt so as to bridge the unbridgeable gap between nonfeeling and feeling. For Hhis bottom-level "emotions" (readers can confirm this for themselves) are either just motions, or in other words (movement tendencies and their underlying brain activities), in which case they are no kind of feeling at all., and leave us as clueless as before about how to bridge the gap, oOr, worse, they emotions are "unfelt feelings," which is a contradiction in terms. Either way, one is left just as clueless as before about how to bridge the gap between nonfeeling and feeling. Yet it is only by invoking using this such a blurred notion concept of emotion that Damasio gives the (illusory) impression of having made some sort of a successful transition from the unfelt to the felt.
Descartes (whom some people wrongly blame for the idea of dualism) was the subject of an earlier
book of Damasio's, titled prior book, "Descartes' Error." In that book According to Damasio argued that, Descartes had made the mistakenly of trying tried to separate what in the brain is inseparable: the psychic (mind) and the somatic (body). In the functional anatomy of the brain, Damasio went on, functional anatomy, there is no such separation. I agree; Bbut I must hasten to add that Damasio's point is irrelevant to refuting Descartes: let us not forget that after all, all of the brain, both structure and function, is "somatic."--that is, explained entirely by ordinary physical matter and energy. And that's precisely the same error Damasio's makes in The Feeling of What Happens, error in focusing on the functional aspects of with motions and emotions. For the functional part of emotion, the somatic part, is indeed, as Damasio maintains, just motion! But the felt, (or psychic,) part is something else:, something 100 percent% correlated with brain structure and function, to be sure, --but, again, correlation isn't explanation. Correlations need a causal explanation, and the only candidate explanation, namely (telekinetic dualism,) is a nonstarter. Hard Tough luck.
Edelman &and Tononi's Hermeneutics
So Damasio has unfortunately begged the hard question with his motion/emotions and his unfelt feelings. Do Like Damasio, Edelman &and Tononi set out in their book promising not to beg the hard question. Do they manage to do fare any better? They too set out promising not to beg the hard question the way others have done before them. They want are at pains to make sure they explain the difference between real seeing, and, say, the activity of an optical transducer (e.g., such as a photo-cell). It will not do, as they correctly point out, simply to declare that one's favorite functional mechanism "feels" any more than it will do simply to declare that an optical transducer "sees." In both cases Tthe how/ and why of the feeling itself must also be explained. in both cases.
But then Edelman &and Tononi go ahead and beg the hard, "feeling" question anyway. They describe some very interesting intriguing functional networks--"distributed, re-entrant ones"--which they hypothesize suggest could to have some
powerful functional capacities (some of them already experimentally demonstrated, experimentally, many of them not yet). They also describe how thesesuch networks are brainlike in many ways. Thatis is all very important and exciting stuff, but it is still all just functional.: The nagging question still remains: How/ and why do the feelings come in (other than as the usual mysterious, unexplicated correlations)? [[For Without an answer to that question, Edelman and Tononi's discussion otherwise this is just an exercise in hermeneutics: interpreting a the functional mechanism that correlates with a feeling is interpreted as actually being the feeling itself, and thereby being the functional explanation of the feeling; whereas in reality it is merely the explanation of the functions that are mysteriously correlated with the feeling, nothing more.]]
We can pinpoint Tthe locus of the question-begging can be pinpointed here, too: Edelman &and Tononi's network model is largely a category-learning mechanism for learning categories. An essential part of that mechanism is the need for discrimination. And their treatment of
discrimination is equivocal in just the way counterpart of Damasio's equivocation treatment of on motions/emotions is. their treatment of "discrimination."
To discriminate is to be able to tell things apart. Psychophysicists speak about the "jnd"JND, or "just-noticeable-difference"--the smallest sensory difference that we people can feel. Feel? But of course psychophysics, being an ordinary functional science like all the others, really only deals with the smallest sensory difference we people can detect and respond to. That could just as well apply to an optical transducer. The fact that it also happens to feel-like something when one to detects those differences is another matter, and Edelman &and Tononi's model comes no closer to explaining the how/ and why of that than an optical transducer does.
[[Two other points are worth making in passing about Edelman &and Tononi: (1) They cast some of their argument in terms of another fashionable problem, the so-called "Bbinding Pproblem": ("How does the brain manage to '"bind"' all the its simultaneous sensations it receives while perceiving of an object into one unitary percept of
that object?"). But would there be a Bbinding Pproblem at all if there were nothing it felt-like to perceive an object--if our the brains just went about doing all their its functional business of moving, categorizing, discriminating without feeling anything while doing it? Might the "Bbinding Pproblem" be just another variant of the (hard) question of how/ and why we people are not Zombiezombies? (2) I personally did not glean much insight from Edelman and Tononi'sthe authors' paraphilosophical koan, "Bbeing Pprecedes Ddescribing."]]
McGinn: We Don't Have the Brains
Philosopher Colin McGinn suggests that the reason our species must resort to question-begging or koans in the face of the hard problem is that peoplewe just don't have the brains to solve it. Now I will let us immediately concede that he could be right about that--but by the same token, the Ccreationists could be right, too. There may be mysteries beyond the grasp of our intellects.
But why should the feeling/-function problem be one of them? To make McGinn's suggestion this
into anything more than an arbitrary conjecture, one would have to answer a how/-and-why question every bit as hard as the hard problem itself, namely, how/ and why is the human brain unable to solve the hard problem? McGinn unfortunately provides no hint of an answer to that question,about this, leaving us the reader not one whit less mystified than he was before he McGinn asserted informed us that the our mystification was is innate. That's about as unhelpful as informing us that the brain does cause feelings somehow, but not explaining how/why.
What is interesting about For surely the latter is true: The brain does somehow cause feelings; no nondualist doubts that. But the hard problem is explaining how/why. Now McGinn's position is interesting in the sense that he is his declaring, [[positively (thoughbut nondemonstratively)]], declaration that there is an answer,reason the brain causes feelings but it (the reason just happens to be one that one we people are not equipped to grasp). By way of As evidence, he gives examples of other kinds of things--things whose existence is hardly in question--that our the brains are is not equipped
to grasp either.: People We canno't know, for instance, what it feels like to be a bat (with its extra sonar sense), any more than someone born blind can know what it feels like to see. But thatis' is cheating! It is like tantamount to saying that there is a feeling is simply missing from our the human repertoire, and that feeling is: what it feels like to know.
The Solution to the Feeling/function Problem!At the very least, Tto give that his point some substance, McGinn would have to state say what the solution to the hard problem, as well as was how and why it is the solution, even though it does not feel like the solution. He would also have to say how and why people are unable to that we were incapable of grasping the solution as being the solution.--and how and why it is the solution even though it does not feel like the solution. But, one might ask, why should the solution have such a bizarre set of properties? For, oOn the face of it, all that is required we are asking for is a functional, explanation, a how/-and-why explanation of conscious feeling. Such explanations tend to be objective ones, which do not depending on how they "feel" to you, any more than the truth
of a mathematical proof depends on whether or not it feels true to you. If there is indeed a functional explanation of feeling, it ought to be possible to at least to state it (and test it, functionally), even if, because of the our brain's limitations, such a statement would it will not be sufficient to dispel the attendant mystery about the hard problem from our minds.
But perhaps McGinn means something even stronger than this: Not just that we human beings lack the sense to see that something is a solution to the hard problem even when it is staring us in the face, but that we even lack the means to state that such a solution. But that would be very odd, because it would be a limit not just on the nature of our the brains, but on the expressive power of language and mathematics (both of which, though rooted in our the brains, have universal, brain-independent powers, too): I may not be able to feel what it is like to be a bat, but surely I should be able to state all the functional facts about it (in fact, that's exactly how we understand the bat's sonar sense is understood, and there is absolutely no mystery there, just the bat'sa feeling that we know that we lack).
No, I don't think McGinn's conjecture helps us with the hard question at all: If the question is, how/ and why do we feel, then his reply that we are not equipped to know how/why simply raises another question, just as hard: How/ and why not?
Before leaving the hard problem and moving on to the two books that address easier problems, I will venture an answer: It is not because we have the wrong brains. It's because of the nature of functional explanation and the nature of feeling. The only alternative to telekinesis (in which feelings would have an independent causal power of their own) is that feelings do not have an independent causal power of their own. They just are. (We know Ttheiry existence; that'is not in dispute.) Moreover, they pose no problem to the rest of science if they are simply side-effects of matter/ and energy,/ structure/ and function, not causes in their own right.
Make no mistake: no one is the We are no less mystified by this the conclusion that the "function" of feelings is merely decorative "function" for feelings (a position called "epiphenomenalism"), but at least it moots any further how/-and-why questions. And iIt implies
that the hard problem is insoluble,: that Ttelekinesis itself is false, and that. Ffeeling has no is immune to (nontelekinetic) functional explanation (hence it is inexplicable). [[And we are one is still left with the sense of mystery about how and why this should be so--a mystery that could perhaps only be dispelled if we did have an extra sense, a telepathic sense, of the way matter/-energy/-structure/-function causes feeling.]] [[But that hypothetical sense is just as self-contradictory, hence impossible, as a functional explanation of feeling, because of the essentially first-person nature of feeling: The only feelings you can feel are your own. ("I feel your pain" is just a metaphor.) So any "telepathic" sense I had of how nonfeeling causes feeling could only be an illusion. I can feel only what I feel, not how I (or anyone else) feel(s).]]
Tomasello: Pantomime vs. Propositions
The question Tomasello is trying to answer is unapologetically one of the "easy" ones: How and why does our species, and no other, master language? In the past, other theorists have begged
the question of consciousness by suggesting that having consciousness and having language are somehow one and the same thing, but Tomasello will have no part of that view. He recognizes that animals--particularly nonhuman primates and other mammals-- not only have feelings but that they are also very smart.; sSo in many ways the question about language is: How and why do we people differ from other animals in thatis respect? What is the functional specialization that makes people us capable of language, and them other animals incapable?
To answer thatis question, Tomasello studies the behavioral, social, conceptual and communicative capacities of (1) apes as well as those of (2) children, further charting them in children both before (2a) and after (2b) the age at which they acquire acquisition of language. His comparative studies point to a few critical capacities: the capacity to imitate others,; the capacity to "mind-read," or in other words, (i.e., to sense what others are seeing, wanting, or thinking;), and the capacity to monitor and coordinate joint attention with others: (to sense that both of you are looking at or thinking about
the same thing, and to sense that the other one senses that too.: (Damasio's mechanisms for the sense of self would come in very handy here). No nonhuman species has thatis set of capacities in full, and not even the human child does until the onset of age when language. usually begins. So Tomasello concludes that they precisely those capacities are make up the functional basis of language.
These findings are very important, and, as Tomasello shows, the capacities he has isolated form a basis for human culture. But do they? explain language? (For the moment, I will leave aside There is still the separate question of the functional basis of grammatical capacity-- (another "easy" problem.), but let us leave that aside, as a functionally autonomous module, until we get to Fodor's book. Apart from grammar, do we really have the functional basis for language here? I would like to suggest that we they do not. For Hhuman language is, among other things, the capacity to express any proposition with a string of symbols-- (e.g., "The cat is on the mat," "Feeling cannot be explained functionally," "2 +plus 2 =is 4"--) plus the capacity to understand symbol strings as
But if you look closely at the capacities Tomasello has singled out (and even if you design a functional model that will actually implements those capacities), you will find that you have a mechanism that is capable of producing and sharing social pantomime.: Such a mechanism could aActing out present and future scenes, drawing people's attention to this or that, shareing all the kinds of knowledge that can be shared by this sort kind of joint activity--but it could not doesn't provide a clue about how to get from pantomime to propositions. Even acting out the cat's being on the mat is simply that: a pantomime of the cat being on the mat, in much the same way that the actuality of the cat's actually being on the mat is the same pantomime.that too.
In short, entities with Tomasello's functional capacities remain But so far we are still in the analog world of events, and copies and re-enactments of those events. Such capacities This may well be a necessary preconditions for language. But there it is not language proper until onewe makes the transition from theis analog world of social imitation, to the arbitrary, symbolic world
[[Perhaps Tomasello's functional resources need to be augmented with Edelman &and Tononi's: If their category- learning network has the power they say it has, it should be able to learn to detect and identify cats and mats and "on-ness." So far that just names them. But iIf it can also string those names concepts into propositions that describe events and can be construed as either true or false, then we may indeed be closer to the functional substrate for language capacity may indeed be at hand.]]
Fodor's Skepticism about Explaining the Mind
Building propositions out of imitation or even category-learning,This, however, is an enterprise about which our last author, Jerry Fodor, is somewhat skeptical. To understand what Fodor is driving at, you have to know where he is coming from. Fodor, like McGinn, is a philosopher (in fact they are now both at Rutgers University in New Brunswick, New Jersey), but his work is in part inspired by the monumental grammatical work of the linguist Noam Chomsky of MITon grammar. Chomsky
showed that much of the human a lot of our grammatical capacity for grammar, rather than being learned, arises from a complex inborn structure in our the brains., Furthermore, and that that inborn structure (U"universal Ggrammar,": or UG,) probably did not evolve the usual way, the way that fins or wings did: instead, UG is somehow an intrinsic part of the structure of matter, ever since the Big-Bang, or possibly even a necessary part of the eternal Platonic world of logic and mathematics, constraining matter whenever it is configured into a mechanism capable of language.
Now this view of Chomsky's is highly controversial, but it has a great deal of evidence supporting it: It does look as if UG isn't and cannot be learned by the language-learning child (as Chomsky has long pointed out, the trial- and- error possibilities are far too large, and the child's actual learning time and experience far too small); for similar reasons, it is hard to imagine how UG could have evolved in the usual way (but thisat conclusion is perhaps not as firmly based on evidence as the fact that itUG cannot have been learned in childhood).
Fodor, impressed by the innateness of one
function of the mind, UG, generalizes it to other functions that go far beyond the evidence for UG: Fodor thinks that most categories ("cat," "mat," "object," number," and so forthetc.) are innate and unlearned too, just as UG is. All that children we learn is what names to call them; their meanings are already innately in our their heads, like place-holders merely waiting for labels. If this assertion is true, it is bad news for Edelman &and Tononi's category-learning networks, because it leaves them very precious little to do: Most of the category structure of the world would somehow have to be built into them in advance.
But is there any reason to believe it Fodor's assertion is true? Is there any evidence that there are not examples enough, andor time, for children (and adults) to learn all the kinds of things there are in the concrete and abstract world by trial and error, guided by feedback indicating when they get it right and wrong? I think there is no such evidence. But then why does Fodor believe that what is true of grammar might be true of meaning too?
I think the answer is related to yet another ("easy") problem, Tthe symbol-grounding problem: Symbols alone do not mean anything. Ignorant of
Chinese, you would look in vain for the meaning of any Chinese word in a Chinese/-Chinese dictionary: It's all in there, and yet it isn't! You look up a definition, and it's just more meaningless symbols, even though, for a Chinese speaker who does not know the meaning of that particular word, but does know the meaning of the words used to define it, it's enough to convey the new meaning.
The example illustrates at once is is at the same time the power and the limitation of language: In principle, you can find out anything and everything from strings of words expressing propositions, but you can't start from scratch: Some of the words have to be "grounded" in something other than just more (meaningless) words. How are those basic words to be grounded? Edelman &and Tononi's networks, linked to the world through sensors and effectors, sound like a good start, although onewe would be do well-advised to build in the functions Damasio describes for internal sensorimotor maps and the self, as well as the functions Tomasello describes for social communication.
Such a system would then ground some of its symbols directly, in the capacity to detect,
discriminate, categorize and manipulate the things they stand for in the outside world. Other symbols it could then be grounded indirectly, through propositions that define them in terms of already grounded symbols.
Fodor thinks thatis sort kind of mechanism is a nonstarter, for pretty much the same reason that the "associationism" of 17seventeenth- century philosophers was a nonstarter: Thought and meaning arise is not merely through the "association" of "ideas." Thought has structure over and above mere association in time and space. (So Fodor would not believe in the Edelman & Tononi network module of such a hybrid symbol-grounding system.) Symbols and computation can perhaps capture some of the structure of thought, but Fodor, although he is a functionalist and a computationalist (computation is his "language of thought"), doubts that they computation can do the whole job. His doubts are based in part on worries about "holism" (the view that symbols are local things, but meanings are not) and in part on "abduction" (how can a symbol system find the best theory to explain any set of data unless the answers are all already built into it in advance?) (So Fodor would not believe in the
computational component of such a hybrid symbol-grounding system either.)
[[(It should be added that Fodor seems to have little more faith in the explanatory usefulness of "modules"--despite the fact that he himself was responsible for popularizing the notion--than he does in nets or symbols [or brain function, for that matter]. We can define modules, in a theory-neutral way, as functionally independent components of a system, components whose design can be understood and modeled on their own, in isolation from the rest of the system. Perhaps because Fodor's own notion of modularity was inspired by UG [which was originally considered by Chomsky to be a functionally independent component of our language mechanism], the definition of "module" has been saddled with so many additional arbitrary stipulations--they must be innate, they must be "informationally encapsulated," they must not be influenced by what a person knows--that the word really has lost all its usefulness.)]]
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Are there grounds for all this Fodor's skepticism
about the only explanatory resources that cognitive science has at its disposal? It is certainly true that cognitive science has not even come close to solving any of its "easy" problems, such as explaining the functional basis of language or of meaning or of any other lifesize piece of human intellectual capacity or brain function. But it's also hard to know how fast it cognitive science ought to be explaining the mind, based on scientific track records elsewhere. Tononi &and Edelman have to be given the time to demonstrate whether or not their nets can do what associationism could not. do. Their nets are, after all, operating on inputs (sensorimotor and symbolic) inputs, not "ideas," (whatever those are).
And if symbols have their limitations, they also have their powers. No one can say in advance what hybrid systems can or cannot accomplish if their symbols are grounded in the sensorimotor world via category-learning networks. Changing the definition of just one word in a dictionary already propagates "holistically" to every other definition in the same dictionary. in which it figures. Change the sensorimotor grounding and the holistic effects
could be even more dramatic.
But if what you want to know is how and why it feels like something to have and exercise all those remarkable functional capacities, I am afraid you will be disappointed. Thatis is one unsolved mystery we all will just have to learn to live with.
Stevan Harnad is a professor of cognitive science at the University of Southampton in England.