[Wittrs] Re: Is Computation too Static to Sustain a Mind?
- From: "gabuddabout" <gabuddabout@xxxxxxxxx>
- To: wittrsamr@xxxxxxxxxxxxx
- Date: Wed, 11 Aug 2010 23:55:40 -0000
--- In WittrsAMR@xxxxxxxxxxxxxxx, "BruceD" <wittrsamr@...> wrote:
>
>
> --- In Wittrs@xxxxxxxxxxxxxxx, "gabuddabout" <wittrsamr@> wrote:
>
> > We have a starting definition (of consciousness)
> > that awaits an analytic definition after enough empirical inquiry:
>
> Could you please give me other examples of starting definitions that
> after empirical inquiry allowed for an analytic definition.
Water is slippery stuff --> Water is H2O.
Also, and I
> hope I'm not asking too much, what empirical work do you have in mind
> that would allow for a definition of consciousness other than the
> ordinary one.
An analytic definition would be in the form of necessary and sufficient
conditions. Such can only be gotten empirically by looking at brains. You can
see then that finding such conditions won't be 100% conclusive yet we need not
worry about that too much. But before doing research, the ordinary def. of
consciousness as ontological subjectivity is just fine (substitute for favorite
ordinary one if you don't like "ontological subjectivity).
>
> > BP system can be given, willy-nilly, a computational description.
>
> How about a non-willy-nilly computational description. If a
> computational cognitive model has predictive power, is it or is not the
> best science for our buck?
Here's where I would want to make an important distinction. Any computational
model can be rewritten as a BP model or not. A computational model of mental
events causing other mental events might be viable if the right mechanisms are
found, in which case it is in virtue of physical mechanisms. The notion of a
computational mechanism just doesn't seem to make sense to me. If I conflated
computational mechanism with physical mechanism, then I would wonder at how
silly Searle must be to argue against "either."
>
> > given that we're after BP-type explanations
> > which don't need computational explanations.
>
> we just might want to reflect that the world doesn't necessarily bend to
> our conceptual dreams and we may have to give up the BP dream.
Funny, but it is the only game in town and this is easily seen when
functionalists argue that their functionalism is a physicalism, which means BP
or BP plus computation.
That
> doesn't mean giving up science, if by science one means prediction,
> control, and coherent account. Just means recognizing that not all
> natural phenomena fit into the procrustean bed of matter.
>
> bruce
Matter is a slippery matter but I don't hesitate to agree that it can appear to
be a procrustean bed of it. What does it matter that one makes science out of
it and no other? Does one have a choice? Perhaps one argues a priori that a
certain type of psychological theory is not viable. But that should be harder
work than Fodor sees Putnam doing below.
Anyway, I hope you get something from Fodor's review below:
Cheers,
Budd
A Science of Tuesdays
Jerry Fodor
The Threefold Cord: Mind, Body and World by Hilary Putnam
Columbia, 221 pp, £17.50, January 2000, ISBN 0 231 10286 0
Hilary Putnam's latest book collects two series of his lectures with two
chapters of `afterwords'. Subsidiary topics go by faster than my eye was able
to follow, but the main concerns are: `representational' theories of
perception, and `identity' theories of the mind/body relation.
The treatment of the mind/body issues, though the dialectic is often intricate,
is quite summary: neither philosophical claims for mind/body identity, nor the
denials of such claims, are `intelligible'. That's because `the notion of
identity has not been given any sense in this context' (sic). I'm not going to
discuss this part of Putnam's book because, truly, I haven't a clue what it is
to give a sense to a notion; the notion of giving a sense to a notion hasn't
been given a sense, either in this context or, as far as I know, in any other.
(I've been told that senses are sometimes given to concepts at Oxford after the
gates close to visitors; but that may be a leg-pull.) Nor am I clear what
you're supposed to do with a notion once a sense has been given it. There used
to be a story according to which empirical inquiry works by first giving senses
to notions, and then scouting around for something for the notions to apply to.
It was a sort of sophisticated version of Nanny's advice always to start by
defining one's terms. But I wouldn't have thought that anybody believes that
story any more; indeed, lots of us learned not to believe it from Putnam. What
a strange business philosophy is.
Putnam's discussion of representation and perception is, however, less abrupt.
I'll concentrate on that.
Common sense observes that typical states of the cognitive mind are
representational. The belief that the door is open represents the door as being
open, and is thus false if the door is closed; so far, credulity is unlikely to
be strained. But there is a venerable project, in both philosophy and
psychology, of trying to construct a general theory of the mind grounded in
this common sense observation. Such a theory would construe assignments of
content to mental states as hard facts in good standing, and mental processes
(thinking, perceiving and the like) as causal interactions among such
content-bearing states. The goal, in short, is to make predictive and
explanatory science out of commonsense mentalism. I don't know who first
thought up this research programme; quite possibly he lived in a cave. But its
avatars in current cognitive science are directly indebted to a philosophical
tradition that has been continuous at least since the 17th century. Occasional
flirtations with behaviourism not-withstanding, representational theories are
the mainstream tradition of Western thinking about the mind.
Putnam is not, however, an enthusiast for this mainstream tradition.
There is no reason to think that the idea of such a psychological theory . . .
is anything but utopian . . . The possibility of an ideal psychological theory
of this sort is nothing more than a `we know not what' . . . One hears a lot of
talk about cognitive science nowadays, but one needs to distinguish between the
putting forward of a scientific theory, or the flourishing of a scientific
discipline with well-defined questions, and the proffering of promissory notes
for possible theories that one does not even in principle know how to redeem.
And so forth at some length and with perceptible rancour.
I don't, myself, think that cognitive science is more in need of philosophical
defence than is, say, ornithology. The warrant of the enterprise, in both
cases, is not that the questions pursued are `well-defined', but the truths
that are discovered in the course of pursuing them. For someone who repeatedly
claims to be a pragmatist, Putnam is strangely insensitive to the
methodological truism that success is what justifies. If he really wants to
mount a respectable attack on cognitive science (or ornithology for that
matter) he has to show that the truths it claims to have discovered are
spurious, or that they can be explained just as well without appeals to
representational mental states and processes. That, however, would be hard
work, and Putnam doesn't even try. All of his arguments are a priori.
A representational theory of perception (hereinafter RTP) claims that the
cognitive relation between a creature and whatever it perceives is typically
causally mediated by mental representations of that object; `the disaster is
the idea that there has to be an interface between our cognitive powers and the
external world.' Whereas the undisastrous alternative, according to Putnam, is
the `direct' or `commonsense' realism about perception that he shares with such
of his `philosophical heroes' as Dewey, James (W.; certainly not H.), Peirce,
J.L. Austin, John McDowell, Husserl (with reservations) and, of course,
Wittgenstein. Disappointingly, however, neither Putnam nor anybody else in his
direct realist pantheon is prepared actually to offer an account of how
perception works. Rather, `in my opinion, "direct realism" is best thought of
not as a theory of perception but as a denial of the necessity for and the
explanatory value of positing "internal representations" in thought and
perception.' (Elsewhere, Putnam says that the defining question is whether, in
perception, `our cognitive powers . . . reach all the way out to the objects
themselves.' But this isn't much help, what with the notion of `reaching all
the way out' not having been given a sense in this context. Nor is it clear why
mentally representing the objects of perception isn't to count as one of our
cognitive powers.)
In fact, it's hard to see how one is even to begin to think about the mind
without thinking a lot about how it represents things. This is a point that's
been made repeatedly since Descartes and, as far as I can tell, it still
stands. Consider, for example, perceptual error. It's surely natural to say
that misperception is a failure of match between how the world is and how the
mind of the perceiver represents it. Putnam prefers a `disjunctive' account,
according to which `seeing an illusory pink elephant' is understood as `seeming
to see a pink elephant'. But he doesn't tell us how `seeming to see' is itself
to be construed unless in terms of representing. (There's a direct realist
story, owing to Austin, which construes seeming to see a such-and-such as being
disposed to believe that one is seeing a such-and-such. But it's a notorious
non-starter. When I find myself seeming to see pink elephants, what I am
disposed to believe is that I'm stewed.)
Or consider thinking. Is thinking about Granny also not a representational
state but a direct connection that reaches all the way out to the Old Dear? But
how could it be, since I can think of her when I'm here in New York and she is
in Ohio? Or what about remembering? How can I be in an unmediated relation to
Ebbets Field (alas, long since demolished); or to my erstwhile dentist, who
passed away a year ago in August? A last-ditch position might hold that direct
realism is a story that applies only to the explanation of veridical
perception. But if veridical perceiving is really that different from
everything else the mind does, how does one remember, or think about, what one
has veridically perceived? Thomas Reid, an 18th-century exponent of direct
realism, says that `the knowledge which I have of things past, by my memory,
seems to me as unaccountable as an immediate knowledge would be of things to
come; and I can give no reason why I should have the one and not the other, but
that such is the will of my Maker.' There's nothing I admire more in philosophy
than a well-bitten bullet. Reid is exactly right; but for the notion of mental
representation, much of what the mind does would be miraculous. The miracle
theory of mind is the natural alternative to the representational theory of
mind. Putnam gets no closer to facing this than not bothering to mention it.
In fact, there is no direct realist theory of perception (or of anything else
that's mental). So, willy-nilly, Putnam's polemic turns on whether the
indirect, representational theory of perception is intelligible; and, if it is,
whether it is defensible. At this point, there's need for a little background.
`The' representational theory of perception, like `the' representational theory
of mind itself, has had a long history and undergone many revisions and
extensions along the way. Putnam is, by and large, quite insensitive to the
differences between the various ways of running representational theories, but
they matter to the merits of his arguments. In particular, the sort of RTPs
that cognitive scientists endorse have shed a feature that traditional versions
of the doctrine, rationalist and empiricist, invariably took for granted: that
RTP must provide not just a psychology of perception but an epistemology, too.
That's to say, the same theory about representational mental states and their
causal interactions that answers questions like `how come, when a piano is in
front of me, and my eyes are open, and the lights are on, and the room isn't
filled with smoke . . . blah, blah, blah . . . I come to believe that I am
seeing a piano?' is also supposed to answer questions like `how come, when a
piano is in front of me, and my eyes are open, and the room isn't filled with
smoke . . . blah, blah, blah . . . I am justified in believing that I am seeing
a piano?' As it turns out, a lot of what was wrong with traditional RTPs was
the result of their attempt to bear this double burden.
Suppose that my (veridical) perception of a piano is mediated by an unconscious
causal sequence of mental representations that specify (e.g.) its apparent
shape, colour, size and so forth. (The early members of such sequences might be
an automatic consequence of the way that light bouncing off the piano
stimulates my sensory receptors; later members might be inferred from these
sensory representations together with my background beliefs.) Putnam apparently
thinks this sort of theorising is `science fiction', but there's no indication
that that is an informed opinion. Has he read (for example) David Marr's Vision
(1982)? Has he heard that there are honest-to-God theorems about the inference
from one-dimensional retinal representations to representations of
two-dimensional form; and from representations of two-dimensional form (and
motion) to representations of three-dimensional form? And that these theorems
predict a wide variety of previously unexplained perceptual phenomena? If
Putnam does know about Marr's kind of work and thinks it mistaken or confused,
why on earth doesn't he produce the arguments which show that it is? And if he
doesn't, what claim has his view of RTPs to the serious attention of busy
people?
But I digress. My point is that transformations of mental representations might
make an essential contribution to the causal process of perceptual belief
fixation even if the perceiver is unaware of them. But (arguably) they can't
contribute to the justification of perceptual belief unless the perceiver is
able to cite them. This being so, and given the assumption that RTPs must do
duty as epistemological theories, traditional versions required that we have
conscious access to the mental representations that mediate our perceptual
accomplishments. The (alleged) consciously accessible sensory representations
that serve as the premises of perceptual inferences are what epistemologists
used to call `sense data'. Since sense data must be available to perception
prior to the inferences that they ground, and since they are mental by
assumption, it often seemed to traditional RTPs that only mental things could
be perceived directly. Scepticism followed (as in Hume). There are, to be sure,
plenty of caveats one might enter to this line of thought. But it's quite true
that there are ways of running RTPs that can lead, and have led, either to the
view that `strictly speaking' nobody ever saw a piano, or to the view that
`strictly speaking' pianos are mental.
Having abandoned its claim to be epistemology, RTP doesn't need to say anything
like that now. We have perceptual knowledge of things in the world: inter alia,
pianos, tables, chairs, trees and their various surface colours. Causal
processes involving mental representations mediate these perceptual relations,
but you don't (typically) perceive the representations themselves either
directly or otherwise. Putnam is quite aware that this is the way that RTPs are
usually run these days, but he describes the concession to Realism as merely
terminological; it still doesn't make perception direct.
Well, that depends on what `direct' means, and I fear it hasn't been given a
sense in the present context. Putnam may be supposing that, in their (oh,
Lord!) `ordinary uses', `direct' and `mediated' name mutually exclusive ways
that a connection can be. But there really isn't any reason to suppose that. I
can step on your toe, even though both of our shoes mediate the transaction.
Likewise, I often talk to my wife on the phone. The connection we make is
certainly `mediated' in all sorts of ways; still, it is my wife that I talk to,
and it is her voice that I hear. (For what it's worth, the phone company calls
the service it provides `direct dialling'.) Any number can play the ordinary
language game, but nobody ever wins.
Putnam is one of our best philosophers, and he is terrifyingly smart. He simply
can't believe that the sorts of arguments he gives in The Threefold Cord are
serious reasons to abandon the best ? not to say the only ? way we know to
theorise about the mind. So what is going on in his book? In fact, it's a
skirmish in a much larger battle. The fundamental issue isn't direct perception
or even mental representation. It's whether meaning is a `natural kind'.
There are, as usual, two sorts of philosophers. One sort thinks that meaning is
a not-intrinsically-problematic property that some things have and other things
don't. Among the things that generally have it are, for example: words,
sentences, beliefs and thoughts. Among the things that generally don't have it
are, for example: rocks, clouds, cats and grass. What exactly meaning is, is a
hard problem. But we're working on it, and some bits do seem clear: for
example, that things that have meanings do so in virtue of their relational
properties. (Nothing is intrinsically meaningful, just as no one is
intrinsically a mother.) Maybe more about meaning will get clear as the inquiry
proceeds. Perhaps it will turn out that, among the things that have meanings,
are states of the nervous systems of perceivers, thinkers and other creatures
with minds. If so, that's what mental representations are.
Philosophers friendly to RTPs, and to cognitive science in general, hope that
that's the way it will turn out. Call that kind of philosopher a `meaning
realist'. His defining property is that he thinks there are facts about
meaning, and that they are suitable objects of scientific inquiry.
All the philosophers in Putnam's pantheon (and lots of others, including
Davidson, Quine, Dennett and more or less the entire populations of France and
Germany) don't believe any of that. Rather, they think that meaning arises from
our practices of interpretation, so that there no more needs to be a single
right answer to `what does "pinochle" mean?' than there is to `what does Hamlet
mean?' Our `interpretative practices', in turn, are paradigmatically those
involved in our use of language, so it is only for that context that semantic
notions have been given a sense. The supposition that brain states might have
meanings therefore lacks a sense and amounts to `nothing more than a "we know
not what."' For this sort of reason meaning is not a suitable object of
scientific inquiry (and for several other reasons, too, including its alleged
context-dependence and holism, and the heterogeneous character of the uses of
language to which meanings are assigned; Putnam takes all of that for granted,
though quite probably he shouldn't.) Trying for a science of meaning would be
silly; like trying for a science of games. Or of Tuesdays. Call this kind of
philosopher a `Wittgensteinian'.
It's as close as Putnam's book gets to having a saving grace that it almost
sees the clash between meaning realists and Wittgensteinians as its real topic.
(Only `almost' because, very unfortunately, Putnam consistently conflates the
argument over realism about meaning with a quite different argument over
reductionism about meaning. In fact, these issues are largely independent. Most
meaning realists are anti-reductionists, though you'd never guess that from
Putnam's exposition.) Well, who's right about meaning realism is a wide open
question; among the deepest, I think, that philosophers have thus far learned
how to ask. Putnam isn't the first to try to settle it a priori, but the a
priori arguments don't convince. Here again, one could wish that Putnam were
the pragmatist he claims to be. Pragmatists don't much hold with a priori
evaluations of what purport to be programmes of empirical research. It might
after all turn out that there are interesting things to be said about games; or
even about Tuesdays; or even about perception. Wittgenstein did, once, get
something right. He said: `Don't think, look.'
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