# AI, Penrose, and BBS (Cariani)

**URL:** <http://discourse.iapct.org/t/ai-penrose-and-bbs-cariani/772>\
**Category:** CSG1993\
**Created:** [September 28, 1993, 9:47pm UTC](http://discourse.iapct.org/t/ai-penrose-and-bbs-cariani/772 "1993-09-28T21:47:08Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Peter\_Cariani1](http://discourse.iapct.org/letter_avatar_proxy/v4/letter/p/5fc32e/32.png) [@Peter\_Cariani1](http://discourse.iapct.org/u/Peter_Cariani1)\
**Post date:** [September 28, 1993, 9:47pm UTC](http://discourse.iapct.org/t/ai-penrose-and-bbs-cariani/772/1 "1993-09-28T21:47:08Z")

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(From Peter Cariani)  
(To Bill Powers)  
Thanks for the BBS references (Shastri & Ajjanagadde; Penrose (Sept 93)) --  
I'll try to obtain the issue. Again, I apologize for my response time constant

> **···**
>
> --  
> I realize it's longer than most in this forum ....  
> &nbsp;&nbsp;&nbsp;I very much agree that much of the connectionist program is really not as  
> different from that of symbolic AI as they make it out to be (or as they might  
> like it to be). When you look closely at the mechanisms that are involved, you  
> see that they are all discrete, and their conception of knowledge not being  
> explicitly encoded is that instead of one symbol per object (or property) there  
> is some  
> more complex set of symbols and relations in place. They still are  
> "computationalists" in the most restricted sense of the term (i.e. discrete  
> operations on unambiguous tokens; formal procedures). [The more casual use of  
> the word "computation" as in "neural computation" is usually so vague and  
> unrestricted that it has all but rendered the concept meaningless.]  
> &nbsp;&nbsp;&nbsp;&nbsp;I had analogous discussions and debates within the artificial life  
> community over the genotype-phenotype distinction, which is really a digital-  
> analog distinction. The computationalists wanted to say that a more complicated  
> (yet still syntactic) relationship between genotype states and phenotypes in  
> their  
> simulations was what made these relationships "implicit" and "unpredictable"  
> rather than "explicit" and "predictable". Underlying these beliefs was a general  
> feeling that mere computational complexity confers upon a given system  
> mysterious powers ("unpredictability") and qualitatively different  
> structure ("life").  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The BIG difference between the connectionists and symbolic AI,  
> I think, should be their attitudes towards learning from past performance.  
> The connectionists at least embrace some form of adaptivity and learning,  
> using measures of past performance to change the structure of their devices.  
> Old ways of thinking die hard, however, and probably even a larger segment of  
> the connectionist community associates neural nets with particular, distributed  
> strategies of computing rather than adaptivity within an external (real,  
> unpredictable, ill-defined) environment. Thus scores of applied  
> mathematicians and computer scientists have steered neural net  
> models from the intellectual milieu of cybernetics and theoretical  
> neuroscience into one of optimization theory.  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;So Munsat's and your alternative (analog) accounts seem much more reason  
> able,  
> allowing for all of the perceptions related to an event to have some influence  
> on the  
> form of its memory representation (instead of encoding many little sensory atoms  
> and  
> their discrete connections).  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I would be utterly surprised, however, if Penrose is indeed on this same  
> track. He may be a fine mathematician, but he's a REALLY TERRIBLE philosopher  
> (that BBS would seriously consider his muddled platonic fantasies (which are not  
> testable)  
> and not perceptual control theory (which is testable) speaks reams about BBS,  
> their  
> priorities, and their intellectual values).  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Godel's Theorems apply only to potentially infinite systems of symbols,  
> which are physically not realizable, therefore they say NOTHING about the symbol  
> systems (implementable formal systems, computer programs and simulations,  
> information-processing operations embedded in biological organisms) that are  
> actually used in the material world (so Roger, where are the infinite tapes?).  
> It is even doubtful that the common (semantic) interpretations  
> of Godel's Theorems are reasonable even for potentially-infinite symbol systems  
> (see discussion of Wittgenstein's critique of Godel in S.G. Shanker's  
> "Wittgenstein and the Turning Point in the Philosophy of Mathematics",  
> SUNY Press, 1987).  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;I think when Penrose says "... such as the fact that the actual meaning  
> of  
> the symbol [inverted A] is to be 'for all natural numbers'" he REALLY believes  
> 1) that the (actually infinite) set of all natural numbers  
> exists independently of him and anyone else (i.e. Boss Platonic Reality)  
> and 2) that there is some logical relationship between the symbol  
> [inverted A] and this Platonic entity. Far from being grounded in some sort  
> of neural representation or even in some conception of analog processes,  
> or even in some conception of himself as an epistemic agent perceiving/acting  
> in the world, Penrose is really out there in la-la land.  
> He is trying to apply a set of concepts, which were meant to  
> deal with infinite sets of discrete symbol strings, to the brain,  
> which is neither infinite nor made up of discrete symbol strings.  
> I thought it was exceedingly embarassing that the New  
> York Times Book Review called "The Emperor's New Mind" "the most important book  
> in  
> 40 years" (which speaks reams about the science editors at New York Times Book  
> Review). It really seemed to me to be more evidence of an ongoing general  
> decline  
> in our scientific culture (this coupled with the current blathering in the  
> media of some theoretical physicists about God and the Big Bang). This is what  
> happens when we get out of the habit of demanding that scientific theories be  
> tested (in whatever way) by observations of the world (however obtained)--  
> science and religion quickly get blurred together.  
> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;But maybe we are turning a corner. There is a very good contemporary  
> critique of infinity by (former mathematician) Brian Rotman (I forget the exact  
> title, something like "From Zero to Infinity: On and on and on....",  
> Stanford University Press, 1993, $13 paper) and an equally incisive  
> critique of platonically-based "final theories" in physics  
> ("The End of Physics", Basic Books, 1993, $25 hard,  
> I forget the author's name -- he's an editor of Science).
> 
> Over & out,
> 
> -- Peter Cariani (9/28/93)