ISSSSM%NUSVM.BITNET@CUNYVM.CUNY.EDU (Stephen Smoliar) (06/14/91)
In article <1991Jun13.163734.10165@cs.yale.edu> mcdermott-drew@cs.yale.edu (Drew McDermott) writes: > In article <1991Jun12.232457.2962@news.media.mit.edu> > minsky@media-lab.media.mit.edu (Marvin Minsky) writes: > >Conversants never do, in > >fact, know that they are talking about the same things. It is always > >a matter of convention, convergence, and good fortune -- even in the > >case of "mathematical truths". When you and I both talk about "that > >chair over there", our internal models differ substantially, but not > >enough to make most practical interactions too difficult. And the > >cchir itself changes imperceptibly from one moment to the next as it > >loses and gains atoms and suffers thermal agitations of its internal > >degrees of freedom. There is no chair, indeed, from a modern physical > >point of view, only boundaries imposed by observers.... > >Okay, but what about this objection: There are no observers, indeed, >but only boundaries imposed by .... who?? > >Why do we grant such rock-solid existence to observers and not to >chairs? > >Surely we're not genuflecting toward the almighty self here? > >I think this is a genuine conundrum, but whatever solution we work out >for explaining why people are objectively real will also work for >chairs. In any case it will not do to say that the reality of >macroscopic objects is merely imposed by an observer, because the >observer is itself just another macroscopic object. > Poor Descartes! All that business about separating out mind and body has really been taking quite a beating lately. Now, just when you thought it was safe to go into the philosophy library, here comes Drew ready to take on the COGITO! By the time we are all done with him, all Descartes will have left to his name will be a few fragments of analytic geometry (pathetically Euclidean, at that)! However, if we can overcome our fear of solipsism (or at least Chris Hutchison's fear), perhaps the COGITO is not quite as arbitrary as Drew's accusation makes it out to be. Ultimately, it all boils down to this question of whether or not "genuflecting toward the almighty self" is nothing more than blind faith. After all, what the COGITO is basically saying is that because I am exercising my "mental powers" (whatever they may be), I can attribute to myself a "rock-solid existence" which I cannot attribute to that chair I observe over there. As I see it, here is where solipsism comes in the door to prop up the COGITO: The question, as Drew formulated it, is quite appropriate. Why should the class of observers be any better off than the class of chairs? The answer provided by solipsism is that they are not any better off. However, there is ONE observer who IS better off; and that is Drew's "almighty self." The solipsistic argument goes that the self is the ONLY observer that needs to be taken into account. Any other observers do, indeed, have the same status as chairs: They are all products of the interpretative process which constitutes observation. The COGITO then goes one step further by basically asserting that the "self" behind that interpretative process is essentially an emergent property of the process. This is a bit convoluted and kind of heady. It is probably better discussed in a congenial bar over a few beers. However, I do not see it as a patently silly point of view which may impede our attempts to make progress in artificial intelligence. Minsky is quite right that we should "get on with the work of making machines that can solve problems and communicate with one another as best they can." As we learn more about the technology of situated automata, it becomes more and more feasible to think of building those machines on a foundation of solipsism. Indeed, from a point of view of sound engineering, there may be no other viable way in which to build them. =============================================================================== Stephen W. Smoliar Institute of Systems Science National University of Singapore Heng Mui Keng Terrace, Kent Ridge SINGAPORE 0511 BITNET: ISSSSM@NUSVM "He was of Lord Essex's opinion, 'rather to go an hundred miles to speak with one wise man, than five miles to see a fair town.'"--Boswell on Johnson
spratt@hawk.cs.ukans.edu (Lindsey Spratt) (06/14/91)
Is the "situated automata" mentioned by Smoliar related to Barwise's idea of situated inference as presented in "Unburdening the Language of Thought" (in "The Situation in Logic" by Jon Barwise, CSLI, 1988)? Was Minsky's lambast about "growing" beyond the "childish, primitive, religious" concerns for truth meant to include non-classical logical and philosophical approaches such as situation theory and semantics? A response from either Smoliar or Minsky would be particularly appreciated.
minsky@media-lab.media.mit.edu (Marvin Minsky) (06/15/91)
In article <1991Jun14.151446.20698@hawk.cs.ukans.edu> spratt@hawk.cs.ukans.edu (Lindsey Spratt) writes: > >Was Minsky's lambast about "growing" beyond the "childish, primitive, >religious" concerns for truth meant to include non-classical logical >and philosophical approaches such as situation theory and semantics? That was a pretty childish remark of mine. I do think that the term "truth" has too many uses to be usable in technical discussions. Yes, we can all agree that Mickey is not a real mouse -- and if we want, we can go on to say things like "'Mickey is not a real mouse' is true." But this is like pretending, in biology, that "alive" has a meaning because we agree that tigers are alive and stones are not. The important and practical problems always come in the fuzzy areas. I summarized my grumble with formal logic recently in an article in the curret AI magazine, and another one in the current Artificial INtelligence journal. I'll just quote from the first one: These limitations of logic begin at the very foundation, with the basic connectives and quantifiers. The trouble is that worldly statements of the form, ``For all $X$, $P(X)$,'' are never beyond suspicion. To be sure, such a statement can indeed be universally valid inside a mathematical realm---but this is because such realms, themselves, are based on expressions of those very kinds. The use of such formalisms in AI have led most researchers to seek ``truth'' and universal ``validity'' to the virtual exclusion of ``practical'' or ``interesting''---as though nothing would do except certainty. Now, that is acceptable in mathematics (wherein we ourselves define the worlds in which we solve problems) but, when it comes to reality, there is little advantage in demanding inferential perfection, when there is no guarantee even that our assumptions will always be correct. Logic theorists seem to have forgotten that any expression like ($\forall X$)($PX$), in actual life---that is, in a world which we find, but don't make---must be seen as only a convenient abbreviation for something more like this: "For any thing $X$ being considered in the current context, the assertion $P{X}$ is likely to be useful for achieving goals like $G$, provided that we apply in conjunction with certain heuristically appropriate inference methods." In other words, we cannot ask our problem-solving systems to be absolutely perfect, or even consistent; we can only hope that they will grow increasingly better than blind search at generating, justifying, supporting, rejecting, modifying, and developing ``evidence'' for new hypotheses. ------ TO be more constructive, what I'm saying is that there is something wrong with the "basic" concept of instantiation -- and generalization. Instead of doing "deductions" which require that sort of idea, I'm saying that thinking is more centered around plausible matching, concepts of similarity, heuristics of modifying descrptions, and so forth. My complaint is that the two dominant ideas of logic -- and I just don't know whether the situation is different in "situational" theories -- of *instantiation* and of *universal (or existential) quantification* are rather low on my list of useful devices for cognition.
ISSSSM@NUSVM.BITNET (Stephen Smoliar) (06/15/91)
In article <1991Jun14.151446.20698@hawk.cs.ukans.edu> spratt@hawk.cs.ukans.edu (Lindsey Spratt) writes: > >Is the "situated automata" mentioned by Smoliar related to Barwise's >idea of situated inference as presented in "Unburdening the Language >of Thought" (in "The Situation in Logic" by Jon Barwise, CSLI, 1988)? > The attribute "situated" is coming to mean a variety of things, some one which are related, in artificial intelligence these days. Barwise seems to be more committed to formal logic than to the sorts of issues of behavior which have been occupying my own thoughts. A good picture of the current lay of the land can be found in Brian Smith's article, "The owl and the electric encyclopedia," which was published in the January 1991 issue of ARTIFICIAL INTELLIGENCE. =============================================================================== Stephen W. Smoliar Institute of Systems Science National University of Singapore Heng Mui Keng Terrace, Kent Ridge SINGAPORE 0511 BITNET: ISSSSM@NUSVM "He was of Lord Essex's opinion, 'rather to go an hundred miles to speak with one wise man, than five miles to see a fair town.'"--Boswell on Johnson