smoliar@vaxa.isi.edu (Stephen Smoliar) (07/13/90)
Before I left on my vacation, Tom Blenko had raised the issue of whether or not Searle was claiming any superiority of biological implementations over those of silicon regarding the issue of "understanding." Unless I am mistaken, he introduced this claim when he last spoke at UCLA. His basic claim was that there was something about the biological substrate which enabled the implementation of intentionality. He never said what that "something" was, but that did not prevent him from asserting that it was absent in any silicon implementation. Needless to say, I had trouble buying into this claim. ========================================================================= USPS: Stephen Smoliar USC Information Sciences Institute 4676 Admiralty Way Suite 1001 Marina del Rey, California 90292-6695 Internet: smoliar@vaxa.isi.edu "It's only words . . . unless they're true."--David Mamet
blenko-tom@CS.YALE.EDU (Tom Blenko) (07/13/90)
In article <14265@venera.isi.edu> smoliar@venera.isi.edu (Stephen Smoliar) writes: |Before I left on my vacation, Tom Blenko had raised the issue of whether or not |Searle was claiming any superiority of biological implementations over those of |silicon regarding the issue of "understanding." Unless I am mistaken, he |introduced this claim when he last spoke at UCLA. His basic claim was that |there was something about the biological substrate which enabled the |implementation of intentionality. He never said what that "something" |was, but that did not prevent him from asserting that it was absent in |any silicon implementation. Needless to say, I had trouble buying into |this claim. I said Searle's claim is that a system composed of a program running on a silicon processor need not be equivalent to the same program running on a biological "processor" (for the purposes of talking about intelligence). His argument goes like this: even if a program running on a silicon processor produced the same observable, extensional behavior as the biological system, there are intensional properties (emotional states of being happy, angry, alert, confused, and so forth) that he (and, he asserts, others) take as being essential to an intelligent entity. Searle's solution to the mind/body problem is that these intensional properties *are identically* collections of physical states of the underlying system. So an intensional property ("being hungry") is exactly some set of possible states of the system's neurons. The biological substrate doesn't "implement" the intensional properties, it exactly is the intensional properties. It follows that since the underlying states of the silicon and biological processors need not be equivalent, the systems constructed by applying them to the same program are not equivalent. Searle may have made stronger claims, he's not claiming (by this argument) that non-biological implementations of intelligence are unattainable, just that the specification of a program (independent of its processor) is insufficient. This is presented as an argument against "top-down" AI (my terminology) in its various guises. Tom
kenp@ntpdvp1.UUCP (Ken Presting) (07/16/90)
In article <14265@venera.isi.edu>, smoliar@vaxa.isi.edu (Stephen Smoliar) writes: > > Before I left on my vacation, Tom Blenko had raised the issue of whether or not > Searle was claiming any superiority of biological implementations over those of > silicon regarding the issue of "understanding." Unless I am mistaken, he > introduced this claim when he last spoke at UCLA. His basic claim was that > there was something about the biological substrate which enabled the > implementation of intentionality. He never said what that "something" > was, but that did not prevent him from asserting that it was absent in > any silicon implementation. Needless to say, I had trouble buying into > this claim. Stephen, you are again mistaken. Searle's PUBLISHED position on this issue is clear, unambiguous, and has been repeated in at least three articles. It is this: We know for a fact that brains think. We don't know at all whether anything else will ever think. Nobody in his right mind would deny the first assertion. That is the extent of the "superiority of biological implementations." You are only obscuring an already difficult issue with such irresponsible hearsay. Ken Presting ("Hearsay from the deaf and dumb?")
daryl@oravax.UUCP (Steven Daryl McCullough) (07/16/90)
In article <602@ntpdvp1.UUCP>, kenp@ntpdvp1.UUCP (Ken Presting) writes: > It is this: We know for a fact that brains think. We don't know at > all whether anything else will ever think. Nobody in his right mind > would deny the first assertion. That is the extent of the > "superiority of biological implementations." Let me temporarily leave my right mind behind so that I can argue this point. I would hesitate to say that "we know for a fact that brains think" until we agree on what counts for knowledge in something like this. The Strong AI proposal (which may or may not have been in Turing's mind when he proposed his Turing Test) is that we know that somebody or something is intelligent through observation of his/her/its behavior. If this is a legitimate criterion for knowledge of intelligence, then we do indeed know that brains think (and nothing else, so far). However, Searle denies the validity of using behavior as a test for intelligence. What else is there? Well, introspection: I know that I think because I experience myself thinking. This introspection doesn't get me any closer to knowing that *brains* (plural) think; only that *I* think. The only way that I can see to come to the conclusion that brains think is to apply the behaviorist criterion to other people, using oneself as a standard. Searle's prejudice towards "biological implementations" is evidenced by the fact that he is willing to accept a much weaker notion of proof of intelligence for humans than for computers. (Note: An argument that has been made on Searle's behalf is that intentional properties, such as the existence of mental states, are important for determining whether an entity is intelligent. However, Searle hasn't spelled out these properties, nor has he established that human brains enjoy them, so they cannot be considered the determining factor for Searle's conclusion that human beings think.) Daryl McCullough
dredick@bbn.com (Barry Kort) (07/17/90)
In article <602@ntpdvp1.UUCP> kenp@ntpdvp1.UUCP (Ken Presting) writes: > We know for a fact that brains think. We don't know at all whether > anything else will ever think. We conventionally define thinking as the kind of information processing that takes place in the human cerebral cortex. But I know of at least one member of the species (this author) who learned such thinking skills and subsequently taught some of them to other information processing systems, both carbon-based and silicon-based. (Well, the silicon-based systems have only gotten as far as inductive and deductive reasoning. I still don't know how to teach model-based reasoning to a machine.) Barry Kort bkort@bbn.com Visiting Scientist BBN Labs
dave@cogsci.indiana.edu (David Chalmers) (07/19/90)
In article <602@ntpdvp1.UUCP> kenp@ntpdvp1.UUCP (Ken Presting) writes: >Stephen, you are again mistaken. Searle's PUBLISHED position on this issue >is clear, unambiguous, and has been repeated in at least three articles. > >It is this: We know for a fact that brains think. We don't know at all >whether anything else will ever think. Nobody in his right mind would deny >the first assertion. That is the extent of the "superiority of biological >implementations." > >You are only obscuring an already difficult issue with such irresponsible >hearsay. This statement of Searle's position does not tell the whole truth. It is true that Searle does not claim to have *proved* any privileged role for biology. However, his intuitions about the matter are another story. Check out these excerpts: "Whatever intentionality is, it is a biological phenomenon, and it is as likely to be as causally dependent on the specific biochemistry of its origins as lactation, photosynthesis, or any other biological phenomenon." -- BBS, 1980, p. 424. "The upshot of this discussion is to remind us of something that we have known all along: namely, mental states are biological phenomena. Consciousness, intentionality, subjectivity and mental causation are all a part of our biological life history, along with growth, reproduction, the secretion of bile, and digestion." -- _Minds, Brains and Science_, p. 41. "Brains are specific biological organs, and their specific biological properties enable them to cause consciousness and other sorts of mental phenomena." -- Scientific American, Jan 1990, p. 29. -- Dave Chalmers (dave@cogsci.indiana.edu) Concepts and Cognition, Indiana University. "It is not the least charm of a theory that it is refutable"
kenp@ntpdvp1.UUCP (Ken Presting) (07/23/90)
In article <51408@iuvax.cs.indiana.edu>, dave@cogsci.indiana.edu (David Chalmers) writes: > In article <602@ntpdvp1.UUCP> kenp@ntpdvp1.UUCP (Ken Presting) writes: > > > . . Searle's PUBLISHED position on this issue is: > >. . . We know for a fact that brains think. We don't know at all > >whether anything else will ever think. Nobody in his right mind would deny > >the first assertion. That is the extent of the "superiority of biological > >implementations." > > This statement of Searle's position does not tell the whole truth. It > is true that Searle does not claim to have *proved* any privileged role > for biology. However, his intuitions about the matter are another story. > Check out these excerpts: Dave, I hope you will agree that no argument against AI based on the superiority of biological implementations could have much interest, and that we'll get further with the CR if we drop the issue of biology. But I don't want to leave the impression that Searle is promoting just his intuitions, or that he has a hidden vitalist agenda. So here are some more quotes: > > "Whatever intentionality is, it is a biological phenomenon, and it is as likely > to be as causally dependent on the specific biochemistry of its origins as > lactation, photosynthesis, or any other biological phenomenon." > -- BBS, 1980, p. 424. Same article, right after the "Many Mansions" reply: Perhaps other physical and chemical processes could produce exactly these effects ... That is an empirical question, rather like the question whether photosynthesis can be done by something with a chemistry different from that of chlorophyll. > > "The upshot of this discussion is to remind us of something that we have known > all along: namely, mental states are biological phenomena. Consciousness, > intentionality, subjectivity and mental causation are all a part of our > biological life history, along with growth, reproduction, the secretion > of bile, and digestion." > -- _Minds, Brains and Science_, p. 41. > Same book, same page: Of course, some other system might cause mental processes using entirely different chemical or biochemical features from those the brain in fact uses. > "Brains are specific biological organs, and their specific biological > properties enable them to cause consciousness and other sorts of mental > phenomena." > -- Scientific American, Jan 1990, p. 29. > Same article, same page: As a matter of fact, cognition is a biological phenomenon: mental states and processes are caused by brain processes. This does not imply that only a biological system could think ... Searle is not a vitalist ideologue, nor is he a Cartesian reactionary. He is just another guy with another argument, just like the rest of us. Ken Presting ("Ad Calculem")
djones@megatest.UUCP (Dave Jones) (08/10/90)
From article <602@ntpdvp1.UUCP>, by kenp@ntpdvp1.UUCP (Ken Presting): > ... We know for a fact that brains think. We don't know at all > whether anything else will ever think. 'Scuse me. Exactly what is this 'thinking' that brains do but other things can't? How can you tell if something is thinking or not?