Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!cmcl2!rutgers!elbereth.rutgers.edu!harnad From: harnad@elbereth.rutgers.edu (Stevan Harnad) Newsgroups: comp.ai Subject: Re: Reply to Harnad re:Chinese Room Summary: On Causal "Powers": Objective and Subjective Message-ID: Date: 21 Feb 89 01:49:49 GMT References: <4317@pt.cs.cmu.edu> Organization: Rutgers Univ., New Brunswick, N.J. Lines: 74 kck@g.gp.cs.cmu.edu (Karl Kluge) of Carnegie-Mellon University, CS/RI write:; " What deeper point? [Searle's position] appears to be nothing but a " form of vitalism -- brains have these mysterious "causal powers" " without which understanding is not possible. It looks to me like the " normal sort of confusion one might expect from someone not used to " layered systems in which each layer interprets/runs the layer above it... The deeper point is that Searle's view is NOT vitalism but a reductio of a particular KIND of (putative) model of the mind: The kind advocated by "Strong AI." Searle has said repeatedly that he's not claiming that only brains could have the requisite causal powers, just that brains clearly DO and symbolic models (as shown by his Chinese Room Argument) clearly [sic] DON'T. It would require a grasp of this deeper point to realize why hand-waving about "layered systems" is NOT a satisfactory reply to this; it just misses the point and begs the question yet again. To show that symbolic models have mental powers (e.g., "interpreting") you can't just wave your hand and baptise them with it. [My own approach, in "Minds, Machines and Searle," has been to argue for replacing the mere Teletype version of the Turing Test with the full Robotic version -- the Total Turing Test (TTT), calling for all of our capacities, linguistic and nonlinguistic (e.g., sensorimotor). It turns out that because at least some of the functions of the system that successfully passes the TTT would have to be nonsymbolic, Searle couldn't simulate them, and hence the system would be immune to the Chinese Room Argument. This would not, of course "prove" (or even give empirical support of the usual kind for the hypothesis) that the system actually had mental powers, but it would capture as many of the causal powers of the mind or the brain that we could ever expect to capture empirically. The other deep implication of Searle's Argument is that it points out why a purely symbolic approach to mind-modeling is a nonstarter. It's useful to know that... It suggests you should try something else instead. I in turn describe an alternative hybrid approach to grounding symbolic representations bottom-up in nonsymbolic (analog and categorical) representations.] " No one cares what Searle does or doesn't understand when he is simulating a " physical symbol system capable of passing a written Turing Test in Chinese. " Period. If what Searle calls Strong AI is true I still wouldn't expect " Searle to understand Chinese in the Chinese room. First of all, SOME people apparently do care about this -- care enough to engage in some rather strained arguments to the effect that Searle (or "something/someone") IS understanding in the Chinese Room (see some of the postings that have appeared on this topic lately, and my replies to them). Not to care is either (1) not to care whether AI can capture understanding (which is fine, but then why should mind-modelers be discussing it with such modelers at all, any more than with auto mechanics? and why do such modelers persist in using words like "understanding" to describe their models?) or (2) it is not to care about the inconsistency of claiming that the computer understands but Searle doesn't, even though he is doing exactly the same thing the computer is doing! " Does Searle agree with you [about hybrid symbolic/nonsymbolic models]? " [In his response to] "The Brain Simulator Reply" [he says].. [y]ou have " to have those mysterious "causal powers" that neurons have. I am holding out for a model that captures all of the brain's OBJECTIVE powers, namely, its TTT powers, trusting that the subjective ones will piggy-back on them, or if not, accepting that we can never hope to be the wiser. Searle is holding out for something that captures ALL of the brain's powers, objective and subjective. We both agree on the essential point here, however, which is that symbolic models don't have the requisite powers. -- Stevan Harnad INTERNET: harnad@confidence.princeton.edu harnad@princeton.edu srh@flash.bellcore.com harnad@elbereth.rutgers.edu harnad@princeton.uucp BITNET: harnad@pucc.bitnet CSNET: harnad%princeton.edu@relay.cs.net (609)-921-7771