Path: utzoo!attcan!uunet!lll-winken!ames!mailrus!iuvax!cogsci!dave From: dave@cogsci.indiana.edu (David Chalmers) Newsgroups: comp.ai Subject: Re: Question on Chinese Room Argument Message-ID: <18073@iuvax.cs.indiana.edu> Date: 28 Feb 89 23:01:31 GMT References: <4298@pt.cs.cmu.edu> <17923@iuvax.cs.indiana.edu> Sender: root@iuvax.cs.indiana.edu Reply-To: dave@duckie.cogsci.indiana.edu (David Chalmers) Organization: Concepts and Cognition, Indiana University Lines: 94 harnad@elbereth.rutgers.edu (Stevan Harnad) writes: >dave@cogsci.indiana.edu (David Chalmers) writes: > >" with sense (1) [the high-level sense of "symbol"]... I reject the >" PREMISE of Searle's argument; a formal symbol-manipulator could never >" even display what _looked_ like competent Chinese-speaking behaviour. > >Well, this certainly gives away the store, and I'm inclined to agree. >But I have reasons. Do YOU have better reasons than that you like neurons >better than words? Certainly I have reasons. Have you got a couple of hours? I didn't think this was the time or the place for a switch of topic to an issue far more complex than Searle's misleading intuition pump. > >" [Searle] uses the word "symbol" in the low-level sense (2), while >" appealing to our intuitions about symbol-manipulators which manipulate >" high-level symbols of sense (1)!... But AHA - here we have him. These >" low-level (sense 2) symbols... correspond to micro-structural entities >" (such as neurons), which taken alone are devoid of semantics. Semantics >" only emerges when we put enough of these neurons together to form an >" incredibly complex SYSTEM. Despite the fact that the symbols taken >" alone are meaningless, put enough of them together in the right way and >" meaning will be an EMERGENT property of the system, just as it is with >" the human brain. > >What we have here is exactly what it sounds like: Not an argument, but >a statement of faith in the "emergent" properties of "incredibly >complex" systems. I feel the same way about clouds sometimes. > Answer me these questions. (1) Do you believe neurons (taken alone) have semantics. [I take it the answer has to be "No."] (2) Do you believe the brain as a whole has semantics. [I take it the answer is "Yes."] Given this, you must accept that semantics can arise out of non-semantic objects. Most of us are a little baffled as to how. It seems that the only half-way reasonable tack we can take to answer this question is to say that what is important for semantics (and the subjective in general) is not so much those objects as the complex patterns that they form. After all, neurons taken alone are pretty simple entities which can't carry much in the way of information. As is well known, information is carried by complexity (and the greater the complexity, the greater the information which can be carried). It seems to me that "information" and "semantics" are very closely related concepts. The fact that complexity is a necessary condition for information would suggest that appeals to complexity are not mere hand-waving. >[A correct brain simulation would] have to have the causal >wherewithal for interacting with the outside world the way brains and >planes do -- and that's not just symbols-in and symbols-out. They would >have to include transducers and effectors (which, as I said before, are >immune to Searle's Argument), and, if the other arguments I've been making >have any validity, it would have to include a lot more nonsymbolic >(analog, A/D, feature-detecting, categorical, D/A) processes in between >the input and the output too. This strikes me as rather like the point-missing "Robot Reply" in Searle, despite your disclaimers. I thought that the "Stephen Hawking argument" was a rather good reply to this stuff. What's important for subjective experience is a brain state, not a bodily state; and AI claims to be able to simulate any brain state whatsoever (just give it time). So Searle's arguments still would apply. You could paralyze me and put me in a sensory deprivation tank, but still (for some time at least) I would have subjective experience. >" It is a very mysterious question indeed how real understanding, >" subjective experience and so on could ever emerge from a nice physical >" system like the human brain... nevertheless we know that it does, >" although we don't know how. Similarly, it is a mysterious question how >" subjective experience could arise from a massively complex system of >" paper and rules. But the point is, it is the SAME question, and when we >" answer one we'll probably answer the other. > >The first case is certainly a mystery that is thrust upon us by the >facts. The second is only a mystery if we forget that there are no facts >whatsoever to support it, just the massively fanciful overinterpretation of >meaningless symbols. > And presumably, if we were all made of paper we'd say the same thing. "It's easier and safer to assume that neuro-thingies don't support TRUE experience; and after all we have no direct evidence for it, only their meaningless claims. So lets just ignore anything which these systems have in common (viz. extreme complexity, intelligent behaviour) and just concentrate on their differences." I don't want to be inflammatory, but it sounds not unlike many an argument used by a racist in days gone by. Dave Chalmers Center for Research on Concepts and Cognition Indiana University