Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!brutus.cs.uiuc.edu!rpi!uupsi!cmcl2!rutgers!aramis.rutgers.edu!athos.rutgers.edu!nanotech From: alan@oz.nm.paradyne.com (Alan Lovejoy) Newsgroups: sci.nanotech Subject: Re: Review of Penrose's review of Moravec Message-ID: Date: 25 Jan 90 01:08:58 GMT Sender: nanotech@athos.rutgers.edu Organization: AT&T Paradyne, Largo, Florida Lines: 110 Approved: nanotech@aramis.rutgers.edu In article josh@cs.rutgers.edu writes: >Penrose claims that there are three cases to consider, first, the >"Strong AI" position with which he labels Moravec; secondly, the >anti-AI position of Searle et al, and finally his own hypothesis that >consciousness consists of the brain's performing some non-computable >calculation with the aid of some unexplained phenomenon of quantum >mechanics. >Penrose paints two pictures, one he believes horrific in which >Searle is correct, but AI succeeds, and we all upload into machines >which are not conscious. The machines continue to act in grotesque >parody of real people, but true consciousness has died. > >He doesn't actually believe this, however, but rather that because >(as he contends in tENM) consciousness depends on non-computational >properties of QM, "computers will never be able to achieve genuine >understanding, insight, or intelligence, [and that] human beings >will [continue to] supply the guidance, the motivation, and the >'being' of society." Why is the assumption made that natural brains either might, or must, have recourse to some device or physical phenomena that artificial brains can not use? The fact that the Motorolas of the world have yet to construct an artificial brain which works like a natural brain does not prove that natural brains rely on qualitatively different physical principles than do artificial ones. And it certainly does not prove that artificial brains could not be constructed using the same physical phenomena, processes, principles and devices used by natural brains. Since natural brains can be constructed, what prevents the construction of artificial brains using the same mechanisms employed in the construction of natural ones? What law of nature permits the design (by evolotion) of natural brains but prevents the design (by application of the scientific method) of artificial brains? It must be conceded that we don't know, or don't know that we know, all the significant facts about how natural brains work. Our best artificial brains cannot match many of the capabilities of even rather modest natural brains. However, artificial brains can and do match, even overmatch, many of the capabilities of natural brains. And every generation of artificial brains is more capable than the preceding generation. Also, research is continuing into the inner workings of natural brains, and it is resulting in an explosion of new knowledge which is being used to construct ever-better artificial brains. So yes, there is still a qualitative difference between natural brains and artificial brains. But there is no basis for therefore concluding that all future attempts to fully emulate the operation of a natural brain are doomed to failure simply because it has not been done up to now; and as long as progress continues, *THERE WILL BE NO SUCH BASIS*. There are many things that we don't know. But that does not mean that they are forever unknowable. There are things "known" to be unknowable (although that is subject to change), but there is no indication (let alone proof) that the mechanisms of consciousness are such. Some people seem to have a deep emotional need to believe that their brain is a magical instrument which cannot be duplicated by human engineers. This need drives them to conjure up theories and hunt for facts in support of their belief, instead of letting experimental evidence and common sense lead them to correct conclusions. They already know what they believe; their understanding of reality is filtered through their bias. The real fear, which is just badly stated, is that it will be possible to construct artificial brains which emulate the observed behavior of natural brains without bestowing true consciousness on the artificial brains. Since our only test for conscousness is observable behavior (unless the Japanese or the University of Utah discover telepathy :-) :-)), we could easily fail to detect this crucial deficiency. It is NOT clear that identical behavior proves identical internal phenomena. Whether it is possible at all to bestow consciousness on artificial brains is really a separate issue. >This I can live with. Searle's position poses no terror for me >as a candidate uploader; it is too obviously the rationalization >of an anthropocentric epistemology. Penrose, on the other hand, >has simply posed a testable hypothesis: if we can build 'em smart, >he's wrong. Behavior is testable. But is consciousness? We can't even DEFINE it, let alone test for it. It reminds one of the old saw about intelligence tests: intelligence is whatever intelligence tests measure. Ah, but what do intelligence tests *REALLY* measure?! But then, the same issue could be raised in other contexts. How do I know that all of you are conscious? I *KNOW* I'm conscious; but lacking telepathy, the only way I can test *YOU* for consciousness is to observe your behavior. Or is it? I can also note the fact that you and I are *VERY* similar. Similarly, artificial brains which behave like natural ones AND WHICH OPERATE ON THE SAME PRINCIPLES, USING THE SAME MECHANISMS, STRUCTURES AND PROCESSES as natural brains, almost certainly produce the same internal phenomena, such as consciousness. ____"Congress shall have the power to prohibit speech offensive to Congress"____ Alan Lovejoy; alan@pdn; 813-530-2211; AT&T Paradyne: 8550 Ulmerton, Largo, FL. Disclaimer: I do not speak for AT&T Paradyne. They do not speak for me. Mottos: << Many are cold, but few are frozen. >> << Frigido, ergo sum. >> [(a) Penrose does not claim that it would be impossible to build artificial minds using his unknown phenomenon. Indeed he explicitly allows that that might happen when and if the phenomenon were actually discovered. He simply believes that such a difference does exist between the kind of computers we have now and ones that would be capable of consciousness. (b) I think the remarks about some people's need to believe that the brain is magical therefore apply more to Searle than to Penrose. However, there definitely are such people. (c) As regards testability, remember Penrose said "computers will never be able to achieve genuine understanding, insight, or intelligence...". That is subject to objective determination no matter whether they achieve consciousness or not. --JoSH]