Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!usc!wuarchive!uunet!mcsun!ukc!edcastle!aipna!cam From: cam@aipna.ed.ac.uk (Chris Malcolm) Newsgroups: comp.ai.philosophy Subject: Re: Definition of (was Re: Testing for []) consciousness Message-ID: <3331@aipna.ed.ac.uk> Date: 23 Oct 90 19:28:28 GMT References: <27608@usc.edu> <1990Oct22.150143.13858@canon.co.uk> Reply-To: cam@aipna.ed.ac.uk (Chris Malcolm) Organization: Dept of AI, Edinburgh University, UK. Lines: 113 In article <1990Oct22.150143.13858@canon.co.uk> rjf@canon.co.uk writes: >In article mikeb@wdl31.wdl.fac.com (Michael H Bender) writes: >[..] >>I agree whole-heartedly -- either we can come up with a useful definition >>of consciousness, or else we should stop arguing whether machines can or >>can't have "it". >I'd like to suggest that something be ascribed consciousness iff it can >be the subject of experience: iff it is like something to be that >thing. (This is lifted from T Nagel, actual references not to hand but >available on request.) Nagel's notion is a lot better at capturing what we seem to be referring to when we use "consciousness" than some of the computational convolutions recently posted. So how could we use it? How can we know if it is "like something to be" -- for example -- this robot? It just isn't good enough to try to finesse this problem by making it subjective, as you have done: >If you think it is like something to be a bat, that the bat experiences ^^^^^ >anything, then you think the bat conscious; if not, then not. ^^^^^ Should AI ever succeed in making something with at least a superficially plausible claim to being conscious, there will be no lack of people who *think* it is conscious, and no lack of those who *think* it not. What we need is a way of finding out the truth! But suppose, as some have suggested, that "consciousness" is entirely subjective: that there cannot possibly ever be an objective test? This might turn out to be the case, but in comp.ai.philosophy we are engaged in pursuing the computational metaphor, the functional model of mind, to its limits, and it would be wrong of us to concede defeat on such a core tenet of our research programme without very strong evidence. What we do have is strong evidence suggesting that the concepts of consciousness, free will, and their like, are peculiarly hard to come to grips with, and have been that way for thousands of years. We are now sufficiently scientifically mature to know that this kind of cognitive intractability is a symptom of a science in the process of out-running the adequacy of its core concepts, a science entering the period of doubt and fluidity which presages a revolution. The Churchlands suggest that this is what is wrong, and that -- if we will just be patient -- the developing cognitive sciences will soon provide us with a decent tool-kit of elementary concepts with which to understand mentation. Then we will laugh at how silly we were, trying to use such ancient and muddled metaphors as "consciousness"! Let me suggest another possibility. Nicholas Humphrey has suggested that we are in fact provided with an organ of self-consciousness for a specific purpose. He points out the utility for any intelligent social animal of being an expert psychologist, i.e., being able to predict the behaviour of others. This led -- he suggests via evolution -- to the formation of an internal model of our kind of mind, which we can parameterise appropriately, and use to run simulations of other people's behaviour. He sees this in people, and in some apes. Of course, it might well be that this is not so much an inherited neurophysiological structure as a cognitive model which we (and some apes) happen to be smart enough to be able to create. And if we have such an internal model of mind, then of course we will be able to use it to predict our own behaviour as well as that of others. Just as the meaning of heard sentences, and the functional relationships of seen mechanisms, leap so effortlessly to mind as to seem properties of the words or world, so would such a model of mind operate, presenting us with so richly and vividly rendered an internal mental landscape as to suggest that the interior of our minds is indeed illuminated, that there is "someone at home", that it *is* "like something to be me", and so on. Without going into the details of the kind of mechanism suggested by Humphrey, Gilbert Ryle has suggested that in fact our knowledge of ourselves, our "subjectivity", is of *exactly* the same kind as our knowledge of other people, and that the qualitative jump in the richness and vivacity of our picture of ourselves compared to our picture of others -- which suggests to us the operation of a special faculty of "introspection" -- is no more than a natural consequence of the fact that we know very much more about ourselves than we do about anyone else. The fact that we can so easily be grossly mistaken about our own motives does suggest the operation of a cognitive faculty rather than some privileged "inner eye". Julian Jaynes has suggested that consciousness as we know it is a recent cultural invention, and that the ancient stories of gods speaking to men report a psychological reality, an architecture of mind, which we have since surpassed, save for those few unfortunate individuals who could not master the necessary psychological prestidigitation, and who languish in our madhouses still hearing the old voices. Now I don't wish to start an argument about the ideas of Jaynes or Humphrey, nor am I here supporting their ideas. What I do wish to suggest is, like the poster who pointed out the etymology of the word "conscious" ("knowing with", i.e. shared knowledge), that maybe consciousness is primarily a *social* psychological phenomenon, a cultural phenomenon, and that trying to seek its roots purely *inside* your own particular mind might be as silly and misguided as trying to put it into the mind of a machine. Gregory Bateson and William Powers have suggested in different ways that mind extends beyond the brain, beyond even the skin, ramifying out into the network of physical and social relationships maintained by it. If this is the case, then trying to discover the neurophysiological concomitants of mental faculties and properties is doomed to the same partial success as trying to build them into the computer we have chosen to be the brain of our robot. None of which means that we couldn't build a conscious robot or course, merely that it might be very hard to impossible if you start from a CS point of view :-) -- Chris Malcolm cam@uk.ac.ed.aipna 031 667 1011 x2550 Department of Artificial Intelligence, Edinburgh University 5 Forrest Hill, Edinburgh, EH1 2QL, UK