Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!decwrl!sun!pitstop!sundc!seismo!uunet!mcvax!ukc!etive!aipna!edai!cam From: cam@edai.ed.ac.uk (Chris Malcolm) Newsgroups: comp.ai Subject: THE MIND EXTENDS BEYOND THE SKIN Keywords: Mind, Brain, Robots, Searle Message-ID: <305@edai.ed.ac.uk> Date: 9 Mar 89 12:45:35 GMT Reply-To: cam@edai.ed.ac.uk (Chris Malcolm) Organization: Dept. of AI, Univ. of Edinburgh, UK Lines: 185 THE MIND EXTENDS BEYOND THE BRAIN AND BODY ------------------------------------------ I would like to introduce a new perspective to the Searle and symbol-grounding argument, which I hope will clarify some of the points which many of those disputing with Harnad fail to recognise, due to having too much experience of computers, and too little with real creatures, whether natural (biological) or artificial (robots). It is a nice argument by Gregory Bateson from the heyday of cybernetics to the effect that mind extends beyond the brain and even beyond the boundary of the creature (Searle's argument is a corollary, as is Harnad's "robotic functionalist" rebuttal). This is a theme further developed by the biologist Maturana, and used by Winograd and Flores, in the concept of "structural coupling" between a creature and its environment. I belong to that small but annoying company of roboticists who think that these considerations have direct implications for the architecture of even the simple and incompetent (relative to natural creatures) kinds of robots we can build with today's technology. In other words, there are some ways of building robots which are never going to work, and the issues underlying Searle's argument as well explicated by Harnad contain useful pointers to this. I will quote Bateson in detail, since the paper from which this nice argument comes is not otherwise of general (comp.ai) interest, and since it is clear that most comp.ai disputants never read papers anyway, even when they are central to the dispute :-) Gregory Bateson: We can assert that _any_ ongoing ensemble of events and objects which has the appropriate complexity of causal circuits and the appropriate energy relations will surely show mental characteristics. It will _compare_, that is, be responsive to _difference_ (in addition to being affected by the ordinary physical "causes" such as impact or force). It will "process information" and will inevitably be self-corrective either towards homeostatic optima or toward the maximisation of certain variables. A "bit" of information is definable as a difference which makes a difference. Such a difference, as it travels and undergoes successive transformation in a circuit, is an elementary idea. But, most relevant in the present context, we know that no part of such an internally interactive system can have unilateral control over the remainder or over any other part. The mental characteristics are inherent or immanent in the ensemble as a _whole_. Even in very simple self-corrective systems, this holistic character is very evident. In the steam engine with a "governor", the very word "governor" is a misnomer if it is taken to mean that this part of the system has unilateral control. The governor is, essentially, a sense organ or transducer which receives a transform of the _difference_ between the actual running speed of the engine and some ideal or preferred speed. This sense organ transforms these differences into differences in some efferent message, for example, to a fuel supply or a brake. The behavior of the governor is determined, in other words, by the behavior of the other parts of the system, and indirectly by its own behavior at a previous time. The holistic and mental character of the system is most clearly demonstrated by this last fact, that the behavior of the governor (and, indeed, of every part of the causal circuit) is partially determined by its own previous behavior. Message material (i.e. successive transforms of difference) must pass around this total circuit, and the _time_ required for the message material to return to the place form which it started is a basic characteristic of the whole system. The behavior of the governor (or any other part of the circuit) is thus in some degree determined not only by its own immediate past, but by what it did at a time which precedes the present by the interval necessary for the message to complete the circuit. There is thus a sort of determinative _memory_ in even the simplest cybernetic circuit. The stability of the system (i.e., whether it will act self-correctively or oscillate or go into runaway) depends upon the relation between the operational product of all the transformations of difference around the circuit and upon this characteristic time. The "governor" has no control over these factors. Even a human governor in a social system is bound by the same limitations. He is controlled by information from the system and must adapt his own actions to its time characteristics and to the effects of his own past action. Thus in no system which shows mental characteristics can any part have unilateral control over the whole. In other words, __the mental characteristics of the system are immanent, not in some part, but in the system as a whole__. The significance of this conclusion appears when we ask, "Can a computer think?" or, "Is the mind in the brain?" And the answer to both questions will be negative unless the question is focussed upon one of the few mental characteristics which are contained within the computer or the brain. A computer is self-corrective in regard to some of its internal variables. It may, for example, include thermometers or other sense organs which are affected by differences in its working temperature, and the response of the sense organ to these differences may affect the action of a fan which in turn corrects the temperature. We may therefore say that the computer exhibits mental characteristics in regard to its internal temperature. But it would be incorrect to say that the main business of the computer --- the transformation of input differences into output differences [i.e. symbol crunching]--- is "a mental process". The computer is only an arc of a larger circuit which always includes a man and an environment form which information is received and and upon which efferent messages from the computer have effect. This total system, or ensemble, may legitimately be said to show mental characteristics. It operates by trial and error and has creative character. Similarly, we may say that "mind" is immanent in those circuits of the brain which are complete within the brain. Or that mind is immanent in circuits which are complete within the system, brain _plus_ body. Or, finally, that mind is immanent in the larger system, man _plus_ environment. In principle, if we desire to explain or understand the mental aspect of any biological event, we must take into account the system - that is, the network of _closed_ circuits, within which that biological event is determined. But when we seek to explain the behavior of a man or any other organism, this "system" will usually _not_ have the same limits as the "self" - as this term is commonly (and variously) understood. [....] Consider a blind man with a stick. Where does the blind man's self begin? At the tip of the stick? At the handle of the stick? Or at some point halfway up the stick? These question are nonsense, because the stick is a pathway along which differences are transmitted under transformation, so that to draw a delimiting line _across_ this pathway is to cut off a part of the systemic circuit which determines the blind man's locomotion. [....] The total self-corrective unit which processes information, or, as I say, "thinks" and "acts" and "decides", is a _system_ whose boundaries do not at all coincide with the boundaries either of the body or of what is popularly called the "self" or "consciousness"; and it is important to notice that there are _multiple_ differences between the thinking system and the "self" as popularly conceived: 1. The system is not a transcendent entity as the "self" is commonly supposed to be. 2. The ideas are immanent in a network of causal pathways along which transforms of difference are conducted. The "ideas" of the system are in all cases at least binary in structure. They are not "impulses" but "information". 3. This network of pathways is not bounded with consciousness but extends to include the pathways of all unconscious mentation - both autonomic and repressed, neural and hormonal. 4. The network is not bounded by the skin but includes all external pathways along which information can travel. It also includes those effective differences which are immanent in the "objects" of such information. It includes the pathways of sound and light along which travel transforms of differences originally immanent in things and other people - and especially _in our own actions_. REFERENCES Gregory Bateson, section "The Epistemology of Cybernetics" in his paper "The Cybernetics of 'Self': A Theory of Alcoholism", in "Psychiatry", Vol 34, no 1, pp 1-18, 1971; reprinted in "Steps to an Ecology of Mind", Ballantine Books, NY, 1972. Stevan Harnad, "Minds, Machines, and Searle", J. Expt. Theor. Artif. Intell. 1(1989) pp5-25. H.R Maturana, F.J. Varela, ``The Tree of Knowledge: The Biological Roots of Human Understanding'', New Science Library, Shambala, Boston Mass., 1988. T. Winograd, F. Flores, ``Understanding Computers and Cognition'', Norwood, N.J. Ablex Publishing 1986. --------------------------------------------------------------------------- Chris Malcolm, Department of Artificial Intelligence, Edinburgh University. ---------------------------------------------------------------------------