Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!ncar!gatech!bloom-beacon!CCH.BBN.COM!bnevin From: bnevin@CCH.BBN.COM (Bruce E. Nevin) Newsgroups: comp.ai.digest Subject: Consensus and Reality Message-ID: <19880609224137.7.NICK@INTERLAKEN.LCS.MIT.EDU> Date: 9 Jun 88 22:41:00 GMT Sender: daemon@bloom-beacon.MIT.EDU Organization: The Internet Lines: 117 Approved: ailist@ai.ai.mit.edu Date: Thu, 9 Jun 88 09:31 EDT From: Bruce E. Nevin Subject: Consensus and Reality To: ailist@ai.ai.mit.edu cc: hayes.pa@xerox.com, jmc@sail.stanford.edu, bn@cch.bbn.com In AIList Digest 7.24, Pat Hayes writes: PH> A question: if one doubts the existence of the physical world in which PH> we live, what gives one such confidence in the existence of the other I can't speak for Simon Brooke, but personally I don't think anyone seriously doubts the existence of the physical world in which we live. Something is going on here. The question is, what. One reason for our present difficulty in this forum reaching consensus about what "Reality" is, is that we are using the term in two senses: The anti-consensus view is that there is an absolute Reality and that is what we relate to and interact with. The consensus view is that what we "know" about whatever it is that is going on here is limited and constrained in many ways, yet we relate to our categorizations of the world expressing that "knowledge" as though they were in fact the Reality itself. When a consensual realist expresses doubt about the existence of something generally taken to be real, I believe it is doubt about the status of a mental/social construct, rather than doubt about the very existence of anything to which the construct might more or less correspond. From one very valid perspective there is no CRT screen in front of you, only an ensemble of molecules. Not a very useful perspective for present purposes. The point is that neither perspective denies the reality of that to which the other refers as real, and neither is itself that reality. What is being overlooked by those who react with such allergic violence to the notion of consensual reality is that there is a good relationship between the two senses or understandings of the word "real": namely, precisely that which makes science an evolving thing. John McCarthy has expressed it very well: JM> Indeed science is a social activity and all information comes in JM> through the senses. A cautious view of what we can learn would like to JM> keep science close to observation and would pay attention to the consensus JM> aspects of what we believe. However, our world is not constructed in JM> a way that co-operates with such desires. Its basic aspects are far JM> from observation, the truth about it is often hard to formulate in JM> our languages, and some aspects of the truth may even be impossible to JM> formulate. The consensus is often muddled or wrong. The control on consensus is that our agreements about what is going on must be such that the world lets us get away with them. But given our propensity for ignoring (that is, agreeing to ignore) what doesn't fit, that gives us lots of wiggle room. Cross-cultural and psychological data abound. For a current example in science, consider all the phenomena that are now respectable science and that previously were ignored because they could not be described with linear functions. But nature too is evolving, quite plausibly in ways not limited to the biological and human spheres. The universe appears to be less like a deterministic machine than a creative, unpredictable enterprise. I am thinking now of Ilya Prigogine's _Order Out of Chaos_. "We must give up the myth of complete knowledge that has haunted Western science for three centuries. Both in the hard sciences and the so-called soft sciences, we have only a window knowledge of the world we want to describe." The very laws of nature continue to reconfigure at higher levels of complexity. "Nature has no bottom line." (Prigogine, as quoted in Brain/Mind Bulletin 11.15, 9/8/86. I don't have the book at hand.) Now perhaps I am misconstruing McCarthy's words, since he starts out saying: JM> The trouble with a consensual or any other subjective concept of reality JM> is that it is scientifically implausible. Since everything else in that message is consistent with the view presented here, I believe he is overlooking the relationship between the two aspects of what is real: the absolute Ding an Sich, and those agreements that we hold about reality so long as we can get away with it. In this relationship, consensual reality is not scientifically implausible; it is, at its most refined, science itself. JM> It will be even worse if we try to program to regard reality as JM> consensual, since such a view is worse than false; it's incoherent. I suggest looking at the following for a system that by all accounts works pretty well: Pask, Gordon. 1986. Conversational Systems. A chapter in _Human Productivity Enhancement_, vol. 1, ed. J. Zeidner. Praeger, NY. For the coherent philosophy, a start and references may be found in another chapter in the same book: Gregory, Dik. 1986. Philosophy and Practice in Knowledge Representation. (In book cited above). Winograd & Flores _Understanding Computers and Cognition_ arrive at a very similar understanding by a different route. (Pask by way of McCulloch, von Foerster, and his own development of Conversation Theory; Winograd & Flores by way of Maturana & Varela (students of McCulloch) and hermeneutics.) JM> To deal with this matter I advocate a new branch of philosophy I call JM> metaepistemology. It studies abstractly the relation between the JM> structure of a world and what an intelligent system within the world JM> can learn about it. This will depend on how the system is connected JM> to the rest of the world and what the system regards as meaningful JM> propositions about the world and what it accepts as evidence for these JM> propositions. Sounds close to Pask's conversation theory. There is also a new field being advocated by Paul McLean (brain researcher), called epistemics. It is said to concern how we can know our "knowing organs," the brain and mind. "While epistemology examines knowing from the outside in, epistemics looks at it from the inside out." (William Gray, quoted in Brain/Mind Bulletin 7.6 (3/8/82). Bruce Nevin bn@cch.bbn.com