Xref: utzoo sci.math:13657 comp.ai:8070 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!yale!cs.yale.edu!blenko-tom From: blenko-tom@cs.yale.edu (Tom Blenko) Newsgroups: sci.math,comp.ai Subject: Re: musings on Godel's theorem Message-ID: <27399@cs.yale.edu> Date: 26 Nov 90 04:27:06 GMT References: <11351@ccncsu.ColoState.EDU> <1990Nov25.204513.24169@nntp-server.caltech.edu> Sender: news@cs.yale.edu Followup-To: sci.math Organization: Yale University Computer Science Dept., New Haven, CT 06520-2158 Lines: 44 Nntp-Posting-Host: morphism.systemsz.cs.yale.edu Originator: blenko@morphism.CS.Yale.Edu In article <1990Nov25.204513.24169@nntp-server.caltech.edu> morphy@nntp-server.caltech.edu (Jones Maxime Murphy) writes: |news@ccncsu.ColoState.EDU (USENET News) writes: | |>This link between an axiomatic system and computation seems rather ill-defined |>and tenuous! (The philosopher Searle may be taking advantage of this with his |>... | |The link is hardly tenuous. A machine is defined by it's changes of state in |response to sentences from the language it accepts. The primitives of it's |language correspond to axioms, and syntax corresponds to an inferential |mechanism for extracting state changes from combinations of primitives. You've left me mystified. A computing machine reads a sequence of inputs, producing a sequence of outputs and halting or not halting. A logical theory consists of a set of axioms, rule(s) of inference, and a collection of theorems derivable from the axioms. Now, what is the "link"? What corresponds to the inputs, what corresponds to the outputs, and what corresponds to the computing machine? |I presume the one "truth" being referred to here is the impossibility of |a finistic proof of the consistency of arithmetic that can be embedded in the |language of arithmetic and the first-order predicate calculus. In addition to |simple culture shock at the news that "logic" as we know it is no longer |omnipotent in it's domain of inquiry, the fact is that we must now be wary in |the quest for artificial intelligence. | A great deal of human intelligence derives from self-reference, and weaknesses |in self-referential analysis in the inferential mechanisms of computing machines |which at the moment all rely on 1st order predicate calculus must be taken |seriously. Again, this argument is opaque. Intelligent entities exist, and their evolution/development presumably has proceeded with no prior knowledge of logical truths. If you wish to *describe* intelligent entities, artificial or otherwise, or to describe automobiles, toasters, or houseplants for that matter, you may find that some or all logics are unsuitable. If so, this is not a problem of automobiles, toasters, or houseplants, but a limitation of the logics in question. Tom