Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!rutgers!ames!hc!beta!cmcl2!philabs!pwa-b!mmintl!franka From: franka@mmintl.UUCP Newsgroups: sci.philosophy.tech Subject: Re: Incompleteness (was: Re: Uncertainty in life) Message-ID: <2173@mmintl.UUCP> Date: Mon, 8-Jun-87 22:44:00 EDT Article-I.D.: mmintl.2173 Posted: Mon Jun 8 22:44:00 1987 Date-Received: Sat, 13-Jun-87 08:01:34 EDT References: <6762@mimsy.UUCP> <3977@sdcc3.ucsd.EDU> <8135@ut-sally.UUCP> <1192@epimass.EPI.COM> <19216@ucbvax.BERKELEY.EDU> Reply-To: franka@mmintl.UUCP (Frank Adams) Organization: Multimate International, E. Hartford, CT. Lines: 19 In article <19216@ucbvax.BERKELEY.EDU> kube@cogsci.berkeley.edu.UUCP (Paul Kube) writes: >The upshot of Goedel's incompleteness theorem is the unprovability of >necessarily true statements, i.e., statements true in every model, for >sufficiently powerful systems. That there are *some* statements your >system can't prove is a good thing: but this is the requirement of >consistency, not completeness. First order predicate calculus is both >consistent and complete. Perhaps; but let us understand that "sufficiently powerful systems" means "second order systems" in this conclusion -- which is not at all the same as the "sufficiently powerful" requirement for the systems to which the incompleteness theorem itself applies to. And even then, every unprovable statement is false in some model if you fudge the definition of "model" a bit. -- Frank Adams ihnp4!philabs!pwa-b!mmintl!franka Ashton-Tate 52 Oakland Ave North E. Hartford, CT 06108