Re: Logic

From: Philip Jonkers (P.A.E.Jonkers@phys.rug.nl)
Date: Thu Jul 26 2001 - 11:13:36 BST

  • Next message: Philip Jonkers: "Re: Logic" 

    Received: by alpheratz.cpm.aca.mmu.ac.uk id LAA12709 (8.6.9/5.3[ref pg@gmsl.co.uk] for cpm.aca.mmu.ac.uk from fmb-majordomo@mmu.ac.uk); Thu, 26 Jul 2001 11:16:10 +0100
From: Philip Jonkers <P.A.E.Jonkers@phys.rug.nl>
X-Authentication-Warning: rugth1.phys.rug.nl: www-data set sender to jonkers@rugth1.phys.rug.nl using -f
To: memetics@mmu.ac.uk
Subject: Re: Logic
Message-ID: <996142416.3b5fed50c062a@rugth1.phys.rug.nl>
Date: Thu, 26 Jul 2001 12:13:36 +0200 (CEST)
References: <Pine.WNT.4.33.0107241151260.177-100000@C157775-A.frndl1.wa.home.com>
In-Reply-To: <Pine.WNT.4.33.0107241151260.177-100000@C157775-A.frndl1.wa.home.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
User-Agent: IMP/PHP IMAP webmail program 2.2.5
X-Originating-IP: 129.125.13.8
Sender: fmb-majordomo@mmu.ac.uk
Precedence: bulk
Reply-To: memetics@mmu.ac.uk

    Quoting TJ Olney <market@cc.wwu.edu>:

    > Perhaps the difficulty is that there are many kinds of logic.
    > The following represents one that Bateson labeled (for reasons
    > I'd enjoy knowing), logic in Barbara.
    >
    > Men die.
    > Grass dies.
    > Men are grass.
    >
    > It is just as "logical" as the more common syllogistic form,
    > but represents a different "kind" of logic.
    >
    > All men die.
    > Socrates is a man.
    > Socrates must die.

    I would say the former is not logic at all, the latter,
    of course, is.
    Let's look at the first exhibition of `logic'. The first
    premises are perfectly rational, but the conclusion is irrational.
    Look at it symbolically:

    We have the following perfectly logical premises:
    1. Men -> die
    2. Grass -> die
    3. die NOT-> grass (:`death' does not lead to `grass')

    The conclusion:
    Men -> grass

    is valid iff
    Men -> die -> grass

    which is in contradiction with premise 3. Therefore `logic in
    Barbara' is no logic at all. Well, at least your statement of
    it. Please TJ don't smear such a nice name with pretentious
    intent (my sister has the same name!).

    The second one is trivially sound:

    ALL elements of the set of men -> die
    Socrates is an element of the set of men ->
    Socrates -> dies

    So having invalidated your first suggestion of logic, do you
    have more in store for me? I'm a firm believer in a single
    kind of logic (a real one, anyway). Wouldn't we have multiple
    kinds of mathematics, if we had more versions of logic?

    Cheers,

    Philip Jonkers.

    ===============================================================
    This was distributed via the memetics list associated with the
    Journal of Memetics - Evolutionary Models of Information Transmission
    For information about the journal and the list (e.g. unsubscribing)
    see: http://www.cpm.mmu.ac.uk/jom-emit

    This archive was generated by hypermail 2b29 : Thu Jul 26 2001 - 11:20:16 BST