Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!rutgers!ucla-cs!zen!ucbvax!cogsci.berkeley.edu!kube
From: kube@cogsci.berkeley.edu (Paul Kube)
Newsgroups: sci.philosophy.tech
Subject: Simplicity and truth (was: Re: Science and Aesthetics)
Message-ID: <20194@ucbvax.BERKELEY.EDU>
Date: Thu, 20-Aug-87 17:23:53 EDT
Article-I.D.: ucbvax.20194
Posted: Thu Aug 20 17:23:53 1987
Date-Received: Sat, 22-Aug-87 11:56:43 EDT
References: <120@snark.UUCP> <86@thirdi.UUCP> <8707@ut-sally.UUCP> <20070@ucbvax.BERKELEY.EDU> <8727@ut-sally.UUCP>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: kube@cogsci.berkeley.edu.UUCP (Paul Kube)
Organization: University of California, Berkeley
Lines: 39
Keywords: simplicity elegance beauty truth ockham's razor

In article <8727@ut-sally.UUCP> turpin@ut-sally.UUCP (Russell Turpin) writes:
>Ockham's razor is a demand for parsimony of assumptions. Whether
>or not one finds it compelling is a philosophic debate over which
>much paper has been dirtied (and bits flipped.) But it is a
>philosophic, as opposed to aesthetic, principle.

Philosophic it may be, but so far it is just a pronouncement of taste,
like Quine's preference for desert landscapes.  I was wondering if you
had an argument.

>In my original
>posting, I made it clear that I was talking about two physical
>theories which (a) had identical explanatory power and (b) one of
>which required logically weaker physical assumptions (laws). 

No, you did not make this clear.  You talked about three cases: A pair
of equiexplanatory theories, one of which makes fewer unexplained
assumptions than the other; a pair of equiexplanatory theories
which make the same assumptions but one; and a pair of equiexplanatory
theories which make all the same assumptions.  Entailment relations
between the assumption sets wasn't mentioned, nor were assumptions
equated with `laws'.

>In short, the other theory is making physical assumptions that
>provide no additional explanatory power. Since belief in physical
>laws is justified (in many epistemologies) by reference to their
>explanatory power (amongst other things), these extra assumptions
>(putative laws) should be rejected. (This, of course, is just a
>restatement of a strict version of Ockham's razor.)

Now this is an argument, but it's not an argument for Ockham's razor.
It's an argument for not believing theories that make assumptions that
play no explanatory role.  But a theory may make more assumptions
(even logically stronger ones) than another, and yet have each of its
assumptions play an explanatory role.  Ockham's razor enjoins us to
disbelieve the first theory, other things being equal; and I'm still
wondering if there's an argument for it.

--Paul kube@berkeley.edu, ...!ucbvax!kube