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From: mark@umcp-cs.UUCP (Mark Weiser)
Newsgroups: talk.philosophy.misc
Subject: A and not A
Message-ID: <3539@umcp-cs.UUCP>
Date: Mon, 22-Sep-86 21:46:08 EDT
Article-I.D.: umcp-cs.3539
Posted: Mon Sep 22 21:46:08 1986
Date-Received: Sun, 28-Sep-86 23:43:20 EDT
Organization: Computer Sci. Dept, U of Maryland, College Park, MD
Lines: 26
Keywords: heidegger

So can one have a consistent system in which A and not A are both true?
Well, not in the technical sense of consistent, because it is defined
to NOT mean this.  So change consistent to mean workable, practical,
inspiring, enlightening.  Now what does it mean to say A and not A are
both "true"?  True is slippery concept here.  If true is defined as 
follows: "'A' is true iff A", assuming all the appropriate temporal
and situational caveats, then again a technical problem confronts
us in the meaning of 'iff', which will not permit both A and not A
to appear in the above definition and make sense.  So change truth
to mean: 'part of the possible existence of people".  NOW can
both A and not A be true?  Sure, you bet, even within the same person,
and I don't mean trivially because people can disagree.

A and not A can both be true, in a consistent system, within the definitions
above, because both A and not A are in fact always present.  There is
no A without not A (every foreground has its background, else it
is not present at all).  Therefore in a profound sense EVERY system must
have both A and not A true, else it has nothing in it at all.

(The above is loosely based on a long association with the thought of Heidegger.
I am responsible for the content, not him.  He's dead, after all.)
-mark
-- 
Spoken: Mark Weiser 	ARPA:	mark@maryland	Phone: +1-301-454-7817
CSNet:	mark@umcp-cs 	UUCP:	{seismo,allegra}!umcp-cs!mark
USPS: Computer Science Dept., University of Maryland, College Park, MD 20742