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From: cam@aifh.ed.ac.uk (Chris Malcolm)
Newsgroups: comp.ai.philosophy
Subject: Re: AGAINST FORMALISM?
Keywords: REASONING (is the keyword)!
Message-ID: <1991Jun17.032758.14030@aifh.ed.ac.uk>
Date: 17 Jun 91 03:27:58 GMT
References: <549@schoenfinkel.cscs.uwindsor.ca>
Reply-To: cam@aifh.ed.ac.uk (Chris Malcolm)
Organization: Dept AI, Edinburgh University, Scotland
Lines: 42

In article <549@schoenfinkel.cscs.uwindsor.ca> wsaba@cscs.uwindsor.ca (Walid Saba) writes:

>The
>debate should not be about the question of whether we should
>use logical reasoning or not? OF COURSE WE SHOULD! But what
>sort of reasoning? is the right question.

>For example, when being told  
>
>         Sam is pregnant.
>
>an "intelligent" system should infer some other facts.
>For example, 
>
>            =g=> Sam is a female

Illogical, Captain. Ectopic pregnancies can occur in males, and the
deliberate induction of ectopic pregnancies in human males is now being
considered as a way of sharing motherhood between the sexes.

>            =g=> Sam is alive

Illogical, Captain. Pregnant females do die, and if close enough to term
the live child can be safely removed from the dead pregnant mother.

>Is this "logical" reasoning? Of course.

Of course not.

The unfortunate problem with logic is not that it is deficient as a
system of reasoning, but that there are so few collections of english
language propositions about the world to which it can be usefully
applied. Usually it just gives silly results, as in the above example.
If logical reasoning had survival value we -- not to mention dogs and
cats -- would be a lot better at it. As it is, the kinds of informal
reasoning we naturally employ are pretty well fitted to the kind of
world we inhabit. And what kinds of reasoning do we employ? This is an
interesting open research topic. 
-- 
Chris Malcolm    cam@uk.ac.ed.aipna   +44 (0)31 667 1011 x2550
Department of Artificial Intelligence,    Edinburgh University
5 Forrest Hill, Edinburgh, EH1 2QL, UK                DoD #205