From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.ecf!news-server.csri.toronto.edu!psych.toronto.edu!christo Tue May 12 15:50:17 EDT 1992
Article 5544 of comp.ai.philosophy:
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>From: christo@psych.toronto.edu (Christopher Green)
Subject: Re: Systems Reply I (repost perhaps)
Organization: Department of Psychology, University of Toronto
References: <1992May5.195616.28038@gpu.utcs.utoronto.ca> <6684@skye.ed.ac.uk> <1992May10.162915.23987@ccu.umanitoba.ca>
Message-ID: <1992May11.065930.10848@psych.toronto.edu>
Date: Mon, 11 May 1992 06:59:30 GMT

In article <1992May10.162915.23987@ccu.umanitoba.ca> zirdum@ccu.umanitoba.ca (Antun Zirdum) writes:
>In article <6684@skye.ed.ac.uk> jeff@aiai.ed.ac.uk (Jeff Dalton) writes:
>[stuff about Understanding]
>>
>>No I don't.  I can _conclude_ that it's not present.  Like this:
>>
>>   1. Computers can't understand.
>>   2. Mechanims M is necessary for understanding.
>>   3. Therefore computers lack M.
>>
>Hey, why not! Circular reasoning always works for me!
>(Computers can't understand, because they can't
>understand.)
>	This is no argument at all.

Get your fallacies right. This isn't circular, but it is a case of the 
fallacy of denying the antecedent:

~U
U->M
---
~M

If premise 2 were changed to: "Mechansims M are sufficient for understanding"
then the argument would be a perfectly valid modus tollens:

~U
M->U
---
~M

Logic Rules! :-)

-- 
Christopher D. Green                christo@psych.toronto.edu
Psychology Department               cgreen@lake.scar.utoronto.ca
University of Toronto
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