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From: ma188saa@sdcc3.UUCP
Newsgroups: sci.philosophy.tech
Subject: Re: Deduciblity as knowledge (Re: Uncertainty in life)
Message-ID: <3993@sdcc3.ucsd.EDU>
Date: Fri, 29-May-87 03:57:54 EDT
Article-I.D.: sdcc3.3993
Posted: Fri May 29 03:57:54 1987
Date-Received: Sat, 30-May-87 10:21:47 EDT
References: <6762@mimsy.UUCP> <13261@watmath.UUCP> <3978@sdcc3.ucsd.EDU> <3722@jade.BERKELEY.EDU>
Reply-To: ma188saa@sdcc3.ucsd.edu.UUCP (Steve Bloch)
Organization: University of California, San Diego
Lines: 21
Keywords: Descartes, Proof theory, Theory of Knowledge

In article <3722@jade.BERKELEY.EDU> lagache@violet.berkeley.edu (Edouard Lagache) writes:
>In article <3978@sdcc3.ucsd.EDU> ma188saa@sdcc3.ucsd.edu.UUCP (Steve Bloch) writes:
>>>a contradiction is reached because we have taken as certain the hypothesis
>>>that nothing can be known for certain. Therefore, it must be so that you can
>>>know something for certain.
>>The truth of X does not imply that anybody KNOWS X.
>	It seems to be that the above argument misses the point of Descartes.
>	It is merely that X is true, but that he, Descartes, showed it to be
>	true.  If the mind deduce from things that are aleady known to a 
>	valid conclusion, then the nature of deduction allows you to "know"
>	the conclusion.

But X is not already known, it's assumed.  The assumption was
originally "Assume there is nothing that can be known for certain,"
NOT "Assume it is known for certain that nothing can be known for
certain," which would be obvious nonsense.  He, Descartes, did NOT
show X to be true (which would indeed give him the right to say it
was known), he showed (or tried to) something else UNDER THE
CONDITION that X was true.  The mere assumption that X is true
does not allow him to conclude (within the scope of the assumption)
that X is known for certain.  Or am I misunderstanding you?