Re: Fitch's paradox and OWA

From: Daniel Pitts <>
Date: Wed, 16 Dec 2009 10:48:20 -0800
Message-ID: <SAcWm.47926$cd7.43151_at_newsfe04.iad>

Nilone wrote:
> Does Fitch's paradox prove an inherent contradiction in the open-world
> assumption?
I had never heard of Fitch's paradox, but it sounds a like Gödel has disproved it somewhat with his theorem.

Gödel theorem proves that in any system of sufficient reasoning power, there are truths about the system which can not be derived from within the system. There is no contradiction, unless your truths somehow include "all truths are provable", which is close to what Fitch has said.

Actually, it could be that Fitch simply proved that a knowable truth is knowable, when he intended to prove something else.

Daniel Pitts' Tech Blog: <>
Received on Wed Dec 16 2009 - 19:48:20 CET

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