On Logic (was Use of the Extropian Principles)

From: Lee Corbin (lcorbin@tsoft.com)
Date: Sat May 25 2002 - 09:45:53 MDT


Giu1i0 Prisc0 writes

> Or perhaps a overestimation of the power of logic. I recall that the
> discussion started when the Principles were used in support of statements
> that just did not feel right to others. I think we have to live with this:
> perhaps no thinking system can be so watertight to imply all statements that
> one "likes" and exclude all statements that one does not like (there are
> analogies in mathematical logic e.g. the Godel proof).

Yes, I agree with every phrase of your paragraph. But what do we mean by
logic, exactly? I think that you're right because I believe that what we
should mean by "logic" plays---and should play---almost no role in our
discussions. I know that that sounds funny, but read on.

> I am convinced of the importance of rational and analytic system
> thinking

Yes indeed!

> but believe that, at times, basic gut feelings on what is right
> or wrong may be a better guide.

Quite right. One has to be very careful with logic. Consider
the following theorem:

Theorem: God Exists.

Proof: If this sentence is true, then God exists. Therefore,
God exists because that sentence is indeed true. How do we
know that it's true? Simple. A sentence is true when the claim
that it makes is correct (or true). Well, what claim does that
sentence make? It claims that if it itself were true, then God
would exist. But that's so! If indeed the sentence were true,
then God would exist. Since what the sentence claims is so, then
the sentence is true, and so God exists. Q.E.D.

There is *no* logical flaw in the above proof, despite the
frenzied attempts it will provoke to find a flaw. The flaw
in the proof is semantical, not logical. It turns out that
words cannot always be thrown around with impunity---careful
thought and good judgment are always necessary.

Lee



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