X-Message-Number: 10225
Date: Thu, 13 Aug 1998 11:27:36 EDT
Subject: Goedel, Liar, Barber

Since the relevance to cryonics is somewhat tenuous, and because of time
limitations, I'll try to keep it brief; but since evidently a fair number of
people on Cryonet are interested, I won't skip it altogether.

Thomas Donaldson (#10217) mentions the Barber "paradox," which is entirely
different from the Liar, and much easier, as follows:

In some town (not Seville) there is one barber, and the barber shaves all
those men who don't shave themselves. Who shaves the barber?

Obviously, no problem arises except in the case of the barber himself, so the
statement essentially reduces to: "If the barber shaves himself, then he does
not shave himself; and if he does not shave himself, then he does shave
himself." This is merely self-contradiction, not paradox in any sense.
Childishly simple, with no shades of Goedel whatever.  

Thomas' remarks about neural nets etc. are interesting, but open up much too
large an area for me to pursue here.

Timur Rozenfeld (#10218) appears to agree with me about the humor of using
rationality to disprove the value of rationality, although his wording didn't
make it clear whether "On the contrary" referred to my statement or Simberg's.

Rand Simberg (#10220) writes, "If your most fundamental goal is to get into a
Christian heaven, science and rationality do nothing to aid you in that." But
heaven cannot be a fundamental goal; "fundamental" in my lexicon means built
in by biology, essentially shared by everyone in a certain sense.

Peter Merel (#10221) points out that questioning Goedel and other eminences is
presumptuous. The full technical "reasoned argument" that he reasonably
requests is not yet in satisfactory form--it's very difficult to make it clear
enough--but I can repeat an easily understood clue or two. Goedel himself said
his theorem is analogous to the Liar (Epimenides etc.) "paradox," and the
latter, while still in dispute, was deflated not only by little old me, but by
many others long ago, including Aristotle. The sentence "This statement is
false." is not a proposition, because it is essentially meaningless--there is
no root referent. I know, there is no agreement on what constitutes a
"proposition," but surely anyone can see at least the possibility that
Aristotle and I are right, which opens up at least the possibility that
Goedel's conclusion was wrong.

Robert Ettinger
Cryonics Institute
Immortalist Society

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