[FOM] Is Godel's Theorem surprising?

[Harvey Friedman]

On 12/10/06 9:19 AM, "Charles Silver" <silver_1 at mindspring.com> wrote:

> First, thanks very much for all the interesting  and enlightening
> responses to my question.   A couple of comments:
> Diagonalization is not central to Godel's (first) theorem, as shown
> by Kripke's proof of G's theorem that was published by Putnam, which
> does not *require* diagonalization.
> I believe this proof also shows--please correct me if I'm wrong--
> that a specifically *mathematical* proposition (though an unusual
> one) cannot be proved nor can its negation.
> 
> 

It would be helpful to the FOM readership for you to give us a reference to
this paper by Putnam. I have serious doubts about the claims you are
suggesting.

Harvey Friedman