FOM: Books, foundations, intuitionism, NF

[wtait@ix.netcom.com]

Vaughan Pratt wrote <pratt at cs.Stanford.EDU>
>Š now do not see how you infer from
>the quotation rejection by Goedel of *any* aspect of intuitionism.
>(My previous objection to your attribution to Goedel of such rejection
>was the weaker one that Goedel at least did not reject the semantic
>content of intuitionism.)

I don't know about *any* aspect; but Goedel did reject something that he believed to be a presupposition of intuitionistic logic, and that is the absolute notion of proof. (See his unpublished papers *1933o and *1938a in Volume III.) [I actually think that he was wrong here and that intuitionism no more presupposes the absoute notion of proof than his interpretation of arithmetic using functionals of higher type presupposes the absolute notion of function of a given type.]

Bill Tait