[FOM] Nik Weaver's conceptualism and the correctness of the Schu"tte-Feferman analysis

Nik Weaver nweaver at math.wustl.edu
Wed Apr 5 14:01:38 EDT 2006

Aatu Koskensilta wrote:

> First, there's a "general difficulty" Weaver mentions. I think
> this issue is largely a red herring, but I'll say something
> about it just to put it to rest.

Was this message truncated?  I don't see where the "general
difficulty" was in fact put to rest.  A (correct) point is made
about this sort of difficulty in general, the author acknowledges
that it doesn't address my specific argument and promises to do
so, then the message peters out in a general discussion of the
concept of predicativism.

Aatu, are you waiting for me to accept your informal picture of
predicativism before telling us why I'm wrong?  If so, go ahead
--- it looked basically reasonable to me.

One other thing.  If you really want to decisively defeat my
objection, it might help to look at my paper and see exactly what
I say.  Don't take this the wrong way --- your understanding of my
basic position seems correct --- but it is fairly obvious (on the
basis of your current message and an earlier one that wasn't posted)
that you've looked at Feferman's response to my paper and my response
to Feferman, but you haven't looked at the paper itself.  You might
find that my case is more solid than you think.

After you successfully refute the "general difficulty", I look
forward to seeing your refutation of my other basic point, the
induction versus recursion problem.  I identified a number of
other difficulties in various proposed formal systems for
predicativism, but those are the main two on which I think my
critique should stand or fall.


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