# Re: Fitch's paradox and OWA

Date: Fri, 1 Jan 2010 01:51:12 -0800 (PST)

Message-ID: <c2eb97cc-c185-49b1-afe0-d37d90f13032_at_a21g2000yqc.googlegroups.com>

On 1 jan, 05:26, stevendaryl3..._at_yahoo.com (Daryl McCullough) wrote:

*> Marshall says...
**>
**> >However what I was referring to was specifically
**> >how they get from step 7 to step 8 within that
**> >RAA proof. Your response does not seem to
**> >address that particular issue.
**>
**> That's exactly the step that I was talking about.
**> Steps (4), (5) and (6) and (7) constitute a proof
**> of ~K(p ∧ ~Kp). Therefore, we have
**> |- ~K(p ∧ ~Kp)
**>
**> By C, if you have |- f, then you have |- [] f.
**> Letting f = ~K(p ∧ ~Kp), it follows that
**> |- [] ~K(p ∧ ~Kp)
**> which is step (8).
**>
**> >Are your comfortable with how step 8 is
**> >obtained from step 7 via Rule C as described
**> >on this page?
**> >http://plato.stanford.edu/entries/fitch-paradox/
**>
**> Yes, that's exactly what they are doing. They
**> didn't use the |- symbol in step 7, but it is
**> clear that (7) is the conclusion of a proof.
*

Wow. You are right. They correctly conclude in (7) that |- ~K(p ∧ ~Kp).

Hmm. I need to think this over. I'm beginning to believe now that the inference in the paradox is in fact correct.

- Jan Hidders