Re: The role of logic, & planning ...

From: Russell Standish <R.Standish.domain.name.hidden>
Date: Wed, 2 May 2001 09:57:07 +1000 (EST)

I don't think Bruno's conclusion is weird. I come to essentially the
same conclusion in "Occam", without the need for formalising
"Knowledge", nor the need to use Modal logic. Of course I do use logic
of the ordinary kind - I would be surprised if anyone could do away
with it altogether.

I would like to think that my exposition is easier to follow than
Bruno's, but this could simply be a biased viewpoint on my part. I
welcome comment and criticism on that paper.

Incidently, I didn't mean to imply that this sort of modeling of
Knowlegde was inappropriate, only that there was no discussion as to
why one would want to model it in this particular way. Its really the
same as when Hal Ruhl (and I admit I'm putting words in his mouth
here, although its consistent with my understanding of his position)
models the universe by cellular automata. Yes I can agree its a
consistent model, and possibly one that's testable. However, I fail to
see why one would want to do that. Good physical models ought to have
some understandable basis (explanatory power perhaps).

I notice Bruno has posted a more detailed discourse on this issue,
which I will digest in due course. Perhaps all he was doing was
assuming a cultural background of philosophy I have not been exposed
to. Just as an example, he says most philosophers would agree that
[]A->A, where []A is interpreted as knowing A. This is clearly a
different meaning of the word "to know" that we use here in
Australia. I know of plenty of people who know that God exists. And I
know of a number of other people who know that God doesn't exist. So,
by this application of Modal logic, we can conclude that God both
exists and doesn't exist at the same time, which seems kind of illogical.

Perhaps the way out of this mess is to say that I'me really talking
about belief, rather than knowledge, however that would imply that
knowledge is devoid of meaning, since it is impossible to establish
with certainty whether any particular fact is true. Even Mathematical
proof is contingent upon belief of the efficacy of the formal proof,
something that has been called into doubt, particularly for more
complex proofs like Fermat's last theorem, or the 4 colour theorem.

I don't mean to be picky, but its just these sorts of considerations
and misunderstandings that throw me off the track every time.

                                                Cheers

George Levy wrote:
>
>
>
> Russell Standish wrote:
>
> > However, my main problem with Bruno's work lay not in the technical
> > details of Model logic, rather with the phrases of the ilk "We
> > modelise knowledge by Bew(|p|)". I can appreciate its only a model,
> > but why should I believe that model of knowing has any connection with
> > reality? I'm afraid none of the Booloses, nor Bruno's posting helped
> > me with this.
>
> Hi Russell,
>
> I guess the discussion is moving to the meta level. The question is not what the
> model is, but what format the model should be. Using logic as a vehicle seems to
> me to be a meritorious approach, especially if he can derive physical effects
> form pure logic.... He won't be the first. Boltzmann and Darwin have done it
> before him. Bruno's suggestion that "physics is a branch of machine psychology"
> is unfamiliar and surprising... arguably as wierd as some of the stuff I came up
> with...
>
> If logic (or some form of logical model) is not the vehicle for describing
> reality, then what is?
>
> George
>



----------------------------------------------------------------------------
Dr. Russell Standish Director
High Performance Computing Support Unit, Phone 9385 6967
UNSW SYDNEY 2052 Fax 9385 6965
Australia R.Standish.domain.name.hidden
Room 2075, Red Centre http://parallel.hpc.unsw.edu.au/rks
----------------------------------------------------------------------------
Received on Tue May 01 2001 - 17:27:06 PDT

This archive was generated by hypermail 2.3.0 : Fri Feb 16 2018 - 13:20:07 PST