Re: possible worlds in logic.

Logic (and its possible worlds semantics)
says nothing (precise) about external reality.

Logic only says something about the relationship of
symbols in a formal language.

Remember that the reason non-sloppy mathematicians

use non-meaningful variable-names (i.e. terms) is

to avoid names that connote something in the world

and would lead one astray in understanding the precise

"formal" semantics of the mathematical formulae.

e.g. of problematic meaningful variable names:

one = 2.

two = 2.

four = 4.

therefore, one + two = four.

This strict "anonymous symbols" interpretation

is how one must treat formal logic and propositions

expressed in formal logic too. Every time

I read someone bemoaning how logic has difficulty with

expressing "what is going to happen in future", I think,

why would you expect a formal system of symbols to have

anything to do with future time in reality?

As far as I know, there is no good formulation of

a formal connection between a formal system and
""""""reality""""" <-unbalanced quotes, the secret

cause of asymmetry in the universe. How's that for a

"quining" paragraph?

Is there? For example, "truth" is defined in formal
logic with respect to, again, formal models with an infinite

number of formal symbols in them. It is not defined with respect

to some vague "correspondence" with external reality.

Someone was writing about "correspondence theory"

with this goal in mind many years back, and that sounded

interesting. I haven't read Tegemark et al. What do they say

about the formalities of how mathematics extends to
correspond to, or to be? external reality? To me, there is

still a huge disconnect there.

E.g. again, Godel's incompleteness

theorem is a theorem about the properties and limitations

of formal symbolic systems. The original theorem says nothing
whatsoever about reality itself, whatever that may "informally" be,

nor about the limitations of human minds, unless we take minds

to be theorem provers working on formal symbolic systems.

- Re: Possible Worlds, Logic, and MWI Hal Finney
- Re: Possible Worlds, Logic, and MWI Tim May
- Re: Possible Worlds, Logic, and MWI Tim May
- Re: Possible Worlds, Logic, and MWI Eric Hawthorne
- Re: Possible Worlds, Logic, and MWI Tim May
- Re: Possible Worlds, Logic, and MWI Eric Hawthorne
- Science Tim May
- Re: Science John M
- Re: Science Tim May
- Re: Science John M
- Re: Science Tim May
- RE: Science Ben Goertzel
- Re: Science Joao Leao
- Re: Science Russell Standish