May I quote you?

You (Brian Holtz) wrote at:

http://groups-beta.google.com/group/talk.philosophy.misc/msg/dfa50fbc7a2ce31?hl=en&lr=

<x-tad-bigger>...</x-tad-bigger>

<x-tad-bigger>Note that, while the Life thought experiment depends on mind being

computable, the logically possible universe (LPU) thought experiment

only assumes that our universe could be considered as a logically

possible sequence of (not necessarily finitely describable)

universe-states. The LPU hypothesis also depends on the thesis that

physicalism is right and that qualia and consciousness are

epiphenomena. The LPU hypothesis is of course unparsimonious (sort of

like the many-worlds interpretation of quantum theory), but parsimony

is perhaps inconsistent with *any* answer to the Big Why. </x-tad-bigger>

I'm afraid Physicalism is incompatible with Computationalism.

<x-tad-bigger> Marchal, B. (1988). Informatique théorique et philosophie de l'esprit. In </x-tad-bigger>

*<x-tad-bigger>Actes du 3ème colloque international de l'ARC</x-tad-bigger>*<x-tad-bigger>, pages 193-227, Toulouse.

Maudlin, T. (1989). Computation and Consciousness. </x-tad-bigger>

*<x-tad-bigger>The Journal of Philosophy</x-tad-bigger>*<x-tad-bigger>, pages 407-432.</x-tad-bigger>

With the computationalist assumption (comp), physics *must* be derived from a general measure definable by self-referential machines and defined on the collection of their "maximal consistent extensions". See my url for references. Sorry for being short. Note that this made comp empirically testable.

<x-tad-bigger>The idea that the world might be a dream is of course not new. But I

don't recall ever hearing that the world might be just a logically

possible dream for which no dreamer exists. </x-tad-bigger>

Sure. (But this does not make the dreamer "material" in any stronger sense that, if the dreamer observes itself, he will first discover some third person description of himself;(hopefully manageable with respect to its most probable history) and that by looking closely he will discover the "fuzziness" of "slumberland" (say) and its mathematics.

Do you know the Godel-Lob-Solovay provability/consistency modal logics G and G*?

They make possible to ask the machine about those questions (including the measure on the consistent extensions). Note that the machine remains mute on all deep questions (like "is there a world?"), but then G* can explain why. The difference between provable (G) and true (G*) allow to distinguish communicable knowledge (I guess quanta) and non communicable knowledge (I guess qualia).

For knowledge (and "first person notion") I use Theaetetus' definitions (Plato).

Smullyan's "Forever Undecided" is a recreative introduction to G. I guess you know Godel, but the basic fundamental papers are really:

<x-tad-bigger>

</x-tad-bigger><x-tad-bigger> Gödel, K. (1931). Über formal unentscheidbare sätze der principia mathematica und verwandter systeme i. </x-tad-bigger>

*<x-tad-bigger>Monatsh., Math. Phys.</x-tad-bigger>*<x-tad-bigger>, 38:173-198. Traduction américaine dans Davis 1965, page 5+.

Löb, M. H. (1955). Solution of a problem of Leon Henkin. </x-tad-bigger>

*<x-tad-bigger>Journal of Symbolic Logic</x-tad-bigger>*<x-tad-bigger>, 20:115-118.

Solovay, R. M. (1976). Provability Interpretation of Modal Logic. </x-tad-bigger>

*<x-tad-bigger>Israel Journal of Mathematics</x-tad-bigger>*<x-tad-bigger>, 25:287-304.</x-tad-bigger>

For the machine's interview you could read my currently last paper (and the errata perhaps):

http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHALAbstract.html

Bruno

http://iridia.ulb.ac.be/~marchal/