🚀 go-pugleaf

In article <1992Oct8.050325.22915@guinness.idbsu.edu> holmes@opal.idbsu.edu (Randall Holmes) writes:
>The reason why I maintain that alternate physical universes exist is
>that I also maintain that the physical world is a "mathematical
>object" (say, for the sake of argument, a function with domain R^{4}
>and values expressing the intensities of various fields at given
>places and times; I am not committed to a specific description of this
>kind).  

Zur\"uck zu Pythagoras!  As I recall, Quine suggested a similar idea
some years ago, but I can't remember where; "Ontological Relativity"
maybe.  Pythagoreanism notwithstanding, I take it you don't think the
physical world is *literally* a mathematical object, if only for the
fact that, as you yourself hint, any number of other mathematical
objects would have served just as well.

>There are, of course, many other functions of the same general
>kind as the one to be identified with the physical universe, some of
>which satisfy the same "natural laws" as ours.  These latter ones are
>the "possible worlds" to which I am referring.

Seems to me that, on this story alone, there is no basis for saying
that one of these alternative functions satisfies the same natural
laws as ours, since those functions only describe what actually
happens in fact in those worlds.  To say that certain natural laws
obtain you have to be able to say that those worlds support certain
sorts of couterfactuals, i.e., relative to those worlds you have to be
able to be able to talk about what *would* happen under certain
conditions, and for this you need at least some notion of "closeness"
or "similarity" of worlds a la Robert Stalnaker or David Lewis for
understanding counterfactual discourse.  (E.g., p counterfactually
implies q iff q is true in the closest world in which p is true.)
Even this though is rather uncomfortably Humean for us gonzo realists.

>The opinions expressed		|     --Sincerely,
>above are not the "official"	|     M. Randall Holmes
>opinions of any person		|     Math. Dept., Boise State Univ.
>or institution.			|     holmes@opal.idbsu.edu

--Chris Menzel
  Philosophy Department
  Texas A&M University