Re: SUO: Re: RE: Logic and Ontology
I still don't get it ... sorry for being so obtuse :(
From: "John F. Sowa" <sowa@bestweb.net>
> In that case, there is one fixed universe of discourse, and
> a predicate such as P(x) is true of some object x if and only if
> x happens to be a member of the set of things for which P is true.
Well for any given time in any given context (real, imaginary, or
hypothetical) in which we deem that the predicate holds, then (P x) will be
just as good as (member x P). Will it not?
> However, if you are talking about hypothetical things, plans for
> the future, or comparisons of the state of the world at different
> points in time, then the distinction is very important.
>
> For example, let the predicate P(x) mean "x is a Boeing 777 airplane".
>
> Today, the set of all x's for which P(x) is true is an existing
> set of things in the world. But for many years, engineers at Boeing
> were talking about (and defining) the predicate P when no such
> things existed. They were happily defining the predicate P (in terms
> of computerized diagrams, simulations, etc.) even though the actual
> set was empty.
You seem to have switched the context of the model but kept the same context
for the world. In Boeing's design world the set was *not* empty.
Seth Russell