One of the
things we tried to do in the hook was to be very explicit about the
difference between our theoretical account of statements, propositions
and truth, and our mathematical models of these things. ... we
developed set-theoretic models of the key notions involved, much in the
way an orrery is a model of, but not a theory of, the motion of
the planets.
We ... think it is the right way to
understand the pervasive use of set theory in formal semantics. ... we
explicitly confronted issues about whether some aspect of the model
was a reflection of the domain modeled or, rather, an artifact of the
way we chose to model it. The wires that hold the orrery's spheres do
not commit its designer to any claim about what holds the planets in
place. Similarly, we have seen many features of our set-theoretic models
that do not reflect theoretical commitments about the nature of the
semantic objects modeled.
-- Jon Barwise, John Etchemendy. The
Liar, pp193-4. 1987