W ramach seminarium Myślenie i język we współczesnej filozofii amerykańskiej i brytyjskiej, prowadzonego przez członka OBF, Tadeusza Ciecierskiego, dnia 20 listopada 2006 o godzinie 17:15 w sali 23 (bud. 1224 OBTA), przedstawiony zostanie referat Rona Chrisleya Model-theoretic semantics for bivalent, realist logics that reject the law of the excluded middle.
Conventional wisdom has it that rejecting the law of excluded middle is
part of a package that also includes rejecting bivalence and embracing
semantic anti-realism. I wish to consider a model-theoretic semantics
for first order predicate logic that rejects the classical semantic
axiom for negation (“not-S is true in M iff it is not the case that S is
true in M”), but supports both bivalence and semantic realism. That is,
for all models M and all sentences S it is the case that either S is
true in M or S is false in M; and it does not follow from the definition
of truth in a model that if S is true in M then there must be a proof of
S in M. If there is time, I will give some possible applications of
this logic (e.g., as a way of steering a middle course between Fregean
and Russellian accounts of empty singular terms). As logic is not my
area of specialization, I am especially open to criticism and suggestions.