Abstract
We define Denial Logic DL, a system of justification logic that models an
agent whose justified beliefs are false, who cannot avow his own propositional
attitudes and who can believe contradictions but not tautologies of classical
propositional logic. Using Artemov's natural semantics for justification logic
JL, in which justifications are interpreted as sets of formulas, we provide an
inductive construction of models of DL, and prove soundness and completeness
results for DL. Some logical notions developed for JL, such as constant
specifications and the internalization property, are inconsistent with DL. This
leads us to define negative constant specifications for DL, which can be used
to model agents with justified false beliefs. Denial logic can therefore be
relevant to philosophical skepticism. We use DL with what we call coherent
negative constant specifications to model a Putnamian brain in a vat with the
justified false belief that it is not a brain in a vat, and derive a model of
JL in which "I am a brain in a vat" is false. We define the fusion of Denial
Logic with the Logic of Proofs to model an agent who can justify and check
tautologies and who can believe his justified false beliefs. Denial Logic was
inspired by the contemporary debate over anthropogenic global warming.
Users
Please
log in to take part in the discussion (add own reviews or comments).