Pragmatics for propositional attitudes
Maria Daria Aloni, Robert van Rooy, Martin Stokhof · 2001
Propositional attitude reports are analyzed in the framework of modal predicate logic (see [4]). Consider the following classical example from Quine which illustrates a difficulty arising for the standard version of this logic: (1) a. Philip believes that Cicero denounced Catiline. b. Philip does not believe that Tully denounced Catiline. c. Philip believes that x denounced Catiline. Suppose sentences (1a) and (1b) are true. What is the truth value of (1c) under the assignment that maps x to the individual d which is Cicero and Tully? As Quine observes, the ordinary notion of belief seems to require that although (1c) holds when x is specified in one way, namely as Cicero, it may yet fail when the same x is specified in some other way, namely as Tully. Classical modal predicate logic, in which variables are taken to range over plain individuals, fails to account for this ordinary sense of belief. In a possible world semantics, these ‘ways of specifying objects ’ can be characterized by means of the notion of an (individual) concept, i.e. a function from the