Monday, 1 September 2014

Projections Of Ideas And Intensional (& Epistemic) Logic

Halliday & Matthiessen (1999: 112):
Projections of ideas have played a special rôle in the extension of standard logic within intensional logic (or more restrictedly for knowing and believing, within epistemic logic) to allow for reasoning in this domain. One of the features of the projection of ideas that has received special attention in logically-oriented approaches to meaning is its “referential opacity”.   If a speaker knows that Henry is the king, and construes someone else’s belief as Thomas thinks Henry is a nice man, the referring expression Henry cannot be replaced by the king although the speaker knows they have the same referent: ‘Thomas thinks Henry is a nice man’ cannot be inferred from ‘Thomas thinks Henry is a nice man’ since the identity of Henry and the king has not been established in the projected world of Thomas’s consciousness.