Abstract
Some twenty years ago, semanticists of natural language came to be overwhelmed by the
problem of semantic analysis of belief sentences (and sentences reporting other kinds of
propositional attitudes): the trouble was that sentences of the shapes X believes that A and X
believes that B appeared to be able to have different truth values even in cases when A and B
shared the same intension, i.e. were, from the viewpoint of intensional semantics,
synonymous
1
. Thus, taking intensional semantics for granted, belief sentences appeared to
violate the principle of intersubstitutivity of synonyms. The verdict of the gurus of intensional
semantics was that hence intensional semantics is inadequate, or at least insufficient for the
purposes of analysis of propositional attitudes; and that we need a kind of a ‘hyperintensional
semantics’.