Published online by Cambridge University Press: 05 June 2012
Saul Kripke, ‘A Puzzle about Belief’, in A. Margalit, ed., Meaning and Use (Dordrecht: Reidel, 1979), pp. 239–83; Donald Davidson, ‘On Saying That’, in his Inquiries into Truth and Interpretation (Oxford: Oxford University Press, 1984), pp. 93–108.
Semantics is the attempt to give a systematic explanation of how the meaning of sentences depends upon the meaning of their parts. Modern semantics began with Frege, whose logical system depends on the semantics of the sentences which can be constructed using its grammar. Frege's semantics was extensional: in general, whole sentences may be swapped when they have the same truth-value, singular terms may be swapped when they refer to the same object, and predicates may be swapped when they're true of the same things.
Propositional-attitude constructions – constructions involving a psychological verb (‘believes’, ‘hopes’, ‘wishes’, ‘fears’, etc.) and a ‘that’-clause – have presented a challenge to extensionalism from the beginning. It's clear that more matters about sentences which occur in such ‘that’-clauses than their truth-value, and it seems that more matters about singular terms which occur here than which object they refer to, and about predicates than which things they're true of. How, then, are we to explain what the words are doing in these ‘that’-clauses? How can we provide a semantics for propositional-attitude constructions?