On one use of the term, "propositions" are objects of assertion, what successful uses of declarative sentences say. As such, they determine truth-values and truth conditions. On a second, they are the objects of certain psychological states (such as belief and wonder) ascribed with verbs that take sentential complements (such as believe and wonder). On a third use, they are what are (or could be) named by the complements of such verbs. Many assume that propositions in one sense are propositions in the others.

After some decades of skepticism about the worth of positing propositions, the last quarter of the twentieth century saw renewed interest in and vigorous debate over their nature. This can be traced in good part to three factors: the development in intensional logic of formal models of propositions; (not altogether unrelated) attacks on broadly Fregean accounts of propositions; and a spate of work on...