Abstract

Philosophical logic has its problem-children; and among these the Principle of Substitutivity of codesignating expressions — the linguistic spawn of Leibniz's law—has achieved a place of prominence. It has become increasingly apparent that a certain style of linguistic analysis, which seeks to impose formal regimentation ruled by the constraints of classical quantification theory, does not yield results with the kind of uniformity and elegance one should hope for from a satisfyi.ng theory. The root of the difficulty, I believe, bears upon the answers to fundamental questions concerning the nature of cognitive agents and the purposes which their use of language is designed to further. If this is the case, one might expect to find some of the trouble surfacing at precisely those points where the language is used to convey information about the cognitive activities associated with the use of language by such agents. So it is.The central problem of this essay is the interpretation of referential expressions in statements involving propositional attitudes, with the focus on belief contexts. But I shall begin by placing the discussion within a broader theoretical framework.