Showing papers on "Modal operator published in 1989"

Is Alethic Modal Logic Possible

Abstract: The title of my paper may appear paradoxical, misplaced, or even worse, out of date. The possibility of a reasonable modal logic was denied by Quine on philosophical grounds, but his objections have been dead for a while, even though they have not yet been completely buried.1 What has made a crucial difference is the development of what has generally been taken to be a viable semantics (model theory) for modal logic.2 This semantics has provided a basis from which Quine’s objections can apparently be answered satisfactorily and which yields a solid foundation for the different axiom systems for modal logic. Thus the question of the possibility of modal logic has apparently been disposed of for good, and my title question accordingly may seem pointless.

Quantified Modal Logic and the Plural De Re

Abstract: within a language whose only modal operators are the box and the diamond; other modal idioms cannot be expressed within such a language at all. Nonetheless, quantified modal logic has enjoyed considerable success in uncovering and explaining ambiguities in modal sentences and fallacies in modal reasoning. A prime example of this success is the now standard analysis of the distinction between modality de dido and modality de re. The analysis has been applied first and foremost to modal sentences containing definite descriptions. Such sentences are often ambiguous between an interpretation de dicto, according to which a modal property is attributed to a proposition (or, on some views, a sentence), and an interpretation de re, according to which a modal property is attributed to an individual. When these sentences are translated into the language of quantified modal logic, the de dicfo/de re ambiguity turns out to involve an ambiguity of scope. If the definite description is within the scope of the modal operator, then the operator attaches to a complete sentence, and the resulting sentence is de dicto. If the definite description is outside the scope of the modal operator, then the operator attaches to a predicate to form a modal predicate, and the resulting sentence is de re. Quantified modal logic has the resources to clarify and disambiguate English modal sentences containing definite descriptions. In this paper, I explore to what extent the analysis in terms of scope can be applied to modal sentences containing denoting phrases other than definite descriptions, phrases such as ‘some F’ and ‘every F.1 I will focus upon categorical modal sentences of the following two forms: mo s a1 idioms must be artificially restructured if they are to be expressed