From a Modal Point of View: a Logical Investigation into Modalities De Dicto and De Re Paul Harrenstein Abstract: From a Modal Point of View: A Logical Investigation into Modalities De Dicto and De Re. Paul Harrenstein Philosophical conundrums regarding the reference of 'each man' in 'each man is mortal' in traditional logic were rendered irrelevant by the introduction of the quantifiers. In this paper comparable Fregean and Quinean issues concerning the reference of terms in modal contexts are bypassed in similar fashion by conceiving of modal operators as being capable of binding terms in their scope. Intensional phenomena such as the failure of substitution salva veritate of coreferential terms are then accounted for by pointing out that terms bound by a modal operator cannot be substituted. Moreover, the calamitous conclusion of an infamous argument due to Quine that modal distinctions are liable to collapse in quantified modal logics, is thus avoided in an elegant, be it somewhat unorthodox, way. (The more orthodox solution is to impose a division between referential terms, such as proper names and variables, on the one hand and general terms, which may describe the object they denote, on the other). These ideas constitute the philosophical background of the modal predicate logic PLuM, in which the formal investigations of the paper are executed. In the modal predicate logical languages for PLuM each modal operator is indexed with the terms it does not bind. The languages for PLuM will be semantically dealt with by interpreting them in a possible worlds framework. When a term is bound by a modal operator it will obtain a de dicto reading, otherwise it will get a de re reading. An axiomatization is provided for the most general system of PLuM. There are some striking resemblances between the semantics of PLuM and Kaplan's views on direct reference. In particular, the framework of PLuM offers prospects for a semantics for indexical referring expressions. These and related issues are dealt with in the penultimate chapter. The final chapter revolves around issues concerning quantification and other referential devices. The quantifiers behave in predicate logical structures in a similar fashion as a special kind of indexed modal operators do in a special class of possible world models. Accordingly, any quantified modal logic could be treated as a bi-modal logic. No miracles, however, are to be expected to result from this. The intention behind the development of PLuM, however, is rather to outline another way of doing modal predicate logic. The advantages of this approach are mainly of a philosophical nature:. Issues concerning the reference of terms in modal contexts are avoided. Moreover, one need no longer impose a once and for all division between referring and general terms.