Abstract

My dissertation develops a new approach to the semantics of modal languages. One of the central concerns is how we can adhere to a sensible ontology while retaining a semantical apparatus sufficiently rich for various modal languages and modal notions. In Chapter One, I argue that it is semantically desirable to quantify over concrete possible worlds and individuals and that David Lewis's genuine modal realism is nonetheless unacceptable especially for ontological reasons. In Chapters Two and Three, I propose and develop the view I call "Modal Quasi-Realism". On this view, various modal notions are analyzed in terms of a single primitive modal idiom: the modal quantifier 'There could have been'. In Chapter Four, I examine whether modal quasi-realism can provide a unified semantics for such various modal constructions as de re modal statements, modal comparatives, counterfactuals, and supervenience claims. Chapter Five considers how well various modal theories may fare as accounts of the notion of potential infinity. I show that only modal quasi-realism offers an adequate formulation of this notion. Chapter Six is devoted to the problem of modal epistemology. In this chapter, I argue that modal quasi-realism squares better with the central role of imagination in modal epistemology than competing modal theories. I present two independent arguments for modal quasi-realism in Chapter Seven. According to the first, modal quasi-realism need not introduce a dubious distinction between ordinary expressions. The other argument is based on the fact that the basic modal idiom of modal quasi-realism plays a central role in metalogical discourse. In Chapter Eight, I deal with the challenge that modal quasi-realism cannot offer sets of possibilia and hence, intensional objects. After suggesting two different ways in which the modal quasi-realist might be able to quantify over sets of possibilia, I propose two ways of handling the problem which do not rely on quantification over sets of possibilia. Stronger still, I argue that the relative lack of means for such quantification is beneficial for modal quasi-realism. I conclude, in Chapter Nine, with an exploration of the behavior of the modal quantifier in natural languages and in particular its interaction with the quantifier 'there is' as well as with definite descriptions