Knowing who occupies an office: purely contingent, necessary and impossible offices

Abstract

This paper examines different kinds of definite descriptions denoting purely contingent, necessary or impossible objects. The discourse about contingent/impossible/necessary objects can be organised in terms of rational questions to ask and answer relative to the modal profile of the entity in question. There are also limits on what it is rational to know about entities with this or that modal profile. We will also examine epistemic modalities; they are the kind of necessity and possibility that is determined by epistemic constraints related to knowledge or rationality. Definite descriptions denote so-called offices, roles, or things to be. We explicate these alpha-offices as partial functions from possible worlds to chronologies of objects of type alpha, where alpha is mostly the type of individuals. Our starting point is Prior's distinction between a 'weak' and 'strong' definite article 'the'. In both cases, the definite description refers to at most one object; yet, in the case of the weak 'the', the referred object can change over time, while in the case of the strong 'the', the object referred to by the definite description is the same forever, once the office has been occupied. The main result we present is the way how to obtain a Wh-knowledge about who or what plays a given role presented by a hyper-office, i.e. procedure producing an office. Another no less important result concerns the epistemic necessity of the impossibility of knowing who or what occupies the impossible office presented by a hyper-office.