Meta Ontology

So far, T\texttimesW frames have been employed to provide a semanticsfor a language of tense logic that includes a modal operator thatexpresses historical necessity. The operator is defined in terms of quantificationover possible courses of events that satisfy a certain constraint,namely, that of being alike up to a given point. However, a modal operatorcan as well be defined without placing that constraint. This paper outlinesa T\texttimesW logic where an operator of the latter kind is used to expressthe epistemic property of definiteness. Section 1 provides the theoreticalbackground. Sections 2 and 3 set out the semantics. Sections 4 and 5show, drawing on established results, that there is a sound and completeaxiomatization of the logic outlined.