Statements about Events Modal and Tense Analysis in Medieval Logic

Prior on the semantics of modal and tense logic

In celebrating Arthur Prior we celebrate what he gave to the world. Much of this is measured by what others have made of his ideas after his death, and it is right that this should be so, since a philosopher’s greatness is marked by his legacy. My focus however will be a little different. I want in this talk to look at what Prior himself thought he was accomplishing. In particular I want to inv...

Modal Realism with Modal Tense

Modal realists should fashion their theory by postulating and taking seriously the modal equivalent of tense, or modal tense. This will give them a uniform way to respond to five different objections, one each by Skyrms, Quine, and Peacocke, and two by van Inwagen, and suggest a non-Lewisian path to modal realism. 0. Introduction The extensive parallel between temporal logic and modal logic has...

Reasoning about local properties in modal logic

In modal logic, when adding a syntactic property to an axiomatisation, this property will semantically become true in all models, in all situations, under all circumstances. For instance, adding a property like Kap→ Kbp (agent b knows at least what agent a knows) to an axiomatisation of some epistemic logic has as an effect that such a property becomes globally true, i.e., it will hold in all s...

On the Modal Logic of Subset and Superset: Tense Logic over Medvedev Frames

Viewing the language of modal logic as a language for describing directed graphs, a natural type of directed graph to study modally is one where the nodes are sets and the edge relation is the subset or superset relation. A well-known example from the literature on intuitionistic logic is the class of Medvedev frames hW,Ri where W is the set of nonempty subsets of some nonempty finite set S, an...

Lecture 2 : Time , tense , and tense - logic ∗