Reichenbach, Prior and hybrid tense logic

Patrick Blackburn, Klaus Frovin Jørgensen
2015 Synthese  
In this paper we argue that Prior and Reichenbach are best viewed as allies, not antagonists. We do so by combining the central insights of Prior and Reichenbach in the framework of hybrid tense logic. This overcomes a well-known defect of Reichenbach's tense schema, namely that it gives multiple representations to sentences in the future perfect and the future-in-the-past. It also makes it easy to define an iterative schema for tense that allows for multiple points of reference, a possibility
more » ... oted by Prior and demanded by Comrie, and we sketch how this schema can be generalized to a shift-and-restrict pattern in which special propositional symbols (for adverbials and indexicals) act as restrictors on the range of tense operators. Keywords Arthur Prior · Hans Reichenbach · point of reference · hybrid logic Introduction Arthur Prior's Past, Present and Future (Prior 1967), henceforth PPF, contains the first detailed work on hybrid logic, an extension of ordinary tense logic which allows reference to times using special propositional symbols. That Prior was the inventor of tense logic is well known; that he was also the inventor of hybrid logic is not. Nonetheless, hybrid logic plays a clear (if somewhat restricted) role in Prior's best
doi:10.1007/s11229-015-0920-0 fatcat:3bekiznlcjcpvden6clcpujbh4