Global safety

how to deal with necessary truths

Jaakko Hirvelä

pp. 1167-1186

in: Simon Lohse, Karim Bschir, Hasok Chang (eds), Systematicity, Synthese 196 (3), 2019.

Abstract

According to the safety condition, a subject knows that p only if she would believe that p only if p was true. The safety condition has been a very popular necessary condition for knowledge of late. However, it is well documented that the safety condition is trivially satisfied in cases where the subject believes in a necessary truth. This is for the simple reason that a necessary truth is true in all possible worlds, and therefore it is true in all possible worlds where it is believed. But clearly, all beliefs concerning necessary truths do not amount to knowledge. The safety theorists have attempted to deal with the problem caused by necessary truths by restricting the safety condition to purely contingent truths and by globalizing the safety condition to a set of propositions. Both of these solutions are problematic. The principal aim of this paper is to develop a version of the safety condition that is able to deal with cases featuring necessary truths.