The master argument of Diodorus Cronus as an alternative account of modality

Abstract

Modal Logic is the logic of necessity, possibility and impossibility. But twentieth century modal logic faced an epistemological problem: how we know the modal status of propositions. Diodorus Cronus, 3rd century BCE, offered an account of modality which avoids the epistemological problem by grounding modality in tense. His argument is plausible and justly famous, becoming known as The Master Argument of Diodorus. This paper uses a combination of modal and tense logics to identify the exact logic that the Master Argument commits us to.