Abstract

Bradford Skow’s Objective Becoming (2015) is a strikingly original and philosophically rich contribution to contemporary philosophy of time. The book rewards very careful study, and is surely a ‘must-read’ for anyone with an interest in current debates concerning time and change. Perhaps the most immediately compelling aspect of the book is its leading question: if I [Skow] didn’t already accept the ‘block universe theory’ (BU),1 which theory of time would I defend? Skow’s surprising (and, from my perspective, welcome!) answer is that he would defend some version of the Moving Spotlight Theory (MST). However, Skow’s reason for this answer is less familiar: it is that MST—unlike BU and its popular rival Presentism—‘contains robust passage’. Skow goes on to (quite convincingly, in my view) defend two versions of MST against a number of common objections: ‘MST-Supertense’ and ‘MST-Time’. In the first part of this paper (§1), I investigate the question of what it is for a theory to contain robust passage in Skow’s sense. In particular, I argue that given Skow’s arguments in favour of robust passage, he should probably not count MST-Time as a theory that contains robust passage. I also argue that there are better reasons to reject BU than those Skow describes. In the second part of the paper (§2), I focus on Skow’s MST-Supertense. I argue that there are reasons for MSTers to reject MST-Supertense in favour of a more ‘traditional’ version of MST (the view I call ‘Classic MST’).