What is McTaggart's central argument for the unreality of time, and what is the key tension he identifies in the A-series?
Think about your answer, then reveal below.
Model answer: McTaggart argues that genuine temporal change requires the A-series (past/present/future), but the A-series is contradictory: every event must have all three properties (past, present, future), yet these are mutually exclusive. Attempts to resolve this by saying events have the properties at different times generate an infinite regress.
McTaggart's argument is that the B-series (earlier/later) alone cannot account for change — it is a static ordering. But the A-series, which does capture change, contains a contradiction. Every event is past (from the future), present (now), and future (from the past), yet no event can simultaneously be all three. Saying 'it is future at earlier times and past at later times' just re-introduces the A-series at a higher level, generating an infinite regress.