1. The document discusses John McTaggart's theories on time, known as the A-theory and B-theory of time. The A-theory views time as events being in the past, present or future, while the B-theory views time as events being earlier or later than one another.
2. McTaggart ultimately argued that neither theory provides an accurate explanation of time, and that if time cannot be explained by either theory, then time does not truly exist.
3. The document also discusses the views of presentism and eternalism. Presentism holds that only the present is real, while eternalism views past, present and future as all equally real.