The Two Main Concepts of Events in Time
An event is something that happens. More precisely, an event is something that happens at a time. Events can be something explicit, involving things, for example, events such as your birthday, your exams, the death of the sun.
Figure 2.1 The A-Series
In this conception of events, time defines events. Events do not define time. McTaggart argues that events are defined by time in an important way. Events occupy positions in a time series. We typically conceive of events in one of two time series. McTaggart calls these the А-series and the B-series.
Figure 2.1 depicts events in the A-series. E is in the far future and F is in the recent past. There is also a single moment in which neither event lies, the present.
The A-series is the series of times that run from the past, through the present, to the future. It includes more specific positions such the near future, the fat- future, the recent past, and the distant past. It also includes more specific times such as a million years ago, last week, this year, and next Tuesday.
The main feature of the A-series is that events in it are either positioned in the past, present, or future, or are some determinate of those temporal positions. For example, an event can happen a million years ago or yesterday (determinates of the determinable past)-, an event can be past or future (determinates of time).
The В-series is the time series of events in which events are earlier, later, or simultaneous with each other. For example, in Figure 2.2, G is later than E, E, is simultaneous with E, and F is earlier than E.
We can also derive A-series positions from their relative positions in the В-series. For example, G is later than Er As such, we can derive an A-series position for G and F relative to Et; relative to Ep G is in the future; relative to F, G is in the past.
However, some philosophers object that such a derived A-series is not enough for any real A-series position. A real A-series position is special; it is not merely
Figure 2.2 The B-Series
derived from any В-series; it is fundamental in a way that past, present, and future positions defined relative to В-series positions are not. The В-series is derived from the real А-series, not the other way around.
In contrast, other philosophers argue that all А-series positions are derived from В-series positions (or something similar). They argue that, if the A-series is fundamental, then it is impossible to escape what is known as McTaggart’s Paradox. If this paradox holds, then there can be no real change, time, and so no real А-series at all.