A-Time, B-Time

In his introduction, Ganssle provides a lucid description of McTaggert’s A and B series (or theories) of time: “The B-theory holds that the most important thing about locating events in time is their relation to other events. So something happens before, after or at the same time as something else. The A-theory does not deny that events stand in these relations, but it holds that the more important thing about events is that some are in the past, some are in the future, and some are happening now.” A-theorists believe that past, present and future cannot be explained in terms of before, simultaneous, and after because attempting to do so ignores the priority of “the reality of the Now.”

According to the A-theorist, “the Now exists in a way that the past and future do not,” while for the B-theorist, “the Now is dependent on the psychological states of knowing minds.” Without conscious minds, there would be no Now. By down-grading the Now to a state of mind, the B-theorist also is claiming that each moment is as real as every other: “Take a particular event, such as the event of a particular elephant taking a drink of water 141 years ago. Most A-theorists will hold that this event does not exist. It is not real. It did exist (141 years ago), but it no longer does. The B-theorist will believe that the event in question is real. It does exist. It exists now even if it is not occurring now. It occurred 141 years ago.” For many philosophers, God can be timeless only if the B-theory is true, since only then do past and future events exist for God to know or be related to.