The Unreality of Time

"The Unreality of Time" is the best-known philosophical work of the Cambridge idealist J. M. E. McTaggart. In the paper, first published in 1908 in Mind 17: 457-73, McTaggart argues that time is unreal because our descriptions of time are either contradictory, circular, or insufficient. To frame his argument, McTaggart identifies two descriptions of time, which he calls the A-series and the B-series. The A-series identifies positions in time as past, present, or future; the B-series, as earlier than or later than some time position. Attacking the A-series, McTaggart argues that any event in the A-series is past, present, and future, which is contradictory in that each of those properties excludes the other two. He further urges that describing an event as past, present or future at different times is circular because we would need to describe those "different times" again by past, present, or future, and then again describe that description by past, present, or future, and so on. Attacking the B-series, McTaggart argues that time involves change, but because earlier-later relationships never change (e.g. the year 2010 is always later than 2000), the B-series must be an inadequate account of time.