 According to Leftow, there can be no change in (timeless) eternity, and in eternity, all events happen (A-) simultaneously. However, in some places eternity is instead described as involving succession, namely as consisting of a number of different B-series corresponding to different temporal reference frames (Leftow 1991: 239). Prima facie, these are different, incompatible ideas. B-theorists, who hold that time, fundamentally, consists of events standing in B-relations of precedence and simultaneity, do not also hold that all of time collapses to a single time.