Abstract: Aristotle believes that some things are not in time; that the things that are in time are all and only those things that last for a finite length of time. This raises a puzzle. Everlasting things are (on this view) not in time. However, Aristotle thinks that some of the things that last forever move. This chapter presents a solution to this puzzle. It argues that everlasting movements are part of the temporal order: they have parts that are simultaneous with, or before or after, other changes. However, there is a sense in which things that last forever are not in time. Time does not cause them to grow older or decay. Aristotle’s view of being in time is compared to a view that can be found in Plato. The sense in which (on Aristotle’s account) time is a cause is explained.

Keywords: being in time, everlasting movements, everlasting things, Plato, cause, decay, growing older,