 Existence in time is a major topic in the philosophy of time. Usually, objects come into being at one point in time and go out of being at some later time. But what is it for an object to exist in time? Do only present objects exist, as a presentist would have it, or is existence to be understood in a broader sense comprising past and future objects as well, as an eternalist would hold? The controversy between presentism and eternalism is accompanied by a debate on persistence, that is, on the question how objects exist through time. Are objects wholly present at each instant at which they exist — a view known as endurantism — or do they persist by having different temporal stages at different instants in time — a view called perdurantism? For a detailed overview of these debates, see e.g. Dyke and Bardon (2013), Meyer (2013), as well as the entries on  time,  temporal parts, and  identity over time.