  Although not undisputed, some standard differences between events and physical objects are commonplace in the philosophical literature. First, there would seem to be a difference in mode of being: material objects such as stones and chairs are said to exist; events are said to occur or happen or take place (Hacker 1982a; Cresswell 1986). Second, there would seem to be differences in the way objects and events relate to space and time. Ordinary objects are supposed to have relatively crisp spatial boundaries and vague temporal boundaries; events, by contrast, would have relatively vague spatial boundaries and crisp temporal boundaries.  Objects are said to be invidiously located in space—they occupy their spatial location; events tolerate co-location much more easily (Quinton 1979; Hacker 1982b). Objects can move; events cannot (Dretske 1967). Finally, objects are standardly construed as enduring continuants—they are in time and persist through time by being wholly present at every time at which they exist; events are perduring occurrents—they take up time and persist by having different parts or “stages” at different times (Johnson 1921; Mellor 1980; Simons 2000).