event anything that happens; an occurrence. Two fundamental questions about events, which philosophers have usually treated together, are: (1) Are there events?, and (2) If so, what is their nature? Some philosophers simply assume that there are events. Others argue for that, typically through finding semantic theories for ordinary claims that apparently concern the fact that some agent has done something or that some thing has changed. Most philosophers presume that the events whose existence is proved by such arguments are abstract particulars, ‘particulars’ in the sense that they are non-repeatable and spatially locatable, ‘abstract’ in the sense that more than one event can occur simultaneously in the same place. The theories of events espoused by Davidson (in his causal view), Kim (though his view may be unstable in this respect), Jonathan Bennett, and Lawrence Lombard take them to be abstract particulars. However, Chisholm takes events to be abstract universals; and Quine and Davidson (in his later view) take them to be concrete particulars. Some philosophers who think of events as abstract particulars tend to associate the concept of an event with the concept of change; an event is a change in some object or other (though some philosophers have doubts about this and others have denied it outright). The time at which an event, construed as a particular, occurs can be associated with the (shortest) time at which the object, which is the subject of that event, changes from the having of one property to the having of another, contrary property. Events inherit whatever spatial locations they have from the spatial locations, if any, of the things that those events are changes in. Thus, an event that is a change in an object, x, from being F to being G, is located wherever x is at the time it changes from being F to being G. Some events are those of which another event is composed (e.g., the sinking of a ship seems composed of the sinkings of its parts). However, it also seems clear that not every group of events comprises another; there just is no event composed of a certain explosion on Venus and my birth. Any adequate theory about the nature of events must address the question of what properties, if any, such things have essentially. One issue is whether the causes (or effects) of events are essential to those events. A second is whether it is essential to each event that it be a change in the entity it is in fact a change in. A third is whether it is essential to each event that it occur at the time at which it in fact occurs. A chief component of a theory of events is a criterion of identity, a principle giving conditions necessary and sufficient for an event e and an event eH to be one and the same event. Quine holds that events may be identified with the temporal parts of physical objects, and that events and physical objects would thus share the same condition of identity: sameness of spatiotemporal location. Davidson once proposed that events are identical provided they have the same causes and effects. More recently, Davidson abandoned this position in favor of Quine’s. Kim takes an event to be the exemplification of a property (or relation) by an object (or objects) at a time. This idea has led to his view that an event e is the same as an event eH if and only if e and eH are the exemplifications of the same property by the same object(s) at the same time. Lombard’s view is a variation on this account, and is derived from the idea of events as the changes that physical objects undergo when they alter. See also CAUSATION, DAVIDSON, META- PHYSICS , PERDURANCE , QUIN. L.B.L.