Occurrents

Occurrents, in ontology and the philosophy of time, are entities that persist through time by having temporal parts. They are things that unfold or occur in time, such as events, processes, states, or activities. An occurrent is typically contrasted with a non-temporal object that remains wholly present at each moment it exists.

The traditional contrast is with endurants (also called continuants). Endurants are wholly present at any time they exist and do not require temporal parts to be described, whereas occurrents extend in time and can be analyzed into successive temporal stages. The view that objects are extended in time and can be decomposed into temporal parts is often called perdurantism or four-dimensionalism; the term occurrent is commonly used as a synonym or close counterpart.

Temporal parts are central to the notion of occurrents. An occurrent can be divided into time-slices, each representing the state of the process at a moment or interval. For example, a thunderstorm, a musical performance, a growing tree, or a running software program can be treated as a sequence of temporal parts. This allows for tracking change, development, and the causal order of events within the duration of the occurrent.

Philosophical interest in occurrents concerns persistence, identity over time, and the relation between change and continuity. Debates explore how boundaries between temporal parts are drawn, how causation operates within an occurrent, and how occurrents relate to other ontological categories. Occurrents are foundational in discussions of time, change, and the structure of reality.