Perdurantists

Perdurantism is a metaphysical theory about persistence and identity over time. It holds that objects are four‑dimensional and consist of temporal parts, or "stage" or "temporal slice" parts, rather than enduring a single three‑dimensional entity throughout their existence. According to this view, an object at one moment is a distinct temporal part of a longer spatiotemporal entity, and identity over time is a relation among these parts.

The theory is often contrasted with endurantism, which maintains that objects are wholly present at every moment of their existence and persist by being wholly identical at successive times. Perdurantists argue that the temporal parts account for change, locomotion, and other temporal phenomena more naturally than the endurantist account. They also claim that perdurantism aligns better with how physics treats spacetime, treating objects as world‑tubes rather than as potentially discontinuous agents.

Key proponents include J. L. Mackie, who first introduced the temporal parts view, and David Lewis, who developed a robust version in his book "On the Plurality of Worlds". Other notable defenders include Paul Weiss, Nelson Goodman, and J. L. Mackie’s student, David Lewis’s colleague, and contemporary philosophers such as Andreas Schmidt and Robert D. Merrick. Critics, such as David J. Friedman, argue that perdurantism introduces unnecessary ontological complexity or fails to capture the intuitive of continuous identity. The debate touches on topics in metaphysics, the philosophy of time, and even neuroscience, as researchers examine how the mind represents temporal persistence.

While perdurantism remains a minority view, it has had significant influence on discussions of identity, persistence, and the structure of time. Its insistence that objects are spatiotemporally extended and composed of temporal parts continues to generate philosophical investigations into the nature of change and the foundations of ontology.