blocktheory

Block theory, also known as the block universe theory or four-dimensionalism, is a metaphysical account of time. It holds that all points in time—past, present, and future—are equally real, and that the flow or passage of time is an illusion. In this view, the universe is a four-dimensional spacetime block in which events are fixed within spacetime and objects are extended through time as temporal parts rather than fully existing only in the present.

The theory is motivated by the structure of relativity. Minkowski’s formulation of spacetime and the relativistic view that simultaneity is relative challenge the idea of a unique, objective present. Proponents argue that a four-dimensional ontology more faithfully tracks the facts about events, causation, and change across time. Persistence is typically described as four-dimensional: objects are extended in time and possess temporal parts, a position associated with perdurantism, as opposed to endurantism, which treats objects as wholly present at each moment.

Block theory contrasts most directly with presentism, which holds that only the present exists, and with growing block theory, which posits that the past and present exist while the future does not. Supporters appeal to the explanatory power of relativity and to our best scientific worldview, while critics contend that it clashes with everyday experience of temporal passage, raises questions about free will and determinism, and relies on controversial ontological commitments. The debate remains a central topic in the philosophy of time, with discussions often focusing on ontology, modality, and the interpretation of spacetime.