Temporal Properties and Temporal Change

Core Idea

Temporal properties are features objects possess only relative to times (being young, being red, being in motion). Understanding whether temporal properties are intrinsic, how they relate to persistence and change, and whether they require presentism or tensedness is central to metaphysical theories of time and dynamics.

Explainer

From philosophy-of-time, you know the debate between A-theorists (who hold that temporal passage — past, present, future — is metaphysically fundamental) and B-theorists (who hold that time is just an ordered series of events with no privileged "now"). From properties-intrinsic-extrinsic, you know that intrinsic properties are those a thing has in virtue of how it alone is, independent of its relations to other things. Temporal properties combine both concepts, and doing so generates one of the deepest puzzles in the metaphysics of change.

The puzzle is called the problem of temporary intrinsics, articulated clearly by David Lewis. You are seated now, and in an hour you will be standing. Being seated and being standing seem like intrinsic properties — they describe how you are, not your relations to other things. But a single object cannot simultaneously be both intrinsically seated and intrinsically standing; those seem genuinely contradictory. How does one persisting object bear contradictory intrinsic properties at different times? The problem is sharp because it involves three individually plausible commitments that jointly create a contradiction: (1) properties like being-seated are intrinsic, (2) objects persist through time and change these properties, (3) an object cannot have contradictory intrinsic properties.

Three responses structure the debate. The presentist (A-theorist) solution dissolves the problem by denying that past and future times are real: only the present exists, so only present properties are instantiated. "Being seated" is true of you now; the future standing is not yet real. There is no contradiction because only one state currently obtains. The perdurance (four-dimensionalist) solution rejects the idea that you are wholly present at each time: you are a temporally extended four-dimensional object, and what appear to be conflicting temporal properties are actually properties of distinct temporal parts. Your seated-stage has the intrinsic property of being-seated; your standing-stage has being-standing. No single entity bears both. The endurance solution holds that you are wholly present at each time, but temporal properties are not monadic intrinsics — they are *relations to times*. You stand-at-t₁ and sit-at-t₂, where these are irreducibly relational facts rather than intrinsic ones.

The stakes extend well beyond a technical puzzle. How you resolve the problem of temporary intrinsics commits you to a view about what kind of thing you are — a three-dimensional entity wholly present at each moment, or a four-dimensional worm extended through time as through space. This interacts with your view on the metaphysics of time itself: presentism is naturally allied with A-theory, four-dimensionalism fits smoothly with B-theory's eternalist picture of time, and endurance can be combined with either but requires care about what "relations to times" amount to in a tensed versus tenseless framework. These commitments carry forward into stage theory and the analysis of personal identity.