⧖ Time × ◉ Matter

Time & Matter

Change, causation, and impermanence

Matter is the substrate that changes, and time is the dimension through which that change unfolds. Causation — the idea that prior material states produce later ones — is the hinge that binds them. Without time, matter would be static; without matter, time would have nothing to mark its passage.

Does matter require time to exist, or does matter's activity create time? Process philosophers argue that becoming is more fundamental than being — that matter is not a thing persisting through time, but a process that constitutes it. Materialists counter that time is simply the measure of physical change in a pre-existing substance.
  • Is matter fundamentally persistent or fundamentally in process?
  • Does causation require temporal succession, or can causes be simultaneous with effects?
  • What makes material objects "the same" object across different moments of time?
  • Is entropy — the irreversible degradation of matter — the only reason time has a direction?

Time and matter are co-constitutive: matter gives time something to measure, and time gives matter the dimension in which to change. Their relationship is at the heart of every physical law, from conservation of energy to the second law of thermodynamics.