Why Time Puzzles Us — How Distinguishing 'Existence' from 'Occurrence' Clears the Fog

Time feels immediate and familiar, yet explaining what it is has tangled thinkers for millennia. Much of that confusion dissolves once we stop treating moments that happen as if they were material things that exist.

Ancient puzzles that still matter

St. Augustine captured the difficulty over 1,600 years ago when he wrote: “What then is time? If no one asks me, I know; if I want to explain it to a questioner, I do not know.” Centuries earlier, Heraclitus used the image of a river to show that things persist while changing: you cannot step into the same water twice because new water is always flowing by.

Parmenides argued that “what is, is; and what is not, is not,” and from that went on to treat past and future as equally part of reality. His student Zeno then produced paradoxes — like the halving argument for motion — intended to support this timeless view.

Where the thinking goes wrong

The central mistake in many classical and modern treatments is to conflate two distinct ideas: existence (things that persist in three dimensions) and occurrence (events that happen at particular times and places). When thinkers treat events — moments of happening — as if they were things that exist in the same sense as rocks, people or planets, arguments become circular or smuggle in hidden assumptions.

Zeno’s paradox, for example, disappears when you restore time to the analysis: distances may be subdivided indefinitely, but the time intervals used to traverse them shrink accordingly. The contradiction only appears if you fix spatial divisions while erasing the temporal ones.

Relativity, worldlines and the map-versus-territory error

Modern physics uses a four-dimensional model called space-time to represent occurrences: each point denotes an event and the continuous sequence of events tied to an object traces its worldline. That model is an extremely useful map for describing what happens, but the model itself should not be mistaken for an existent landscape.

Thinking of a worldline or space-time as an object you can “move through” commits the map-versus-territory error. This move is at the heart of many time-travel puzzles: if you imagine space-time as something that exists in the same way as a table or a person, it becomes tempting to imagine traversing it like a landscape. But events occur during the existence of things; they do not persist as independent, inhabitable things.

Cosmology’s clarifying perspective

From a cosmological point of view, the universe is a three-dimensional realm populated by existing objects — particles, stars, planets — that persist through time. The specific location of a particle at an instant is an event. Taken together, those events can be represented geometrically in space-time, but that geometric representation is a model of happenings, not an additional layer of being.

Why the distinction matters

Separate the categories of existence and occurrence, and Augustine's complaint becomes less mysterious: we know what time is in experience because we experience a world of enduring things in which events occur. The difficulty has been mostly linguistic and conceptual — treating occurrences as if they were the same kind of thing as persistent objects.

Keeping the distinction clear dissolves many supposed paradoxes (from Zeno to Parmenides to popular time-travel tropes) and shows why space-time is best read as a powerful descriptive map, not a traversable territory. Events happen; things exist. Once we respect that difference, the fog surrounding the nature of time lifts.