Temporal Passage and the Experience of Time

Whatever one's view of tense or the existence of times, there is a datum every theory must confront: time seems to pass. The present feels like a moving boundary; events approach, arrive, and recede; the future becomes present and slips into the past. Is this passage a real, objective feature of the world — time genuinely flowing — or is it a pervasive feature of how temporal beings experience a reality that does not itself flow? This is the problem of temporal passage, and it splits into two connected questions: whether passage is coherent as an objective feature, and, if it is not, why time nonetheless seems to pass.

This page examines the arguments against objective passage and the B-theorist's deflationary account of temporal experience; it presupposes the A/B and presentism/eternalism debates.

What would passage be?

The A-theorist holds that passage is objective: reality has a moving present, and the sum of what is present (or of what has happened) is continually updated. The metaphor is of a spotlight moving along the timeline, or of the "now" advancing, or of events becoming and then fading. The challenge is to cash the metaphor into a coherent literal claim — and here two classic objections bite.

The rate-of-passage regress

If time flows, it flows at some rate — but a rate is a change of one quantity with respect to another. Spatial motion has a rate: metres per second. What is the rate of time's passage? The only available answer is one second per second — which is not a rate at all but the dimensionless number 1, as empty as saying a stationary object moves "one metre per metre."

Press for a genuine rate and a regress threatens. If the present moves through time at some rate, that rate must be measured against a second time dimension (seconds of ordinary time per second of "hyper-time"), whose own flow needs a third time, and so on without end. Either passage has no rate (and then in what sense is it a motion?) or it launches an infinite hierarchy of times. This is a central plank of the "myth of passage" critique associated with Donald C. Williams and J. J. C. Smart: the notion of objective flow, on inspection, either collapses into triviality or generates absurd extra time dimensions. The B-theorist concludes that "passage" is not a coherent additional feature of reality at all — there are just events tenselessly ordered by earlier/later, and "flow" adds nothing intelligible.

The A-theorist's replies: deny that passage needs a rate (it is a primitive, sui generis feature, not a motion measured against anything); or accept "one second per second" as a perfectly good, if trivial-looking, truth that nonetheless reflects a real dynamic difference; or locate passage in the successive change of A-properties rather than in any "speed." Whether these rescue an objective passage or quietly reduce it to B-facts is exactly what is in dispute.

The B-theory's burden: explaining the appearance

If passage is not objective, the B-theorist owes an account of why it so insistently seems real — the sense of flow is not a subtle theoretical posit but a vivid feature of ordinary experience. The deflationary strategy explains the appearance from tenseless materials:

The dynamics of memory and knowledge. At each moment a conscious subject has memories of earlier moments but none of later ones; the store of memory grows monotonically along the thermodynamic/entropic gradient. Successive time-slices of a person each contain "more" recorded past. This asymmetric accumulation — itself grounded in the arrow of time — is what we mistake for the world's moving rather than our accumulating. There is no moving now; there is a sequence of person-stages each of which represents itself as present and remembers its predecessors.
The indexical "now." On the B-theory "now" is indexical, like "here." Each experience-token is, trivially, present to itself — it represents its own moment as "now" — so every momentary experience is accompanied by a sense of presentness. Strung together, these give the illusion of a single "now" that travels, when in fact there are many "nows," one per moment, each self-referentially present. (Compare: every place is "here" to someone there, but no place is objectively here.)

On this account passage is a robust and universal illusion with a tidy explanation — which the B-theorist counts as a virtue (the appearance is predicted) and the A-theorist counts as a bullet (an illusion this deep and universal is more plausibly a perception of something real).

The phenomenology of temporal experience

Independently of the metaphysics, the structure of temporal experience raises its own problems, studied since Augustine, James, and Husserl:

The specious present. We do not experience time as a knife-edge instant; we hear a melody, not an unextended tone, and perceive motion directly rather than inferring it. Experience seems to span a short temporal thickness — William James's "specious present" — within which succession is given. But how can a present experience present succession, which requires earlier and later?
Models of temporal awareness. Philosophers distinguish (i) the cinematic model — experience is a succession of static snapshots (which struggles to explain how motion is perceived rather than inferred); (ii) the retentional model (Husserl) — each momentary experience contains a "retention" of the just-past and a "protention" of the about-to-come, so succession is represented within a durationless now; and (iii) the extensional model — the experience itself is temporally extended and mirrors the succession it presents. Which model is right bears on whether the feeling of flow is evidence for objective passage or an artifact of how experience is structured.

The A-theorist argues that the immediacy of experienced succession and flow is best explained by real succession and flow. The B-theorist argues that the specious present and the retention/protention structure are perfectly reproducible in a tenseless world — indeed that a snapshot theory of experience plus memory dynamics predicts exactly the phenomenology we have, with no objective passage required.

Where this sits

Passage is the phenomenon that gives the temporal question its urgency: it is the strongest intuitive support for the A-theory and for presentism, and its apparent incoherence (the rate regress) and its deflationary explanation are the B-theory's strongest cards for the block universe. The account of why time seems to pass leans essentially on the arrow of time and its thermodynamic basis — memory grows because entropy grows. The next page takes up that arrow directly: whatever we say about passage, time has a direction, and its source is a deep and separate problem.