Stephen Barker

This book develops a new metaphysical framework in which time is motion through a higher dimension. In other words, time literally flows. It breaks through the long debate about time flow and temporal experience in metaphysics by offering an entirely new approach that reconciles psychological time with the time of science. Our experience of change and our own being in time reveals a relentless motion or passage. Time really appears to flow. This apparent time motion is a profound enigma for currently well-known conceptions of time. This book develops a new theory of time that renders temporal passage fully intelligible. It treats time motion seriously by building in motion as a metaphysically fundamental feature of the physical universe, whose principal form is through higher-dimensional space. This motion-first metaphysics rejects the orthodox view that motion is explained in terms of space and time; rather, it uses space and motion to define time. Furthermore, it solves puzzles of time, change, and persistence, and is consistent with special relativity. The Metaphysically Dynamic Universe will appeal to researchers and graduate students interested in philosophy of time, metaphysics, and philosophy of physics.

The idea that temporal passage is literally time motion is proposed. The metaphysical framework that can make sense of this idea is motion-first metaphysics: motion is fundamental aspect of the world, irreducible to spatiotemporal facts, and higher dimensional. Three basic metaphysical frameworks are sketched: being-first, being-becoming dualism, and becoming-first. The first is essentially a change-reductionist view, rejecting passage and embracing eternalism. The second is the framework of contemporary ‘dynamic’ theories of time, and the third is the unexplored conception, that motion-first will occupy. The motion-first frame is sketched, whose features include the reinterpretation of the physicist’s 4D manifold M, time as motion through M’s 4th dimension, and dynamic geometry. Time perception involves perception of motion through M’s 4th dimension without a separate perception as-of the dimension being moved through.

This chapter provides a phenomenological sketch of temporal passage and temporal experience. It’s argued that using the standard concepts of time, persistence, and change, we cannot provide adequate phenomenological descriptions of our perceptions of change and persistence. Rather we need the concept of non-extensive flow. With that proposal in place, a characterisation of temporal passage is provided: (i) The present is a realm of non-extensive flow; the present time elapses; (ii) What’s now is absolute but changes; times are constantly gaining and losing presentness; (iii) Future times continually decrease in degree of futurity, and past times continually increase in degree of posterity; (iv) This process in (i)–(iii) is always happening. I introduce the core notion of overthrowing of now-totalities, and the requirement that there cannot be any metaphysically privileged duration of presence.

This chapter describes motion-first’s theory of tense, which has four notable aspects: (i) the present tense is the fundamental tense and presentness is simply occurrence, understood in irreducibly dynamic terms. ‘Present/now’ are non-indexical; (ii) the duration of what’s now/present is a conventional matter, but the present lacks space-like extension; (iii) Pastness and futurity are derived from the fundamental dynamicity of U’s transit through M. (iv) Motion-first transcends the debate about ontological status of past, present and future. We cannot assert ontological sameness or difference in relation to past, present, and future. A dynamic interpretation of special relativity is offered, which, although non-Minkowskian, entirely embraces the relativity of simultaneity, time dilation, and spatial contraction.

A new kind of solution to Zeno’s paradoxes compatible with the motion-first metaphysics of motion-first is described and defended. The core contention is that Zeno is pointing out a conflict between motion, as irreducible flow, and concepts of time, in particular, a commitment to time-points. The key to the paradoxes is the question of how motion can involve irreducible flow yet we still divide motion into stages, as in when we time motions. The standard solutions to Zeno’s paradoxes simply deny flow. That’s why they are being-first solutions. Motion-first’s solution keeps flow but reconciles it with time-division with its metaphysically dynamic concept of times.

The being-becoming dualist conception is outlined, comprising views like presentism, growing-block, and moving spotlight. These views are committed to temporal passage. It’s argued that: (i) Dualism cannot explain the phenomenology of experience of change, which requires non-extensive flow; (ii) Dualism is unconfirmable by experience—there is no way of confirming, for example, that only the present exists; (iii) Dualism is incoherent, since the two sides of the duality cannot be reconciled as aspects of one concrete reality. With respect to issue (iii), four approaches to dualist theory of becoming are considered: (a) a tense-logical reduction; (b) fragmentalism; (c) primitive becoming; (d) primitive mundane change. All these views encounter explanatory deficiencies and antinomies.

This chapter describes motion-first’s dynamic model of persisting things and concrete reality. In motion-first, persisting things are dynamic intersections. This is a new kind of theory of entities, accompanied by a new theory property-possession as irreducibly dynamic. Physical matter is defined by patterns of flow through M’s 4th dimension given the necessity of the flow. 3D motion and its relativity is discussed. Motion-first’s conception of objects surviving through change is examined, and shown to imply that the persistence of things over time transcends both identity and numerical difference. In persisting, an object at one time becomes the object at another, where object-becoming is irreducibly dynamic.

The motion-first metaphysics is introduced. The first idea is that motion is transit, a fundamental flow through a space. I outline five core aspects of transit: (i) non-locatedness and exclusion of time-points, (ii) non-extensiveness, (iii) with intrinsic direction, (iv) tensed character with now-duration conventionality, and (v) dynamic divisibility. If entities move by transit, they cannot persist by perduring, exduring, or enduring. Persistence must be higher-dimensional transit. This idea requires a reinterpretation of the physicist’s manifold M. To explain persisting entities a new dynamic geometry, utilizing the notion of a dynamic intersection is required. The thesis that time is higher-dimensional motion is restated. The necessity implicit in U’s underived transit through M is examined. The nature of U and M is described, and motion-first’s conception of the open future is briefly characterized.

This chapter describes motion-first’s model of temporal passage. The model implies literal time motion. It’s shown how it provides a coherent conception of the four aspects of passage: dynamic present, change of what’s absolutely now, the receding of the past and approaching of the future, and presentness of passage. Motion-first is immune to anti-passage arguments such as McTaggart’s puzzle, the argument from rate, and debunking arguments. I show how motion-first is immune to the antinomies that afflict dualist theories, like presentism. Motion-first can also solve the phenomenological puzzle of our perceptions of change and explain how we can have direct knowledge of the fact that we are in a world of passage.