The Justified Ontology of Time

What are we justified in asserting when constructing an ontology of time? I believe a version of Presentism to be the only justified theory. ‘Justified’ here refers exclusively to a basis of empirical and epistemological evidence. What can we assert about the metaphysics of time when we start from a justificationist epistemology? Putnam and Rietdijk argue that the relativity of simultaneity supports Eternalism. My investigation examines the strength of justification Eternalism attains from the special theory of relativity (STR) and will argue that Eternalism is not justified by STR. I will also suggest that an alternative metaphysical theory of time, Point Presentism, attains justification from STR

String Theory, Loop Quantum Gravity and Eternalism

Eternalism, the view that what we regard locally as being located in the past, the present and the future equally exists, is the best ontological account of temporal existence in line with special and general relativity. However, special and general relativity are not fundamental theories and several research programs aim at finding a more fundamental theory of quantum gravity weaving together all we know from relativistic physics and quantum physics. Interestingly, some of these approaches assert that time is not fundamental. If time is not fundamental, what does it entail for eternalism and the standard debate over existence in time? First, I will argue that the non-fundamentality of time to be found in string theory entails standard eternalism. Second, I will argue that the non-fundamentality of time to be found in loop quantum gravity entails atemporal eternalism, namely a novel position in the spirit of standard eternalism

Presentism and Eternalism in Perspective

The distinction between presentism and eternalism is usually sought in some formula like ‘Only presently existing things exist’ or ‘Past, present, and future events are equally real’. I argue that ambiguities in the copula prevent these slogans from distinguishing significant opposed positions. I suggest in addition that one can find a series of significant distinctions if one takes spacetime structure into account. These presentisms and eternalisms are not contradictory. They are complementary elements of a complete naturalistic philosophy of time

Episodic memory, the cotemporality problem, and common sense

Direct realists about episodic memory claim that a rememberer has direct contact with a past event. But how is it possible to be acquainted with an event that ceased to exist? That’s the so-called cotemporality problem. The standard solution, proposed by Sven Bernecker, is to distinguish between the occurrence of an event and the existence of an event: an event ceases to occur without ceasing to exist. That’s the eternalist solution for the cotemporality problem. Nevertheless, some philosophers of memory claim that the adoption of an eternalist metaphysics of time would be too high a metaphysical price to be paid to hold direct realist intuitions about memory. Although I agree with these critics, I will try to show two things. First, that this kind of “common sense argument” is far from decisive. Second, that Bernecker’s proposal remains the best solution to the cotemporality problem

Defining Original Presentism

It is surprisingly hard to define presentism. Traditional definitions of the view, in terms of tensed existence statements, have turned out not to to be capable of convincingly distinguishing presentism from eternalism. Picking up on a recent proposal by Tallant, I suggest that we need to locate the break between eternalism and presentism on a much more fundamental level. The problem is that presentists have tried to express their view within a framework that is inherently eternalist. I call that framework the Fregean nexus, as it is defined by Frege’s atemporal understanding of predication. In particular, I show that the tense-logical understanding of tense which is treated as common ground in the debate rests on this very same Fregean nexus, and is thus inadequate for a proper definition of presentism. I contrast the Fregean nexus with what I call the original temporal nexus, which is based on an alternative, inherently temporal form of predication. Finally, I propose to define presentism in terms of the original temporal nexus, yielding original presentism. According to original presentism, temporal propositions are distinguished from atemporal ones not by aspects of their content, as they are on views based on the Fregean nexus, but by their form—in particular, by their form of predication

Relativity as Support for Presentism: A Modest Evidential Argument

Presentism is roughly the view that only the present exists. This view requires an absolute simultaneity relation. The special theory of relativity, however, is highly successful and does not account for absolute simultaneity. This is widely regarded as an evidential threat to presentism. In what follows, I propose a modest evidential argument in support of presentism on the basis of the physical evidence itself. A weak relativity postulate is shown to follow from a weak light-speed postulate. The weak light-speed postulate, in turn, is shown to be more probable on presentism than on its main rival doctrine, eternalism. Specifically, when one accounts for possible worlds in which the space-time metric is Euclidean (+,+,+,+) rather than Lorentzian (-,+,+,+), the empirical evidence turns out to be more probable on presentism than on eternalism. If successful, this argument provides modest evidential support for presentism and against eternalism. However, the support is drawn from an unexpected source: the physical evidence itself

Four-Dimensionalism, Evil, and Christian Belief

Four-dimensionalism and eternalism are theories on time, change, and persistence. Christian philosophers and theologians have adopted four-dimensional eternalism for various reasons. In this paper I shall attempt to argue that four-dimensional eternalism conflicts with Christian thought. Section I will lay out two varieties of four-dimensionalism—perdurantism and stage theory—along with the typically associated ontologies of time of eternalism and growing block. I shall contrast this with presentism and endurantism. Section II will look at some of the purported theological benefits of adopting four-dimensionalism and eternalism. Section III will examine arguments against four-dimensional eternalism from the problem of evil. Section IV will argue that four-dimensional eternalism causes problems for Christian eschatology

Liberated Presentism

(The version now posted is a revision of what was posted earlier. Final version now published.) The article gives a novel argument to show that there is sense of 'exists' suitable for posing a substantive issue between presentists and eternalists. It then seeks to invigorate a neglected variety of presentism. There are seven doctrines, widely accepted even among presentists, that create problems for presentism. Without distinguishing existence and being, presentists can comfortably reject all seven. Doing so would dispose of the majority of presentism’s problems. Further, it would enable presentists to reduce A-judgments to B-judgments, thereby insulating presentism from doubts about the intelligibility of A-theories. For reasons indicated very briefly, it might also make presentism less difficult to reconcile with special relativity, though the point is not pursued here

Time of Philosophers, Time of Physicists, Time of Mathematicians

Is presentism compatible with relativity ? This question has been much debated since the argument first proposed by Rietdijk and Putnam. The goal of this text is to study the implications of relativity and quantum mechanics on presentism, possibilism, and eternalism. We put the emphasis on the implicit metaphysical preconceptions underlying each of these different approaches to the question of time. We show that there exists a unique version of presentism which is both non-trivial, in the sense that it does not reduce the present to a unique event, and compatible with special relativity and quantum mechanics: the one in which the present of an observer at a point is identified with the backward light cone of that point. However, this compatibility is achieved at the cost of a renouncement to the notion of an objective, observer-independent reality. We also argue that no non-trivial version of presentism survives in general relativity, except if some mechanism forbids the existence of closed timelike curves, in which case precisely one version of possibilism does survive. We remark that the above physical theories force the presentist/possibilist's view of reality to shrink and break up, whereas the eternalist, on the contrary, is forced to grant the status of reality to more and more entities. Finally, we identify mathematics as the "deus ex machina" allowing the eternalist to unify his vision of reality into a coherent whole, and offer to him an "idealist deal": to accept a mathematical ontology in exchange for the assurance of surviving any physical theory.Comment: 24 pages, 10 figure