Daniel Deasy

Meyer (Erkenntnis 89:463–478, 2024) argues that the Moving Spotlight Theory (MST) of time entails the falsehood of the widely-accepted tense-logical principles that what is true always will have been true (∀p(p → GPp)) and that what is true always was going to be true (∀p(p → HFp)). In this article, I describe Meyer’s argument as I understand it (Sect. 2); argue that MST does not have this strange consequence (Sect. 3); and attempt to diagnose the source of Meyer’s error (Sect. 4). My aim is not simply to respond to Meyer’s argument on behalf of MST, but to gain a better understanding of the theory and of the source of a certain family of objections that are typically raised against it.

We examine moving spotlight theories of time: theories according to which there are past and future events and an objective present moment. In Section 1, we briefly discuss the origins of the view. In Section 2, we describe the traditional moving spotlight view, which we understand as an ‘enriched’ B-theory of time, and raise some problems for that view. In the next two sections, we describe versions of the moving spotlight view that we think are better and which solve those problems. In Section 3, we describe a version of the view that combines permanentism – the thesis that all things always exist – with propositional temporalism, the thesis that some propositions are sometimes true and sometimes false. In Section 4, we discuss a version of the view that is like an ‘enriched’ presentism. We conclude with some brief thoughts on issues that remain outstanding.

Realists about possible worlds typically identify possible worlds with abstract objects, such as propositions or properties. However, they face a significant objection due to Lewis (1986), to the effect that there is no way to explain how possible worlds-as-abstract objects represent possibilities. In this paper, I describe a response to this objection on behalf of realists. The response is to identify possible worlds with propositions, but to deny that propositions are abstract objects, or indeed objects at all. Instead, I argue that realists should follow Prior (1971) and others in treating higher-order quantification (e.g. quantification into predicate or sentence position) as a genuine form of quantification in its own right, and so in particular, not to be analysed in terms of first-order quantification over abstract objects. I argue that from this ‘higher-orderist’ perspective, there is a relatively straightforward answer to the question of how possible worlds-as-propositions succeed in representing possibilities.

This paper defends Priorianism, a theory in the philosophy of time which combines three theses: first, that there is a metaphysical distinction between the present time and non-present times; second, that there are temporary propositions, that is, propositions that change in truth-value simpliciter over time; and third, that there is change over time only if there are temporary propositions. Priorianism is accepted by many Presentists, Growing Block Theorists, and Moving Spotlight Theorists. However, it is difficult to defend the view without appealing to premises that those who reject the view find controversial. My aim in this paper is to defend Priorianism in a way that largely avoids appealing to such premises. I do three things: first (Section 1), I describe the component theses of Priorianism and the relations between them. Next (Section 2), I show how Priorians can respond to the argument that the B-theory implies that there are temporary propositions, and therefore satisfies the Priorian condition for there being change over time. Finally (Section 3), I defend the Priorian thesis that there is change over time only if there are temporary propositions against an alternative principle of change defended by Ross Cameron (The Moving Spotlight, 2015).

Some Presentists—according to whom everything is present—identify instants of time with propositions of a certain kind. However, the view that times are propositions seems to be at odds with Presentism: if there are times then there are past times, and therefore things that are past; but how could there be things that are past if everything is present? In this paper, we describe the Presentist view that times are propositions ; we set out the argument that Presentism is incompatible with the view that times are propositions ; and then we describe three possible responses to that argument on behalf of Presentists who identify times with propositions. We argue that each of these responses comes with significant costs. Finally, we describe a fourth possible response—according to which times are irreducibly higher-order entities—which appears to avoid the costs of the other three. We also describe and respond to two objections to the higher-order strategy.

Some theories in the philosophy of time combine a commitment to the existence of non-present regions of spacetime with the view that there is a perspective-independent present time. We call such theories 4D A-theories. There is a well-known objection to 4D A-theories, as follows: 4D A-theories entail that the vast majority of subjects across time believe falsely that they are present. But if the vast majority of subjects across time believe falsely that they are present, we do not know that we are present. We call this the Epistemic Objection to 4D A-theories. In this paper we do two things: first, we describe and assess a number of different versions of the Epistemic Objection. We argue that there is only one version of the objection—the version due to Russell that we call the Safety Argument—that does not rely on implausible epistemic principles which entail radical scepticism. Second, we raise objections to the main strategies adopted by 4D A-theorists in response to the Safety Argument. We conclude that the Epistemic Objection—in the form of the Safety Argument—remains a threat to 4D A-theories.

Recently, some authors – call them Reformists – have argued that the traditional Presentism-Eternalism and Actualism-Possibilism debates in the metaphysics of time and modality respectively are unclear or insubstantial, and should therefore give way to the newer Temporaryism-Permanentism and Contingentism- Necessitism debates. In ‘On characterising the presentism/eternalism and actualism/possibilism debates’ (2016, Analytic Philosophy 57: 110-140), Ross Cameron defends the Conservative position that the traditional debates are both substantial and distinct from the Temporaryism-Permanentism and Contingentism- Necessitism debates. In this paper I provide a Reformist response to Cameron’s arguments.

Bradford Skow’s Objective Becoming (2015) is a strikingly original and philosophically rich contribution to contemporary philosophy of time. The book rewards very careful study, and is surely a ‘must-read’ for anyone with an interest in current debates concerning time and change. Perhaps the most immediately compelling aspect of the book is its leading question: if I [Skow] didn’t already accept the ‘block universe theory’ (BU),1 which theory of time would I defend? Skow’s surprising (and, from my perspective, welcome!) answer is that he would defend some version of the Moving Spotlight Theory (MST). However, Skow’s reason for this answer is less familiar: it is that MST—unlike BU and its popular rival Presentism—‘contains robust passage’. Skow goes on to (quite convincingly, in my view) defend two versions of MST against a number of common objections: ‘MST-Supertense’ and ‘MST-Time’. In the first part of this paper (§1), I investigate the question of what it is for a theory to contain robust passage in Skow’s sense. In particular, I argue that given Skow’s arguments in favour of robust passage, he should probably not count MST-Time as a theory that contains robust passage. I also argue that there are better reasons to reject BU than those Skow describes. In the second part of the paper (§2), I focus on Skow’s MST-Supertense. I argue that there are reasons for MSTers to reject MST-Supertense in favour of a more ‘traditional’ version of MST (the view I call ‘Classic MST’).

Presentism is typically characterised as the thesis that everything is present, and therefore there are no dinosaurs or Martian presidential inaugurations. Putting aside the vexed question of exactly what it is to be present in this context, this thesis seems quite straightforward. However, a number of authors—such as Merricks, Lombard, Meyer, Tallant and Sakon —have argued that Presentism so characterised is either trivially true or false even by Presentist lights. This is the so-called Triviality Argument against Presentism. In this paper I show that three of the four premises of the Triviality Argument are plausibly false. I conclude that Presentists have nothing to fear from the Triviality Argument.

The aim of this paper is to describe and defend the moving spotlight theory of time. I characterise the moving spotlight theory as the conjunction of two theses: permanentism, the thesis that everything exists forever, and the A-theory, the thesis that there is an absolute, objective present time. I begin in Sect. 2 by clearing up some common misconceptions about the moving spotlight theory, focusing on the discussion of the theory in Sider. In doing so, I also fill-out the barebones picture of the moving spotlight theory as the conjunction of permanentism and the A-theory. In Sect. 3 I show how moving spotlighters can avoid the two common objections to their view, the McTaggartian argument that the view is contradictory, and the epistemic argument that the view implies that we should believe we are not located at the present moment. I conclude that the moving spotlight theory does not deserve its current relative unpopularity.

Different versions of the A-theory of time are traditionally defined in terms of whether everything is present, or whether there are also past and future things. In this paper I argue that the traditional way of defining A-theories should be abandoned. I focus on the traditional definition of presentism, according to which always, everything is present. First, I argue that there are good reasons to reject all the most plausible interpretations of the predicate ‘is present’ as it appears in the traditional definition of presentism. It follows that there are also good reasons to reject the most plausible interpretations of the traditional definitions of the other A-theories. I then argue that there is a better way of defining the A-theories, in terms of the question of whether existence has a beginning and an end. Finally, I argue that what goes for the traditional definition of presentism goes for the traditional definition of its modal analogue actualism, according to which necessarily, everything is actual : there are good reasons to reject the traditional definition of actualism in favour of a definition in terms of contingent existence.

According to the A-theory of time some instant of time is absolutely present. Many reject the A-theory on the grounds that it is inconsistent with current spacetime physics, which appears to leave no room for absolute presentness. However, some reject the A-theory on purely philosophical grounds. In this article I describe three purely philosophical arguments against the A-theory and show that there are plausible A-theoretic responses to each of them. I conclude that, whatever else is wrong with the A-theory, it is not obviously a philosophically suspect theory.