In "Changing the Past" (2010), Peter van Inwagen argues that a time traveler can change the past without paradox in a growing block universe. After erasing the portion of past existence that generates paradox, a new, non-paradox-generating block can be "grown" after the temporal relocation of the time traveler. -/- I articulate and explore the underlying mechanism of Van Inwagen's model: the time traveler's control over the location of the objective present. Van Inwagen's model is aimed at preventing paradox by (...) changing the past, but it achieves something broader than paradox avoidance: it gives tools for a new model of time travel. I use van Inwagen's tools to develop a new kind of time travel in which in which the location of the objective present is shifted by the time traveler. I call this type of time travel Movable Objective Present, or MOP. After defining MOP, I argue that it is compatible with any theory of time that accepts hypertime, including presentism and moving spotlight theory. (shrink)

The plane was going to crash, but it didn't. Johnny was going to bleed to death, but he didn't. Geach sees here a changing future. In this paper, I develop Geach's primary argument for the (almost universally rejected) thesis that the future is mutable (an argument from the nature of prevention), respond to the most serious objections such a view faces, and consider how Geach's view bears on traditional debates concerning divine foreknowledge and human freedom. As I hope to show, (...) Geach's view constitutes a radically new view on the logic of future contingents, and deserves the status of a theoretical contender in these debates. (shrink)

Everyone agrees that we can’t change the past. But what about the future? Though the thought that we can change the future is familiar from popular discourse, it enjoys virtually no support from philosophers, contemporary or otherwise. In this paper, I argue that the thesis that the future is mutable has far more going for it than anyone has yet realized. The view, I hope to show, gains support from the nature of prevention, can provide a new way of responding (...) to arguments for fatalism, can account for the utility of total knowledge of the future, and can help in providing an account of the semantics of the English progressive. On the view developed, the future is mutable in the following sense: perhaps, once, it was true that you would never come to read a paper defending the mutability of the future. And then the future changed. And now you will. (shrink)

At least since Aristotle’s famous 'sea-battle' passages in On Interpretation 9, some substantial minority of philosophers has been attracted to the doctrine of the open future--the doctrine that future contingent statements are not true. But, prima facie, such views seem inconsistent with the following intuition: if something has happened, then (looking back) it was the case that it would happen. How can it be that, looking forwards, it isn’t true that there will be a sea battle, while also being true (...) that, looking backwards, it was the case that there would be a sea battle? This tension forms, in large part, what might be called the problem of future contingents. A dominant trend in temporal logic and semantic theorizing about future contingents seeks to validate both intuitions. Theorists in this tradition--including some interpretations of Aristotle, but paradigmatically, Thomason (1970), as well as more recent developments in Belnap, et. al (2001) and MacFarlane (2003, 2014)--have argued that the apparent tension between the intuitions is in fact merely apparent. In short, such theorists seek to maintain both of the following two theses: (i) the open future: Future contingents are not true, and (ii) retro-closure: From the fact that something is true, it follows that it was the case that it would be true. It is well-known that reflection on the problem of future contingents has in many ways been inspired by importantly parallel issues regarding divine foreknowledge and indeterminism. In this paper, we take up this perspective, and ask what accepting both the open future and retro-closure predicts about omniscience. When we theorize about a perfect knower, we are theorizing about what an ideal agent ought to believe. Our contention is that there isn’t an acceptable view of ideally rational belief given the assumptions of the open future and retro-closure, and thus this casts doubt on the conjunction of those assumptions. (shrink)

The moving spotlight account (MS) is a view that combines an eternalist ontology and an A-theoretic metaphysics. The intuition underlying MS is that the present time is somehow privileged and experientially vivid, as if it were illuminated by a moving spotlight. According to MS-theorists, a key reason to prefer MS to B-theoretic eternalism is that our experience of time supports it. We argue that this is false. To this end, we formulate a new family of positions in the philosophy of (...) time, which differ from MS in that, intuitively, they admit a plurality of moving spotlights. We argue that these ‘deviant’ variants of MS cannot be dismissed as conceptually incoherent, and that they are as well-supported by our experience as is MS. One of these variants, however, is consistent with the B-theory. Thus, if our experience of time supports MS, then it supports the B-theory as well. (shrink)

Open futurism is the indeterministic position according to which the future is ‘open’, i.e., there is now no fact of the matter as to what future contingent events will actually obtain. Many open futurists hold a branching conception of time, in which a variety of possible futures exist. This paper introduces two challenges to branching-time open futurism, which are similar in spirit to a challenge posed by Fine to tense realism. The paper argues that, to address the new challenges, open (...) futurists must adopt an objective, non-perspectival notion of actuality and subscribe to an A-theoretic, dynamic conception of reality. Moreover, given a natural understanding of “actual future”, it is perfectly sensible for open futurists to hold that a unique, objectively actual future exists, contrary to a common assumption in the current debate. The paper also contends that recognising the existence of a unique actual future helps open futurists to avoid potential misconceptions. (shrink)

The problem of freedom and determinism has vexed philosophers for several millennia, and continues to be a topic of lively debate today. One of the proposed solutions to the problem that has received a great deal of attention is the Theory of Agent Causation. While the theory has enjoyed its share of advocates, and perhaps more than its share of critics, the theory’s advocates and critics have always agreed on one thing: the Theory of Agent Causation is an incompatibilist theory. (...) That is, both believers and nonbelievers in the theory have taken it for granted that the most plausible version of the Theory of Agent Causation is one according to which freedom and determinism are incompatible. In fact, so entrenched is this assumption that no one on either side of the debate has ever questioned it. Yet it turns out that this assumption is wrong – the most plausible version of the Theory of Agent Causation is a compatibilist one. (shrink)

The Theory of Agent Causation has always been formulated as an incompatibilist view, but I think that this has been a mistake. The aim of this paper is to argue that, contrary to what agent causation theorists and their opponents have always believed, the most plausible version of the Theory of Agent Causation is actually a compatibilist version of that theory. I formulate the traditional version of the Theory of Agent Causation, and consider a series of objections to it and (...) related views. With each objection comes a corresponding revision of the theory that is motivated by that objection, and with each revision the theory becomes increasingly compatibilistic until, finally, we arrive at a completely compatibilistic version of the Theory of Agent Causation, which I take to be the most plausible version of that theory. (shrink)

If there is a second dimension of time – a so-called ‘hypertime’ – is it logically possible for the past to change? Some have said yes; others have said no. I say yes provided that one has the appropriate ontological view of hypertime. So far, the ontology of hypertime has seldom been discussed. As such, this paper not only defends the logical possibility of a changing past, but aims to start a discussion on what ontological commitments are required to make (...) sense of a changing past. (shrink)

According to the prevailing sentiment, changing the past is logically impossible. The prevailing sentiment is wrong. In this paper, I argue that the claim that changing the past entails a contradiction ultimately rests upon an empirical assumption, and so the conclusion that changing the past is logically impossible is to be resisted. I then present and discuss a model of time which drops the empirical assumption and coherently models changing the past. Finally, I defend the model, and changing the past, (...) against objections. (shrink)

Some philosophers argue that any attempt to model changing the past will either be contradictory or really model avoiding the past. Using Nicholas Smith's (1997) argument as a basis, I formulate a generic version of this Avoidance Argument. I argue that the Avoidance Argument fails because (i) it involves an equivocation of what is meant by ‘bifurcation of the time of an event’ and (ii) resolving the equivocation results in the falsity of at least one of the premises. Hence, the (...) Avoidance Argument will not support the claim that changing the past is logically impossible. (shrink)

Agent-causal accounts of free will face two problems. First, such a view needs an account of rational free action, that is, of acting for reasons when one acts freely. And second, an intelligible explication of causation by an agent is required. This paper addresses both of these problems. Free actions are seen as caused both by prior events and by agents. Reasons (or their mental representations) can then be seen as figuring causally when one freely acts for reasons. It is (...) suggested that agent causation can be given a non-reductive theoretical definition, as on some views event causation is. (shrink)

The standard philosophical view of time travel has it that time travelers cannot change the past. It has been argued by some that the standard view is false, and that this can be shown using a two-dimensional model of time. I defend the standard view against this attack. I show, first, that the addition of a second temporal dimension does not provide a model of changing the past and, second, that neither does the addition of n temporal dimensions for any (...) n > 1. (shrink)

In this paper I address issues related to the problem of future contingents and the metaphysical doctrine of fatalism. Two classical responses to the problem of future contingents are the third truth value view and the all-false view. According to the former, future contingents take a third truth value which goes beyond truth and falsity. According to the latter, they are all false. I here illustrate and discuss two ways to respectively argue for those two views. Both ways are similar (...) in spirit and intimately connected with fatalism, in the sense that they engage with the doctrine of fatalism and accept a large part of a standard fatalistic machinery. (shrink)

Ross P. Cameron argues that the flow of time is a genuine feature of reality. He suggests that the best version of the A-Theory is a version of the Moving Spotlight view, according to which past and future beings are real, but there is nonetheless an objectively privileged present. Cameron argues that the Moving Spotlight theory should be viewed as having more in common with Presentism than with the B-Theory. Furthermore, it provides the best account of truthmakers for claims about (...) what was or will be the case. Cameron goes on to defend an account of the open future, and argues that this is a better account than that available to the Growing Block theory. (shrink)

The question of whether humans are free to make their own decisions has long been debated and it continues to be a controversial topic today. In _Free Will: The Basics_ readers are provided with a clear and accessible introduction to this central but challenging philosophical problem. The questions which are discussed include: Does free will exist? Or is it illusory? Can we be free even if everything is determined by a chain of causes? If our actions are not determined, does (...) this mean they are just random or a matter of luck? In order to have the kind of freedom required for moral responsibility, must we have alternatives? What can recent developments in science tell us about the existence of free will? Because these questions are discussed without prejudicing one view over others and all technical terminology is clearly explained, this book is an ideal introduction to free will for the uninitiated._ _. (shrink)

Sets out the basic theory of normal modal and temporal propositional logics; applies this theory to logics of discrete (integer), dense (rational), and continuous (real) time, to the temporal logic of henceforth, next, and until, and to the propositional dynamic logic of regular programs.

In what follows, I will contend that the commonsense view of ourselves as fundamental causal agents - for which some have used the term “unmoved movers" but which I think might more accurately be expressed as “not wholly moved movers” - is theoretically understandable, internally consistent, and consistent with what we have thus far come to know about the nature and workings of the natural world. In the section that follows, I try to show how the concept of ‘agent’ causation (...) can be understood as a distinct species (from ‘event’ causation) of the primitive idea, which I’ll term “causal production”, underlying realist or non-Humean conceptions of event causation. In section III, I respond to a number of contemporary objections to the theory of agent causation. Sections IV-V are devoted to showing that the theory is compatible with ordinary reasons explanations of action, which then places me in a position to respond, in the final section, to the contention that we could never know, in principle, whether the agency theory actually describes a significant portion of human activity. (shrink)

I Introduction This essay will canvass recent philosophical accounts of human agency that deploy a notion of 'self' (or 'agent') causation. Some of these accounts try to explicate this notion, whereas others only hint at its nature by way of contrast with the causality exhibited by impersonal physical systems. In these latter theories, the authors' main argumentative burden is that the apparent fundamental differences between personal and impersonal causal activity strongly suggest mind-body dualism. I begin by noting two distinct, yet (...) not commonly distinguished, philosophical motivations for pursuing an agent-causal account of human agency. In the course of discussing the accounts that some philosophers have developed in response to these considerations, I reconsider both the linkage of agent causation with mind-body dualism and its sharp cleavage from impersonal (or 'event') causation. (shrink)