The cohabitation theory is a popular solution to the problem of personal fission. It affirms that all the people who result from fission were there cohabiting the pre-fission body all along. Adopting this solution is an uncontroversial move for four-dimensionalists, but is it open to three-dimensionalists too? Some have thought so, but Katherine Hawley, Mark Johnston, and Eric Olson have argued to the contrary. They claim three-dimensionalists simply cannot be cohabitation theorists. In this paper, I explain how they can.

. A typical textbook explanation of a rocket’s motion when its engine is fired appeals to momentum conservation: the rocket accelerates forward because its exhaust accelerates rearward and the system’s momentum must be conserved. This paper examines how this explanation works, considering three challenges it faces. First, the explanation does not proceed by describing the forces causing the rocket’s motion. Second, the rocket’s motion has a causal-mechanical explanation involving those forces. Third, if momentum conservation and the rearward motion of the (...) rocket’s exhaust explain why the rocket accelerates forward, then presumably momentum conservation and the rocket’s forward motion likewise explain why the rocket emits exhaust rearward. Explanatory circularity threatens to follow from this pair of explanations. This paper examines how the conservation-law explanation works and how it is compatible with the causal-mechanical explanation. The paper argues that these two explanations do not explain precisely the same fact relative to the same contrast class. The paper interprets the two conservation-law explanations as non-causal and argues that they yield no explanatory circularity. (shrink)

Thinking about time travel is an entertaining way to explore how to understand time and its location in the broad conceptual landscape that includes causation, fate, action, possibility, experience, and reality. It is uncontroversial that time travel towards the future exists, and time travel to the past is generally recognized as permitted by Einstein’s general theory of relativity, though no one knows yet whether nature truly allows it. Coherent time travel stories have added flair to traditional debates over the metaphysical (...) status of the past, the reality of temporal passage, and the existence of free will. Moreover, plausible models of time travel and time machines can be used to investigate the subtle relation between space-time structure and causality. -/- It surveys some philosophical issues concerning time travel and should serves as a quick introduction. It includes a new and improved way to define a time machine. (shrink)

John Searle has argued that all perceptual experiences are token-reflexive, in the sense that they are constituents of their own veridicality conditions. Many philosophers have found the kind of token-reflexivity he attributes to experiences, which I will call _causal_ token-reflexivity, unfaithful to perceptual phenomenology. In this paper, I develop an argument for a different sort of token-reflexivity in perceptual (as well as some non- perceptual) experiences, which I will call _temporal_ token-reflexivity, and which ought to be phenomenologically unobjectionable.

Many philosophers embrace grounding, supposedly a central notion of metaphysics. Grounding is widely assumed to be irreflexive, but recently a number of authors have questioned this assumption: according to them, it is at least possible that some facts ground themselves. The primary purpose of this paper is to problematize the notion of self-grounding through the theoretical roles usually assigned to grounding. The literature typically characterizes grounding as at least playing two central theoretical roles: a structuring role and an explanatory role. (...) Once we carefully spell out what playing these roles includes, however, we find that any notion of grounding that isn’t irreflexive fails to play these roles when they are interpreted narrowly, and is redundant for playing them when they are interpreted more broadly. The upshot is that no useful notion of grounding can allow a fact to ground itself. (shrink)

According to Humeanism about the laws, the laws of nature are nothing over and above certain kinds of regularities about particular facts. Humeanism has often been accused of circularity: according to scientific practice laws often explain their instances, but on the Humean view they also reduce to the mosaic, which includes those instances. In this paper I formulate the circularity problem in a way that avoids a number of controversial assumptions routinely taken for granted in the literature, and against which (...) many extant responses are therefore ineffective. I then propose a solution that denies the alleged Humean commitment that laws are explained by their instances. The solution satisfies three desiderata that other solutions don’t: it provides independent motivation against the idea that Humean laws are explained by their instances; it specifies the sense in which Humean laws are nonetheless “nothing over and above” their instances; and it gives an alternative account of what does explain the laws, if not their instances. This solution, I will argue, is not only the simplest but also the oldest one: it appeals only to tools and theses whose first appearance predates the earliest statements of the circularity problem itself. (shrink)

Many philosophers and non-philosophers who reflect on the causal antecedents of human action get the impression that no agent can have morally relevant freedom. Call this the ‘non-existence impression.’ The paper aims to understand the (often implicit) reasoning underlying this impression. On the most popular reconstructions, the reasoning relies on the assumption that either an action is the outcome of a chance process, or it is determined by factors that are beyond the agent’s control or which she did not bring (...) about. I argue that arguments based on this premise fail to apply to some possible agents for whom the non-existence impression arises. On the alternative reconstruction I offer, the impression rests on the assumption that free will requires being involved in the ultimate explanation of one’s actions in a novel sense in which nothing can be involved in the ultimate explanation of anything. (shrink)

A proper understanding of agentive modals promises to clarify issues to do with free will, know how, and other philosophically interesting topics. In this paper I identify one constraint on, and one structural feature of, trying-based versions of the conditional analysis of the agentive modals. I suggest that the constraint and structural feature together provide a novel account of why the famous Lehrer-Chisholm objection to conditional analyses of ability modals is so powerful. I argue that Mandelkern et al.’s ‘Agentive Modals’ (...) (Philosophical Review,126/3, 301–343, 2017) conditional analysis of the agentive modals fails to avoid this problem. I also identify two further problems for their account. I close by summarising a number of criteria which any successful semantic analysis of the agentive modals should satisfy. (shrink)

Christopher Franklin argues that, despite appearances, everyone thinks that the ability to do otherwise is required for free will and moral responsibility. Moreover, he says that the way to decide which ability to do otherwise is required will involve settling the nature of moral responsibility. In this paper I highlight one point on which those usually called leeway theorists - i.e. those who accept the need for alternatives - agree, in contradistinction to those who deny that the ability to do (...) otherwise is needed for free will. And I explain why it falsifies both of Franklin’s claims. (shrink)

In this paper, I examine how nudges affect the autonomy and freedom of those nudged. I consider two arguments put forth by Thaler and Sunstein for the claim that these effects can only be minor. According to the first of these arguments, nudges cannot significantly restrict a person’s autonomy or freedom since they are easy to resist. According to the second argument, the existence of nudges is inevitable, and thus, pursuing libertarian paternalism by nudging people doesn’t make a relevant difference (...) to people’s autonomy and freedom. After arguing that both of these arguments fail, I elucidate the general conditions in which, and the degrees to which, a person’s autonomy and freedom are affected by nudges. One focus of this discussion concerns how people’s autonomy and freedom are affected if—for example, due to progress in information technology—nudges become more effective, more individualized and more common, and affect more people. (shrink)

In her (1996) Kadri Vihvelin argues that autoinfanticide is nomologically impossible and so that there is no sense in which time travelers are able to commit it. In response, Theodore Sider (2002) defends the original Lewisian verdict (Lewis 1976) whereby, on a common understanding of ability, time travelers are able to kill their earlier selves and their failure to do so is merely coincidental. This paper constitutes a critical note on arguments put forward by both Sider and Vihvelin. I argue (...) that although Sider’s criticism starts out promisingly he doesn’t succeed in establishing that Vihvelin’s analysis fails, because (a) he neglects to rule out a class of counterfactuals to which Vihvelin’s sample-case may belong; and (b) (together with Lewis) he is wrong to suggest that future facts are irrelevant in the evaluation of time travelers’ abilities. I show instead that Vihvelin’s argument is viciously circular, indicating that even if there are nomological constraints on autoinfanticide these cannot be established a priori. (shrink)

Murray MacBeath, in his essay ``Time's Square'', describes a fictitious scenariowhere various physical observations made by the participants would, he claims, invitethe interpretation that time for them is two-dimensional. In the present paper, however, Iargue that such observations come close to underdetermining the hypothesis of time's twodimensionality;for a rival hypothesis - that, under certain circumstances, the observationscan be explained in terms of the familiar time dilation effects predicted by special relativity- almost fits the evidence as well. That is, under certain (...) (albeit artificial) circumstances theworld can already behave almost as though it were temporally two-dimensional. (shrink)

Currently popular theories of epistemic responsibility rest on the assumption that justification and excuse exhaust the relevant normative categories. One gets the sense that, once we've laid down the conditions for justified belief, and once we've laid down the conditions of excusably unjustified belief, the work is done; all that's left is to clock out. Against this backdrop, one is naturally led to think that if an agent's doxastic state fails to be justified, it is thereby unjustified, perhaps excusably so. (...) The aim of this paper is to argue that that natural thought is mistaken; some agents are epistemically incompetent, and in virtue of their incompetence, their doxastic states are neither justified nor unjustified. Instead, the doxastic states of such agents are exempt from epistemic evaluation altogether. I argue that what underlies this point about exemptions is that epistemic competences or abilities play an important and typically overlooked role in epistemology, especially in theories of epistemic responsibility. Here, I am interested in uncovering that role and explaining what it is, and also in explaining how one could accommodate it within various epistemological frameworks. (shrink)

A person is biased toward the future when she prefers, other things being equal, bad events to be in her past rather than her future or good ones to be in her future rather than her past. In this paper, I explain why both critics and defenders of future bias have failed to consider the best version of the view. I distinguish external time from personal time, and show that future bias is best construed in terms of the latter. This (...) understanding of future bias avoids several standard objections. I then consider a new justification of future bias which is consistent with that construal. My discussion points to a new position regarding the basic relation that grounds rational egoistic concern over time, according to which that relation is asymmetric between person-stages. I also explain how this way of justifying future bias would resolve the apparent tension between the future bias we display in our own case and our relative indifference toward the timing of the good and bad things that happen to other people. (shrink)

Punishing someone for a crime before they have committed it is widely considered morally abhorrent. But there is little agreement on what exactly is supposed to be wrong with it. In this paper, I critically evaluate several objections to the permissibility of prepunishment, making points along the way about the connections between time, knowledge, desert, deterrence and duty. I conclude that, although the conditions under which it could permissibly be administered are unlikely ever to arise in practice, nevertheless in principle, (...) nothing is wrong with prepunishment after all. (shrink)

ABSTRACT Frankfurt cases are often presented as counterexamples to the principle that one is morally responsible for one’s action only if one could have acted otherwise. But ‘could have acted otherwise’ is context-sensitive; it’s therefore open to a proponent of this principle to reply that although there is a salient sense in which agents in Frankfurt-style cases couldn’t have acted otherwise, there’s another, different sense in which they could have, and it is this latter sense which is relevant to what (...) we are morally responsible for doing. In this paper, I will evaluate the prospects of this contextualist response. I will argue that despite some initial signs of promise, the response fails, for reasons that were clearly anticipated in Frankfurt’s original paper. (shrink)

Time travel, it has been argued, leads to paradoxes, and in particular to a problem known as the grandfather paradox. Lewis has famously argued for the now standard view that the grandfather paradox is merely apparent. But underlying Lewis's solution is a faulty account of ability statements – one, according to which ability statements express possibility statements. I argue, contrary to Vihvelin and others, that an ameliorated view of ability statements allows for the same treatment of the seeming paradox. Hence, (...) Lewis's take on the grandfather paradox stands despite the failure of the particular view of ability statements it is built upon. (shrink)

According to the New Dispositionalist’s response to the Frankfurt Cases, Jones can do otherwise because Black merely masks (or finks), but does not deprive Jones of the relevant ability. This reasoning stands in the tradition of a line of thought according to which an informed view of the truth conditions of ability attributions allows for a compatibilist stance. The promise is that once we understand how abilities work, it turns out that the ability to do otherwise is compatible with determinism, (...) or with Black standing ready to intervene, or indeed both, as the New Dispositionalists hold. In this paper, I argue that this is mistaken. Understanding how abilities work gives us no reason to think that the ability to do otherwise relevant for free will is compatible with either Black’s presence or determinism. (shrink)

_ Belief: A Pragmatic Picture _ By ZimmermanAaron Z.Oxford University Press, 2018. viii + 180 pp.

There is a tradition, tracing back to Kant, of recasting metaphysical questions as questions about the utility of a conceptual scheme, linguistic framework, or methodological rule for achieving some particular end. Following in this tradition, I propose a ‘means-ends metaphysics ’, in which one rigorously demonstrates the suitability of some conceptual framework for achieving a specified goal. I illustrate this approach using a debate about the nature of events. Specifically, the question is whether the time at which an event occurs (...) is an essential property of that event. I argue that this question is naturally transformed into a question about the methodology of causal modeling. In this new framework, the question concerns what kind of variables to use to represent the effects of potential interventions on a system. This question has a demonstrably correct answer, which sheds new light on the original question. (shrink)

Lucy O'Brien has argued that defenders of the object-dependence of singular thought should attend to mental agency. A recent trend in action theory, towards what John Maier calls ‘agentive modality’, suggests that we conceive agency in terms of the exercise of abilities, and this is how I propose to approach O'Brien's challenge. For Gareth Evans, an early defender of object-dependence, maintained that thinking is the exercise of a complex of abilities. The debate about object-dependence gives way to the question whether (...) we have what I call dedicated singular mental abilities. In arguing that we do, I defend the thesis of object-dependence. (shrink)

Michael Tooley’s latest argument against the possibility of divine foreknowledge trades on the idea that, whichever theory of time is true, the ontology of the future—or lack thereof—gives rise to special problems for God’s prescience. I argue that Tooley’s reasoning is predicated on two mischaracterizations and conclude that, on at least some theories of time, the possibility of divine foreknowledge appears secure.

The advent of Frankfurt-style counterexamples in the early 1970s posed a problem not merely for incompatibilists, but for compatibilists also. At that time compatibilists too were concerned to hold that the presence of alternative possibilities was necessary for moral responsibility. Such a classical compatibilism, I argue in this paper, should not have been left behind. I propose that we can use a Kratzer-style semantics of ‘can’ to model ‘could have done otherwise’ statements in such a way that the truth of (...) such expressions is both (i) evidently consistent with determinism, and (ii) clearly such that Frankfurt-style counterexamples do not count as cases where the agent could not have done otherwise. (shrink)

There have been many objections to the possibility oftime travel. But all the truly interesting ones concern the possibility of reversecausation. What is objectionable about reverse causation? I diagnose that the trulyinteresting objections are to a further possibility: that of causal loops. I raisedoubts about whether there must be causal loops if reverse causation obtains; but devote themajority of the paper to describing, and dispelling concerns about, various kinds ofcausal loop. In short, I argue that they are neither logically nor (...) physically impossible.The only possibly objectionable feature that all causal loops share is that coincidenceis required to explain them. Just how coincidental a loop will be varies: some arereally quite ordinary, and some are incredibly unlikely. I end by speculating thatthe tendency amongst physicists to avoid discussion of causal loops involving intentionalaction may have been unfortunate, since intentional action is an excellent way tonon-mysteriously bring about what otherwise would have been an unlikely coincidence. Hencecausal loops may be more likely in a world with beings like us, than in one without. (shrink)

In the present paper, I offer a new argument to show that presentism about time is incompatible with time travel. Time travel requires leaving the present, which, under presentism, contains all of reality. Therefore to leave the present moment is to leave reality entirely; i.e. to go out of existence. Presentist “time travel” is therefore best seen as a form of suicide, not as a mode of transportation. Eternalists about time do not face the same difficulty, and time travel is (...) compossible with eternalism. (shrink)

In this paper I defend the compossibility of presentism and time travel from two objections. One objection is that the presentist’s model of time leaves nowhere to travel to; the second objection attempts to equate presentist time travel with suicide. After targeting some misplaced scrutiny of the first objection, I show that presentists have the resources to account for the facts that make for time travel on the traditional Lewisian view. In light of this ability, I argue that both of (...) the objections fail. (shrink)

One of the central problems of personal identity is to determine what we are essentially . In response to this problem, Lynne Rudder Baker espouses a psychological criterion, that is, she claims that persons are essentially psychological. Baker’s theory purports to bypass the problems of other psychological theories such as Dissociative Identity Disorder and the problem of individuating persons synchronically. I argue that the theory’s treatment of Dissociative Identity Disorder leads to untenable results, is invalid, and consequently fails to individuate (...) persons. (shrink)

A world in which time travel into the past occurred would seem like a most strange world. Nicholas Smith, however, in his ‘Bananas Enough for Time Travel’, argues that time travel is not so strange as we think. In particular, he argues against what he views as the main reason time travel worlds seem so strange – the claim that time travel entails unusual numbers of coincidences. I shall argue that Smith's argument for rejecting the claim is inadequate. Hence, the (...) debate over the consequences of the coincidences of time travel cannot be avoided by denying the coincidences themselves. (shrink)

A world in which time travel into the past occurred would seem like a most strange world. Nicholas Smith, however, in his ‘Bananas Enough for Time Travel’, argues that time travel is not so strange as we think. In particular, he argues against what he views as the main reason time travel worlds seem so strange – the claim that time travel entails unusual numbers of coincidences. I shall argue that Smith's argument for rejecting the claim is inadequate. Hence, the (...) debate over the consequences of the coincidences of time travel cannot be avoided by denying the coincidences themselves. (shrink)

Personal time, as opposed to external time, has a certain role to play in the correct account of death and immortality. But saying exactly what that role is, and what role remains for external time, is not straightforward. I formulate and defend accounts of death and immortality that specify these roles precisely.

There is a tension between Dispositionalism––the view that all metaphysical modality is grounded in actual irreducible dispositional properties––and the possibility of time travel. This is due to the fact that Dispositionalism makes it much harder to solve a potentiality-based version of the grandfather paradox. We first present a potentiality-based version of the grandfather paradox, stating that the following theses are inconsistent: 1) time travel is possible, 2) powers fully ground modality, 3) self-defeating actions are impossible, 4) time-travellers retain their intrinsic (...) powers upon time-travelling, and 5) time-travellers are ordinary agents with basic intrinsic potentialities. We then consider a number of potential solutions, and find them wanting. We argue that the metaphysical impossibility of performing a self-defeating action acts as a necessary perfect mask––while time-travel lets us “slip” the potentiality under the mask, thus generating the contradiction. We conclude considering what are the options for the dispositionalist. (shrink)

We propose an analysis of backward causation in terms of interventionism that can avoid several problems typically associated with backward causation. Its main advantage over other accounts is that it allows for reducing the problematic task of supporting backward causal claims to the unproblematic task of finding evidence for several ordinary forward directed causal hypotheses.

Ordinary disposition ascriptions appear to form a semantically heterogeneous class of clauses some of which can be straightforwardly analyzed as possibility claims, and some of which resist a simple quantificational treatment. For example, while “The block is breakable” is true if the block breaks at a relevant possible world, for “The block is fragile” to be true it doesn’t suffice that the block breaks at one of the worlds that matter to the evaluation of the ascription, since the block could (...) break accidentally and yet be sturdy. The contrast has been taken to indicate that sentences like “The block is fragile” don’t introduce mere existential quantification over sets of worlds, and should be represented as claims about sufficient ratios or proportions of worlds. However, recent work has suggested that by pairing the recalcitrant DAs with modified manifestation phrases, we can generalize the standard analysis of existential DAs to the problematic examples, and state a uniform characterization of DAs as claims of possibility. The paper discusses some counterexamples to the view that allegedly non-existential DAs are covert claims of fine-grained possibility, and sketches a hybrid account combining proportional quantification with fine-grained manifestations. (shrink)

In his well-known time travel story, David Lewis claims that there is a sense in which Tim can go back in time and kill his Grandfather and a (more inclusive) sense in which he cannot. Lewis describes Tim’s predicament as semi-fatalist, but holds that this does not compromise Tim’s freedom or his ability to kill Grandfather. I argue that if semi-fatalism is true of Tim, it is true of everyone, and that this is a troubling conclusion.

The quality of a life is typically understood as a function of the actual goods and bads in it, that is, its actual value. Likewise, the value of a population is typically taken to be a function of the actual value of the lives in it. We introduce an alternative understanding of life quality: adjusted value. A life’s adjusted value is a function of its actual value and its ideal value (the best value it could have had). The concept of (...) adjusted value is useful for at least three reasons. First, it fits our judgments about how well lives are going. Second, it allows us to avoid what we call False Equivalence, an error related to the non-identity problem. Third, when we use adjusted value as an input for calculating the value of a population, we can avoid two puzzles that Derek Parfit calls the “Repugnant Conclusion” and the “Mere Addition Paradox.”. (shrink)

In this dialogue I discuss the connection between eternalism and fatalism. I do not think, as some do, that eternalism implies fatalism, but I do think that eternalists can avoid fatalism only by denying a seemingly intuitive claim about what a traveller to the past cannot do.Export citation.

In this discussion piece, I argue that David Lewis fails to support his claim that time-travelling Tim cannot kill his Grandfather in 1921. This result, in turn, undermines Lewis’s contextualist solution to the Grandfather Paradox—i.e. conceding that Tim can and cannot kill Grandfather, but relative to different contexts in each case.

In this note, I argue that knowledge of an action’s effect undermines an agent’s reason to act. This undermining occurs in some cases of bringing about the past, but also in some cases of forwards causation. I consider the suggestion that it is not knowledge but truth that undermines reasons to act, giving rise to the spectre of fatalism. Thankfully, this spectre can be banished.

In this discussion I argue that, given the possibility of travel to the past, eternalists face a dilemma. They must choose between fatalism and the denial of an intuitive claim about what a traveller to the past cannot do. The eternalist should deny this seemingly intuitive claim which is in fact a version of fatalism about the past.

The starting point of the following considerations is a case study concerning the discovery of Halley's comet and the theoretical description of its path. It is shown that the set of objects involved in that system and the time interval during which their paths are observed are determined in a theory dependent way – thereby making use of the very theory later used for that system's theoretical description. Metatheoretical consequences this fact has with respect to the structuralist view of empirical (...) theories are discussed in detail. German Den Ausgangspunkt der folgenden Überlegungen bildet eine Fallstudie, die der Entdeckung und theoretischen Beschreibung des Halleyschen Kometen gewidmet ist. Es wird gezeigt, dass bei diesem System die Menge der involvierten Objekte und die Zeitintervalle, über die sich die Beobachtung der Bahnen dieser Objekte erstreckt, in theorieabhängiger Weise bestimmt werden – und zwar in Abhängigkeit von genau derjenigen Theorie, die anschließend zur theoretischen Beschreibung des Systems eingesetzt wird. Metatheoretische Konsequenzen, die sich aus diesem Umstand insbesondere für das strukturalistische Theorienkonzept ergeben, werden im Detail analysiert. (shrink)

The paper proposes a solution to the problem of counterfactuals, building on both Rescher’s epistemic and Tichý’s semantic approaches. The core of the proposed solution is the thesis that when expressing a true counterfactual, the speaker assumes a set of background indicative premises as an implicit parameter. When added tacitly to an unreal antecedent, these premises entail the consequent logically or analytically. We draw a distinction between a potentially unreal and an absolutely unreal condition expressed in the antecedent. We view (...) counterfactuals with a positive time vector and an absolute unreal condition as abbreviated deductive retrodictions. Similarly, we consider counterfactuals with a potentially unreal condition to be abbreviated deductive predictions. In a similar manner, we also explain the truth (falsity) of vacuously true counterpossibles or counterpossible conditionals. In the second part, we discuss the enigmatic backtracking counterfactuals. We propose that their negative time direction is due to their being abductive retrodictions, i.e., explanations of unreal effects based on possible causes in which the conditions remain tacit or unexpressed. The backtracking temporal direction of counterfactual abductive retrodictions is in accordance with the thesis on the positive temporal direction from cause to effect. Thus, we demonstrate that in order to explain backtracking counterfactuals, there is no need to assume violations of laws of nature or a special logic. What we need to do is to take into account the third parameter, i.e., a set of tacit or unexpressed additional propositions, as well as the principle of ceteris paribus as the background. (shrink)

Seemingly one of the most prominent issues that divide theorists about free will and moral responsibility concerns whether the ability to do otherwise is necessary for freedom and responsibility. I defend two claims in this paper. First, that this appearance is illusory: everyone thinks an ability to do otherwise is necessary for freedom and responsibility. The central issue is not whether the ability to do otherwise is necessary for freedom and responsibility but which abilities to do otherwise are necessary. Second, (...) I argue that we cannot determine which abilities are necessary until we have determined the nature and justification of moral responsibility. Thus, theorizing about moral responsibility ought to take pride of place in theorizing about free will. (shrink)

David Lewis objected to theories that posit necessary connections between distinct entities and to theories that involve a magical grasping of their primitives. In On the Plurality of Worlds, Lewis objected to nondescript ersatzism on these grounds. The literature contains several reconstructions of Lewis’ critique of nondescript ersatzism but none of these interpretations adequately address his main argument because they fail to see that Lewis’ critique is based on broader methodological considerations. I argue that a closer look at his methodology (...) reveals the broader objection he presented against nondescript ersatzism. This objection, I further argue, remains a challenge for the ersatzer who posits structure-less entities as possible worlds. (shrink)

We standardly evaluate counterfactuals and abilities in temporally asymmetric terms—by keeping the past fixed and holding the future open. Only future events depend counterfactually on what happens now. Past events do not. Conversely, past events are relevant to what abilities one has now in a way that future events are not. Lewis, Sider and others continue to evaluate counterfactuals and abilities in temporally asymmetric terms, even in cases of backwards time travel. I’ll argue that we need more temporally neutral methods. (...) The past shouldn’t always be held fixed, because backwards time travel requires backwards counterfactual dependence. Future events should sometimes be held fixed, because they’re in the causal history of the past, and agents have evidence of them independently of their decisions now. We need temporally neutral methods to maintain connections between causation, counterfactuals and evidence, and if counterfactuals are used to explain the temporal asymmetry of causation. (shrink)

The purpose of this essay is to clarify the notion of mnemonic content. Memories have content. However, it is not clear whether memories are about past events in the world, past states of our own minds, or some combination of those two elements. I suggest that any proposal about mnemonic content should help us understand why events are presented to us in memory as being in the past. I discuss three proposals about mnemonic content and, eventually, I put forward a (...) positive view. According to this view, when a subject seems to remember a certain event, that event is presented to her as making true a perceptual experience that caused the very memory experience that she is having. (shrink)

Do time travellers retain their normal freedom and abilities when they travel back in time? Lewis, Horwich and Sider argue that they do. Time-travelling Tim can kill his young grandfather, his younger self, or whomever else he pleases—and so, it seems can reasonably deliberate about whether to do these things. He might not succeed. But he is still just as free as a non-time traveller. I’ll disagree. The freedom of time travellers is limited by a rational constraint. Tim can’t reasonably (...) deliberate on killing his grandfather, certain that he’ll fail. If Tim follows his evidence, and appropriately self-predicts, he will be certain he won’t kill his grandfather. So if Tim is both evidentially and deliberatively rational, he can’t deliberate on killing his grandfather. This result has consequences. Firstly, it shows how evidential limits in the actual world contribute to our conception of the future as open. Secondly, it undercuts arguments against the possibility of time travel. Thirdly, it affects how we evaluate counterfactuals in time travel worlds, as well as our own. I’ll use the constraint to motivate an evidential and temporally neutral method of evaluating counterfactuals that holds fixed what a relevant deliberating agent has evidence of, independently of her decision. Using this method, an agent’s local abilities may be affected by what happens globally at other times, including the future. (shrink)

A plausible thought is that we should evaluate counterfactuals in the actual world by holding the present ‘fixed’; the state of the counterfactual world at the time of the antecedent, outside the area of the antecedent, is required to match that of the actual world. When used to evaluate counterfactuals in the actual world, this requirement may produce reasonable results. However, the requirement is deeply problematic when used in the context of explaining causal asymmetry. The requirement plays a crucial role (...) in certain statistical mechanical explanations of the temporal asymmetry of causation. I will use a case of backwards time travel to show how the requirement enforces certain features of counterfactual structure a priori. For this reason, the requirement cannot be part of a completely general method of evaluating counterfactuals. More importantly, the way the requirement enforces features of counterfactual structure prevents counterfactual structure being derived from more fundamental physical structure—as explanations of causal asymmetry demand. Therefore, the requirement cannot be used when explaining causal asymmetry. To explain causal asymmetry, we need more temporally neutral methods for evaluating counterfactuals—those that produce the right results in cases involving backwards time travel, as well as in the actual world. (shrink)