This paper presents a line of thought against the possibility of causation without time. That possibility, insofar as it is supposedly rested upon a Lewisian counterfactual theory of causation, does not stand up to scrutiny. The key point is that, as a reflection on the trans-world identity of events reveals, (distinct) events deprived of times are—according to Lewis’s own semantics of counterfactuals—no longer eligible to stand in counterfactual dependence.

'The arrow of time' refers to the curious asymmetry that distinguishes the future from the past. Reversing the Arrow of Time argues that there is an intimate link between the symmetries of 'time itself' and time reversal symmetry in physical theories, which has wide-ranging implications for both physics and its philosophy. This link helps to clarify how we can learn about the symmetries of our world, how to understand the relationship between symmetries and what is real, and how to overcome (...) pervasive illusions about the direction of time. Roberts explains the significance of time reversal in a way that intertwines physics and philosophy, to establish what the arrow of time means and how we can come to know it. This book is both mathematically and philosophically rigorous yet remains accessible to advanced undergraduates in physics and the philosophy of physics. This title is also available as Open Access on Cambridge Core. (shrink)

It is often said that the world is explained by laws of nature together with initial conditions. But does that mean initial conditions don’t require further explanation? And does the explanatory role played by initial conditions entail or require that time has a preferred direction? This chapter looks at the use of the ‘initialness defence’ in physics, the idea that initial conditions are intrinsically special in that they don’t require further explanation, unlike the state of the world at other times. (...) Such defences commonly assume a primitive directionality of time to distinguish between initial and final conditions. Using the case study of the time-asymmetry of thermodynamics and the so-called ‘past hypothesis’ — the hypothesis that the early universe was in a state of very low entropy —, I outline and support a deflationary account of the initialness defence that does not pre- suppose a basic directionality of time, and argue that there is a relevant explanatory asymmetry between initial conditions and the state of systems at other times only if certain causal conditions are satisfied. Hence, the initialness defence is available to those who reject a fundamental direction of time. (shrink)

Modern physics has provided a range of motivations for holding time to be fundamentally undirected. But how does a temporally adirectional metaphysics, or ‘C-theory’ of time, fit with the time of experience? In this chapter, I look at what kind of problem human time poses for C-theories. First, I ask whether there is a ‘hard problem’ of human time: whether it is in principle impossible to have the kinds of experience we do in a temporally adirectional world. Second I consider (...) the ‘easy problem’: how specific directed aspects of our temporal experience are to be explained by C-theorists. This leads to a greater issue: is there such a thing as an experience of time direction at all to even be explained? I show how the kinds of experience we have that we typically associate with the idea of time being directed can be accommodated within a directionless picture of time. (shrink)

The perplexing nature of time has been more contemplated, speculated, written, and debated about over the ages than virtually any other subject, with the possible exception of religion. Yet time seems more elusive than the vast majority of other metaphysical concepts. Time remains mysterious, for we lack an understanding of time at a basic physical level. Concepts of time in theories of modern physics and time as found in contemporary western analytic philosophy are discussed.

David Lewis (1979) has argued that according to his possible worlds analysis of counterfactuals, “backtracking” counterfactuals of the form “If event A were to happen at tA, then event B would happen at tB” where tB precedes tA, are usually false if B does not actually happen at tB. On the other..

Quantum mechanics portrays the universe as involving non-local influences that are difficult to reconcile with relativity theory. By postulating backward causation, retro-causal interpretations of quantum mechanics could circumvent these influences and accordingly reconcile quantum mechanics with relativity. The postulation of backward causation poses various challenges for the retro-causal interpretations of quantum mechanics and for the existing conceptual frameworks for analyzing counterfactual dependence, causation and causal explanation. In this chapter, we analyze the nature of time, causation and explanation in a local, (...) deterministic retro-causal interpretation of quantum mechanics that is inspired by Bohmian mechanics. This interpretation of quantum mechanics offers a deterministic, local ‘hidden-variables’ model of the Einstein-Podolsky-Rosen experiment that poses a new challenge for Reichenbach’s principle of the common cause. In this model, the common cause – the state of particles at the emission from the source – screens off the correlation between its effects – the distant measurement outcomes – but nevertheless fails to explain the correlation between the effects. (shrink)

© The Author 2017. Published by Oxford University Press on behalf of The Analysis Trust. All rights reserved. For Permissions, please email: [email protected] Boonin’s The Non-Identity Problem and the Ethics of Future People and Rivka Weinberg’s The Risk of a Lifetime: How, When and Why Procreation May Be Permissible are both important books for those interested in procreative ethics. Each argues for surprising and controversial conclusions: Boonin argues that we should solve the non-identity problem by accepting its apparently unacceptable conclusion (...) that actions cannot be wrong due to their effects on future people whose lives are worth living and who would not exist were the actions not performed; Weinberg argues that there is no non-identity problem, that future children have no interest in existing, but significant interest in avoiding harm and that procreation is, therefore, a much more morally risky business than we tend to think. Even if... (shrink)

Statistical mechanics involves probabilities. At the same time, most approaches to the foundations of statistical mechanics--programs whose goal is to understand the macroscopic laws of thermal physics from the point of view of microphysics--are classical; they begin with the assumption that the underlying dynamical laws that govern the microscopic furniture of the world are deterministic. This raises some potential puzzles about the proper interpretation of these probabilities.

Is the common cause principle merely one of a set of useful heuristics for discovering causal relations, or is it rather a piece of heavy duty metaphysics, capable of grounding the direction of causation itself? Since the principle was introduced in Reichenbach’s groundbreaking work The Direction of Time (1956), there have been a series of attempts to pursue the latter program—to take the probabilistic relationships constitutive of the principle of the common cause and use them to ground the direction of (...) causation. These attempts have not all explicitly appealed to the principle as originally formulated; it has also appeared in the guise of independence conditions, counterfactual overdetermination, and, in the causal modelling literature, as the causal markov condition. In this paper, I identify a set of difficulties for grounding the asymmetry of causation on the principle and its descendents. The first difficulty, concerning what I call the vertical placement of causation, consists of a tension between considerations that drive towards the macroscopic scale, and considerations that drive towards the microscopic scale—the worry is that these considerations cannot both be comfortably accommodated. The second difficulty consists of a novel potential counterexample to the principle based on the familiar Einstein Podolsky Rosen (EPR) correlations in quantum mechanics. (shrink)

The present article proposes to re-examine the parity-of-reasoning or double-standard fallacy argument, which favours a time-symmetric Gold universe model over a cosmological arrow of time. There are two reasons for this re-examination. One is empirical: the recent discovery of an expanding and accelerating universe questions the symmetry assumption of the Gold universe on empirical grounds. The other is theoretical: the argument from t-symmetry fails to take into account some important aspects of the topology of phase space and recently developed typicality (...) arguments. If the parity-of-reasoning argument, which depends on the t-symmetry of probability, is reconsidered in terms of the topology of phase space and typicality arguments, the double-standard fallacy argument loses much of its appeal. The Gold universe model itself suffers from unexplained dynamic asymmetries. The upshot of this article is that the Gold universe model is implausible or far less plausible than asymmetric models. (shrink)

Bell’s theorem is purported to demonstrate the impossibility of a local “hidden variable” theory underpinning quantum mechanics. It relies on the well-known assumption of ‘locality’, and also on a little-examined assumption called ‘statistical independence’ (SI). Violations of this assumption have variously been thought to suggest “backward causation”, a “conspiracy” on the part of nature, or the denial of “free will”. It will be shown here that these are spurious worries, and that denial of SI simply implies nonlocal correlation between spacelike (...) degrees of freedom. Lorentz-invariant theories in which SI does not hold are easily constructed: two are exhibited here. It is conjectured, on this basis, that quantum-mechanical phenomena may be modeled by a local theory after all. (shrink)

I argue that the Carroll-Chen cosmogonic model does not provide a plausible scientific explanation of the past hypothesis (the thesis that our universe began in an extremely low-entropy state). I suggest that this counts as a welcomed result for those who adopt a Mill-Ramsey-Lewis best systems account of laws and maintain that the past hypothesis is a brute fact that is a non-dynamical law.

Several philosophers have maintained in recent years that the endurance/perdurance debate is merely verbal: these prima facie distinct theories of objects’ persistence are in fact metaphysically equivalent, they claim. The present paper challenges this view. Three proposed translation schemes are examined; all are shown to be faulty. In the process, constructive reasons for regarding the debate as a substantive one are provided. It is also suggested that the theories may have differing practical implications.

An increasing number of experiments at the Belle, BNL, CERN, DAΦNE and SLAC accelerators are confirming the violation of time reversal invariance (T). The violation signifies a fundamental asymmetry between the past and future and calls for a major shift in the way we think about time. Here we show that processes which violate T symmetry induce destructive interference between different paths that the universe can take through time. The interference eliminates all paths except for two that represent continuously forwards (...) and continuously backwards time evolution. Evidence from the accelerator experiments indicates which path the universe is effectively following. This work may provide fresh insight into the long-standing problem of modeling the dynamics of T violation processes. It suggests that T violation has previously unknown, large-scale physical effects and that these effects underlie the origin of the unidirectionality of time. It may have implications for the Wheeler-DeWitt equation of canonical quantum gravity. Finally it provides a view of the quantum nature of time itself. (shrink)

T violation has previously been shown to induce destructive interference between different paths that the universe can take through time which leads to a new quantum equation of motion called bievolution. Here we examine further details of the interference and clarify the conditions needed for the bievolution equation.

All the attempts to find the justification of the privileged evolution of phenomena exclusively in the external world need to refer to the inescapable fact that we are living in such an asymmetric universe. This leads us to look for the origin of the “arrow of time” in the relationship between the subject and the world. The anthropic argument shows that the arrow of time is the condition of the possibility of emergence and maintenance of life in the universe. Moreover, (...) according to Bohr’s, Poincaré’s and Watanabe’s analysis, this agreement between the earlier-later direction of entropy increase and the past-future direction of life is the very condition of the possibility for meaningful action, representation and creation. Beyond this relationship of logical necessity between the meaning process and the arrow of time the question of their possible physical connection is explored. To answer affirmatively to this question, the meaning process is modelled as an evolving tree-like structure, called “Semantic Time”, where thermodynamic irreversibility can be shown. (shrink)

This paper suggests an epistemic interpretation of Belnap’s branching space-times theory based on Everett’s relative state formulation of the measurement operation in quantum mechanics. The informational branching models of the universe are evolving structures defined from a partial ordering relation on the set of memory states of the impersonal observer. The totally ordered set of their information contents defines a linear “time” scale to which the decoherent alternative histories of the informational universe can be referred—which is quite necessary for assigning (...) them a probability distribution. The “historical” state of a physical system is represented in an appropriate extended Hilbert space and an algebra of multi-branch operators is developed. An age operator computes the informational depth of historical states and its standard deviation can be used to provide a universal information/energy uncertainty relation. An information operator computes the encoding complexity of historical states, the rate of change of its average value accounting for the process of correlation destruction inherent to the branching dynamics. In the informational branching models of the universe, the asymmetry of phenomena in nature appears as a mere consequence of the subject’s activity of measuring, which defines the flow of time-information. (shrink)

The aim of this article is to analyse the relation between the second law of thermodynamics and the so-called arrow of time. For this purpose, a number of different aspects in this arrow of time are distinguished, in particular those of time-reversal (non-)invariance and of (ir)reversibility. Next I review versions of the second law in the work of Carnot, Clausius, Kelvin, Planck, Gibbs, Caratheodory and Lieb and Yngvason, and investigate their connection with these aspects of the arrow of time. It (...) is shown that this connection varies a great deal along with these formulations of the second law. According to the famous formulation by Planck, the second law expresses the irreversibility of natural processes. But in many other formulations irreversibility or even time-reversal non-invariance plays no role. I therefore argue for the view that the second law has nothing to do with the arrow of time. (shrink)

The purpose of this paper is two fold: first, I look to show Oaklander’s theory of time to be false. Second, I show that the only way to salvage the B-theory is via the adopting of the causal theory of time, and allying this to Oaklander’s claim that tense is to be eliminated. I then raise some concerns with the causal theory of time. My conclusion is that, if one adopts eternalism, the unreality of time looks a better option than (...) the B-theory. (shrink)

The New A-theory of Time is the view, to be elaborated and defended in this article, that many times exist, and that time is real in virtue of every moment in time bearing each of the so-called A-properties: past, present and future. I argue that TNAT is at least as theoretically virtuous as mainstream views in the philosophy of time and may have some claim to being our best theory of time. I show that the properties ‘past’, ‘present’ and ‘future’ (...) can be understood as compatible intrinsic properties. Having demonstrated that this account of the A-properties is coherent, I go on to demonstrate how TNAT can give us an account of passage, change and the truth-conditions for temporal sentences. In the final section of the article, I develop a tentative argument in favour of TNAT, though concede that we have to settle for the result that TNAT is on a par with our other theories of time. In the remainder of this opening section, my aim is to situate the current proposal as a direct response to Mc.. (shrink)

Within the philosophy of time there has been a growing interest in positions that deny the reality of time. Those positions, whether motivated by arguments from physics or metaphysics, have a shared conclusion: time is not real. What has not been made wholly clear, however, is exactly what it entails to deny the reality of time. Time is unreal, sure. But what does that mean? There has been only one sustained attempt to spell out exactly what it would mean to (...) endorse a temporal error theory; a theory that denies the reality of time—Baron & Miller’s ‘What is temporal error theory?’. Despite the fact that their paper makes significant strides in spelling out what would be required of a temporal error theory, my claim in this paper is that their position must be rejected and replaced. As well as looking to reject Baron and Miller’s position, I also look to provide that replacement. (shrink)

Timothy Williamson thinks that every object is a necessary, eternal existent. In defense of his view, Williamson appeals primarily to considerations from modal and tense logic. While I am uncertain about his modal claims, I think there are good metaphysical reasons to believe permanentism: the principle that everything always exists. B-theorists of time and change have long denied that objects change with respect to unqualified existence. But aside from Williamson, nearly all A-theorists defend temporaryism: the principle that there are temporary (...) existents. I think A-theorists are better off without this added commitment, but I will not argue for that in any great detail here. Instead, I will contend that a very tempting A-theoretic argument for temporaryism is unsound. In the first half of the paper, I will develop the Moorean “common sense” argument for temporaryism and dispute its central premise, namely that temporaryism is a valid generalization from highly plausible beliefs about change. I will argue that given the pervasive vagueness in our ordinary beliefs about change and the background commitments of all A-theories, no party can claim to be the common sense view because no party can accommodate most of our common sense beliefs about change in existence. In the second half of the paper, I will propose a permanentist A-theory that explains all change over time as a species of property change. I call it the minimal A-theory, since it dispenses with the change in existence assumption. As we'll see, the permanentist alternative performs well enough in explaining our ordinary beliefs about change, and it has better prospects for answering some objections commonly levied against A-theories. (shrink)

A‐theorists of time postulate a deep distinction between the present, past and future. Settling on an appropriate logic for such a view is no easy matter. This Philosophy Compass article describes one of the most vexing formal problems facing A‐theorists. It is commonly thought that A‐theories can only be formally expressed in a tense logic: a logic with operators like P and F . And it seems natural to think that we live in a world where objects come to exist (...) and cease to exist as time passes. Indeed, this is typically a key component of the most prominent kind of A‐theory, presentism. But the temporary existence assumption cannot be upheld in any tense logic with a standard quantification theory. I will explain the problem and outline the philosophical and logical considerations that generate it. I will then consider two possible solutions to the problem – one that targets our logic of quantification and one that targets our assumptions about change. I survey the costs of each solution. (shrink)

A-theorists think there is a fundamental difference between the present and other times. This concern shows up in what kinds of properties they take to be instantiated, what objects they think exist and how they formalize their views. Nearly every contemporary A-theorist assumes that her metaphysics requires a tense logic – a logic with operators like and. In this paper, I show that there is at least one viable A-theory that does not require a logic with tense operators. And I (...) will argue that three common indispensability arguments for tense operators are unsound. (shrink)

The Relational Blockworld (RBW) interpretation of non-relativistic quantum mechanics (NRQM) is introduced. Accordingly, the spacetime of NRQM is a relational, non-separable blockworld whereby spatial distance is only defined between interacting trans-temporal objects. RBW is shown to provide a novel statistical interpretation of the wavefunction that deflates the measurement problem, as well as a geometric account of quantum entanglement and non-separability that satisfies locality per special relativity and is free of interpretative mystery. We present RBW’s acausal and adynamical resolution of the (...) so-called “quantum liar paradox,” an experimental set-up alleged to be problematic for a spacetime conception of reality, and conclude by speculating on RBW’s implications for quantum gravity. (shrink)

The ancient problem of whether our asymmetrical attitudes towards time are justified remains a live one in contemporary philosophy. Drawing on themes in the work of McTaggart, Parfit, and Heidegger, I argue that this problem is also a key concern of Kierkegaard’s Either/Or. Part I of Either/Or presents the “aesthete” as living a temporally volatilized form of life, devoid of temporal location, sequence and direction. Like Parfit’s character “Timeless,” these aesthetes are indifferent to the direction of time and seemingly do (...) not experience McTaggart’s “A-Series” mode of temporality. The “ethical” conception of time that Judge William offers in Part II contains an attempt to normativize the direction of time, by re-orienting the aesthete towards an awareness of time ’s finitude. However, the form of life Judge William articulates gives time sequentiality but not necessarily the robust directionality necessary to justify our asymmetrical attitudes to time. Hence while Either/Or raises this problem it remains unanswered until The Concept of Anxiety. Only with the eschatological understanding of time developed in The Concept of Anxiety does Kierkegaard answer the question of why directional and asymmetrical conative and affective attitudes towards time are normative. (shrink)

After rejecting substance dualism, some naturalists embrace patternism. It states that persons are bodies and that bodies are material machines running abstract person programs. Following Aristotle, these person programs are souls. Patternists adopt four-dimensionalist theories of persistence: Bodies are 3D stages of 4D lives. Patternism permits at least six types of life after death. It permits quantum immortality, teleportation, salvation through advanced technology, promotion out of a simulated reality, computational monadology, and the revision theory of resurrection.

This paper addresses a worry about backwards time travel. The worry is that there is something mysteriously inexplicable about the combination of commonplace events that will inevitably conspire to prevent the time traveler from doing something impossible such as killing her younger self. The worry is first distinguished from other problems for backwards time travel concerning its alleged impossibility or improbability. It is then shown that the worry is misplaced: there is in fact no real problem here. Yet the worry (...) has been widely expressed—so a suggestion is also made as to why it is so easy to get into the position of thinking that there is a genuine problem here, when in fact there is not. Finally, in light of the resolution of the inexplicability worry, a new way of dealing with the other two problems for backwards time travel—concerning its alleged impossibility and improbability—is proposed. (shrink)

No one denies that time and space are different; and it is easy to catalog differences between them. I can point my finger toward the west, but I can’t point my finger toward the future. If I choose, I can now move to the left, but I cannot now choose to move toward the past. And (as D. C. Williams points out) for many of us, our attitudes toward time differ from our attitudes toward space. We want to maximize our (...) temporal extent and minimize our spatial extent: we want to live as long as possible but we want to be thin.1 But these differences are not very deep, and don’t get at the essence of the difference between time and space. That’s what I want to understand: I want to know what makes time different from space. I want to know which difference is the fundamental difference between them. (shrink)

In this paper I distinguish interpretations of the question ``How fast does time pass?’’ that are important for the debate over the reality of objective becoming from interpretations that are not. Then I discuss how one theory that incorporates objective becoming—the moving spotlight theory of time—answers this question. It turns out that there are several ways to formulate the moving spotlight theory of time. One formulation says that time passes but it makes no sense to ask how fast; another formulation (...) says that time passes at one second per supersecond; and a third says that time passes at one second per second. I defend the intelligibility of this final version of the theory. (shrink)

Some philosophers believe that the passage of time is a real phenomenon. And some of them find a reason to believe this when they attend to features of their conscious experience. In fact this “argument from experience” is supposed to be one of the main arguments for passage. What exactly does this argument look like? Is it any good?

In this paper I assess the adequacy of no-conspiracy conditions employed in the usual derivations of the Bell inequality in the context of EPR correlations. First, I look at the EPR correlations from a purely phenomenological point of view and claim that common cause explanations of these cannot be ruled out. I argue that an appropriate common cause explanation requires that no-conspiracy conditions are re-interpreted as mere common cause-measurement independence conditions. In the right circumstances then, violations of measurement independence need (...) not entail any kind of conspiracy (nor backwards in time causation). To the contrary, if measurement operations in the EPR context are taken to be causally relevant in a specific way to the experiment outcomes, their explicit causal role provides the grounds for a common cause explanation of the corresponding correlations. (shrink)

I propose that, in addition to the commonly recognized increase of entropy, two more time arrows influence living beings. The increase of damage reactions, which produce aging and genetic variation, and the decrease of the rate of entropy production involved in natural selection are neglected arrows of time. Although based on the statistical theory of the arrow of time, they are distinguishable from the general arrow of the increase of entropy. Physiology under healthy conditions only obeys the increase of entropy (...) arrow. But aging, death, and evolution are determined by the other time arrows as well. Paradoxes emerge from conflicts among the specific determinisms associated with each arrow. These conflicts, along with uncertainties intrinsic to the low-number statistics of the arrows of damage reactions and decrease of the rate of production of entropy, highlight the limits of determinism at different levels of biology and its dependence on time span and number of organisms. The recognition of the three time arrows opens new perspectives for the problem of compatibility of the flow of time in physics and psychology. (shrink)

This article argues that time‐asymmetric processes in spacetime are enantiomorphs. Subsequently, the Kantian puzzle concerning enantiomorphs in space is reviewed to introduce a number of positions concerning enantiomorphy, and to arrive at a dilemma: one must either reject that orientations of enantiomorphs are determinate, or furnish space or objects with orientation. The discussion on space is then used to derive two problems in the debate on the direction of time. First, it is shown that certain kinds of reductionism about the (...) direction of time are at variance with the claim that orientation of enantiomorphic objects is intrinsic. Second, it is argued that reductive explanations of time‐asymmetric processes presuppose that enantiomorphic processes do not have determinate orientation. (shrink)

The nature of experience has been held to be a major reason for accepting the A-theory of time. I argue, however, that experience does not favour the A-theory over the B-theory; and that even if the A-theory were true it would not be possible to perceive the passage of time. The main argument for this draws on the constraint that a satisfactory theory of perception must explain why phenomenal characters map uniquely onto perceived worldly features. Thus, if passage is perceived, (...) it must be explained what makes one phenomenal character rather than another a perception of passage; and it must also be explained why that phenomenal character is a perception of passage rather than of some other feature of the world. I argue that no such explanation can be given, and consequently that passage cannot be perceived. I conclude that the A-theory is rendered unintelligible, and should therefore be rejected. (shrink)

A distinction is made between imagination in the narrow sense and in the broad sense. Narrow imagination is characterised as the ability to "see" pictures in the mind's eye or to "hear" melodies in the head. Broad imagination is taken to be the faculty of creating, either in the strict sense of making something ex nihilo or in the looser sense of seeing patterns in some data. The article focuses on a particular sort of broad imagination, the kind that has (...) to do with creating, not a work of art, a scientific theory or a political vision but one's own life. We shape our lives through our actions, and these actions not only influence our future—a commonplace—but also determine our past, which is a new and more controversial perspective. (shrink)

It is commonly thought that the statistical mechanical reversibility objection implies that our putative records of the past are more likely to have arisen as spontaneous fluctuations from equilibrium states than through causal processes that correctly indicate past states of affairs. Hence, so the story goes, without some further assumption that solves the reversibility objection, such as the past hypothesis, all our beliefs about the past would almost surely be false. This claim is disputed and it is argued that at (...) least some of our records of the past can and should be thought to be veridical because the intentional contents of records are not included as part of their statistical mechanical description. The fact that the present state of the world around us coheres so well with the way we would expect it to be if our records were veridical provides good evidence for the claim that they are produced via a common causal structure. (shrink)

The debate between A-theory and B-theory in the philosophy of time is a persistent one. It is not always clear, however, what the terms of this debate are. A-theorists are often lumped with a miscellaneous collection of heterodox doctrines: the view that only the present exists, that time flows relentlessly, or that presentness is a property (Williams 1996); that time passes, tense is unanalysable, or that earlier than and later than are defined in terms of pastness, presentness, and futurity (Bigelow (...) 1991); or that events or facts (as opposed to language) are “tensed” (Mellor 1993). B-theorists then argue that the A-theory is incoherent, using variants on J.M.E. McTaggart’s argument for the unreality of time (McTaggart 1927, ch. 33). (shrink)

During the last decades the physico-chemical conception of self-organization of chemical systems has been created. The chemical systems in natural-historical processes do not have any creator: they rise up from irreversible processes by self-organization. The issue of self-organization in physics has led to a new interpretation of the laws of nature. As Ilya Prigogine has shown, they do not express certainties but possibilities and describe a world that must be understood in a historical way. In the new philosophical understanding of (...) nature priority is not ascribed to any single type or level of entity, but to historical processes, to processes of endless generation and change. (shrink)

I discuss the nature of the puzzle about the time‐asymmetry of radiation and argue that its most common formulation is flawed. As a result, many proposed solutions fail to solve the real problem. I discuss a recent proposal of Mathias Frisch as an example of the tendency to address the wrong problem. I go on to suggest that the asymmetry of radiation, like the asymmetry of thermodynamics, results from the initial state of the universe.

In a recent paper, Malament (2004) employs a time reversal transformation that differs from the standard one, without explicitly arguing for it. This is a new and important understanding of time reversal that deserves arguing for in its own right. I argue that it improves upon the standard one. Recent discussion has focused on whether velocities should undergo a time reversal operation. I address a prior question: What is the proper notion of time reversal? This is important, for it will (...) affect our conclusion as to whether our best theories are time-reversal symmetric, and hence whether our spacetime is temporally oriented. *Received February 2007; revised March 2008. †To contact the author, please write to: Department of Philosophy, Yale University, P.O. Box 208306, New Haven, CT 06520-8306; e-mail: [email protected]. (shrink)

Appeals to the ‘common sense’, or ‘naïve’, or ‘folk’ concept of time, and the purported phenomenology as of time passing, play a substantial role in philosophical theorising about time. When making these appeals, philosophers have been content to draw upon their own assumptions about how non-philosophers think about time. This paper reviews a series of recent experiments bringing these assumptions into question. The results suggest that the way non-philosophers think about time is far less metaphysically demanding than philosophers have assumed.

I follow Hájek (Synthese 137:273–323, 2003c) by taking objective probability to be a function of two propositional arguments—that is, I take conditional probability as primitive. Writing the objective probability of q given r as P(q, r), I argue that r may be chosen to provide less than a complete and exact description of the world’s history or of its state at any time. It follows that nontrivial objective probabilities are possible in deterministic worlds and about the past. A very simple (...) chance–credence relation is also then natural, namely that reasonable credence equals objective probability. In other words, we should set our actual credence in a proposition equal to the proposition’s objective probability conditional on available background information. One advantage of that approach is that the background information is not subject to an admissibility requirement, as it is in standard formulations of the Principal Principle. Another advantage is that the “undermining” usually thought to follow from Humean supervenience can be avoided. Taking objective probability to be a two-argument function is not merely a technical matter, but provides us with vital flexibility in addressing significant philosophical issues. (shrink)

In this essay I address the issue of whether Einstein's Special Theory of Relativity counts against a tensed or "A-series" understanding of time. Though this debate is an old one, it continues to be lively with many prominent authors recently arguing that a genuine A-series is compatible with a relativistic world view. My aim in what follows is to outline why Special Relativity is thought to count against a tensed understanding of time and then to address the philosophical attempts to (...) reconcile the two theories. I conclude that while modern physics on its own does not rule out the possibility of a real A-series, the combination of Einstein's theory and the philosophical arguments against tense is decisive. The upshot is that the tenseless or "B-series" view of time is the best one. (shrink)

Tenseless theories of time entail that the only temporal properties exemplified by events are earlier than, simultaneous with, and later than. Such an account seems to conflict with our common experience of time, which suggests that the present moment is ontologically unique and that time flows. Some have argued that only a tensed account of time, one in which past, present and future are objective properties, can do justice to our experience. Any theory that claims that the world is different (...) from how we experience it must nonetheless be consistent with the having of that experience. Accordingly, in this essay I defend the tenseless theory by arguing that it can indeed account for certain key features of our experience of time without recourse to tensed properties. (shrink)

The problem of the irreversibility’s origin in thermodynamic processes occupies a distinguished place among many and lasting attempts by researchers to derive irreversibility from molecular-mechanical principles. However, this problem is still open and no universally accepted solution may be given during any course. In this paper, I shall try to show that the examining of Maxwell’s demon thought experiment may provide insight into the difficulties that emerge, looking for this origin because: (i) it is connected with the notion of irreversibility, (...) and (ii) one of its functions is that of the “reversibility objection.” In order to illustrate this point, I study Boltzmann’s approach to the problem of a molecular-mechanical interpretation of irreversibility and I show that an auxiliary assumption (the selected direction of time) is responsible for producing irreversibility. But this result is accordant with the predictions of Maxwell’s demon thought experiment: the assumptions of this kind are not dictated by molecular-mechanical principles but are separate input in the model-systems used. (shrink)