If an asymmetry in time does not arise from the fundamental dynamical laws of physics, it may be found in special boundary conditions. The argument normally goes that since thermodynamic entropy in the past is lower than in the future according to the Second Law of Thermodynamics, then tracing this back to the time around the Big Bang means the universe must have started off in a state of very low thermodynamic entropy: the Thermodynamic Past Hypothesis. In this paper, we (...) consider another boundary condition that plays a similar role, but for the decoherent arrow of time, i.e. the quantum state of the universe is more mixed in the future than in the past. According to what we call the Entanglement Past Hypothesis, the initial quantum state of the universe had very low entanglement entropy. We clarify the content of the Entanglement Past Hypothesis, compare it with the Thermodynamic Past Hypothesis, and identify some challenges and open questions for future research. (shrink)

The papers in this volume reflect much of the current unease of a world that perceives itself once more at the edge of chaos. The authors present different vistas of that experience and their inherent dialectic, expressed in numerous and ceaseless conflicts between ordering and disordering processes. They can be read as comments on the ongoing processes that lead toward greater complexity.

Henri Bergson (1859-1941) was once the most famous philosopher in the world, but his reputation waned in the latter half of the 20th century. Barry Allen here makes the case for Bergson as a great philosopher, one whose thought has much to contribute to contemporary philosophical questions. Living in Time presents chapters on each of Bergson's four major works, explaining his theories of time, perception, memory, and panpsychic consciousness, his innovative concept of virtual existence, his objection to Darwin, his controversy (...) with Einstein, his philosophy of creative evolution, and his social philosophy of closed and open society. In particular Allen focusses on Bergson's powerful ideas on time. Classical arguments for determinism fallaciously apply spatial concepts to consciousness; once we take time seriously, which means acknowledging its reality as duration and its difference from space, Bergson showed that the arguments for determinism become insupportable. Bergson's ideas on time and evolution offer a comparison with Nietzsche, which Allen develops, exposing both philosophical concurrence and systematic difference. The book's conclusion discusses the question of Bergson and naturalism and summarizes the ontology of the virtual that emerges as a core part of Bergson's thought. (shrink)

Many philosophers and scientists have claimed that time has an arrow that points in a special direction. The Roman poet Ovid may have referred to this one-way property of time when he said, “Time itself glides on with constant motion, ever as a flowing river.” However, understanding this arrow is not … Continue reading The Arrow of Time →.

It is often assumed that believing that p for a normative reason consists in nothing more than (i) believing that p for a reason and (ii) that reason’s corresponding to a normative reason to believe that p, where (i) and (ii) are independent factors. This is the Composite View. In this paper, we argue against the Composite View on extensional and theoretical grounds. We advocate an alternative that we call the Prime View. On this view, believing for a normative reason (...) is a distinctive achievement that isn’t exhausted by the mere conjunction of (i) and (ii). Its being an achievement entails that (i) and (ii) are not independent when one believes for a normative reason: minimally, (i) must hold because (ii) holds. Apart from its intrinsic interest, our discussion has important upshots for central issues in epistemology, including the analysis of doxastic justification, the epistemology of perception, and the place of competence in epistemology. (shrink)

This is a revised and expanded edition of a seminal work in the logic and philosophy of time, originally published in 1968. Arthur N. Prior was the founding father of temporal logic, and his book offers an excellent introduction to the fundamental questions in the field. Several important papers have been added to the original selection, as well as a comprehensive bibliography of Prior's work and an illuminating interview with his widow, Mary Prior. In addition, the Polish logic which made (...) Prior's writings difficult for many readers has been replaced by standard logical notation. This new edition will secure the classic status of the book. (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)

This open access monograph offers a detailed study and a systematic defense of a key intuition we typically have, as human beings, with respect to the nature of time: the intuition that the future is open, whereas the past is fixed. For example, whereas it seems unsettled whether there will be a fourth world war, it is settled that there was a first world war. -/- The book contributes, in particular, three major and original insights. First, it provides a coherent, (...) non-metaphorical, and metaphysically illuminating elucidation of the intuition. Second, it determines which model of the temporal structure of the world is most appropriate to accommodate the intuition, and settles on a specific version of the Growing Block Theory of time (GBT). Third, it puts forward a naturalistic foundation for GBT, by exploiting recent results of our best physics (viz. General Relativity, Quantum Mechanics, and Quantum Gravity). Three main challenges are addressed: the dismissal of temporal asymmetries as non-fundamental phenomena only (e.g., thermodynamic or causal phenomena), the epistemic objection against GBT, and the apparent tension between GBT and relativistic physics. It is argued that the asymmetry between the open future and the fixed past must be grounded in the temporal structure of the world, and that this is neither precluded by our epistemic device, nor by the latest approaches to Quantum Gravity (​e.g., the Causal Set Theory). -/- Aiming at reconciling time as we find it in ordinary experience and time as physics describes it, this ​innovative book ​will raise the interest of both academic researchers and ​graduate students working on the philosophy of time. More generally, it ​presents contents of interest for all metaphysicians and non-dogmatic philosophers of physics. (shrink)

This book is a treatise on time and on background independence in physics. It first considers how time is conceived of in each accepted paradigm of physics: Newtonian, special relativity, quantum mechanics (QM) and general relativity (GR). Substantial differences are moreover uncovered between what is meant by time in QM and in GR. These differences jointly source the Problem of Time: Nine interlinked facets which arise upon attempting concurrent treatment of the QM and GR paradigms, as is required in particular (...) for a background independent theory of quantum gravity. A sizeable proportion of current quantum gravity programs - e.g. geometrodynamical and loop quantum gravity approaches to quantum GR, quantum cosmology, supergravity and M-theory - are background independent in this sense. This book's foundational topic is thus furthermore of practical relevance in the ongoing development of quantum gravity programs. This book shows moreover that eight of the nine facets of the Problem of Time already occur upon entertaining background independence in classical (rather than quantum) physics. By this development, and interpreting shape theory as modelling background independence, this book further establishes background independence as a field of study. Background independent mechanics, as well as minisuperspace (spatially homogeneous) models of GR and perturbations thereabout are used to illustrate these points. As hitherto formulated, the different facets of the Problem of Time greatly interfere with each others' attempted resolutions. This book explains how, none the less, a local resolution of the Problem of Time can be arrived at after various reconceptualizations of the facets and reformulations of their mathematical implementation. Self-contained appendices on mathematical methods for basic and foundational quantum gravity are included. Finally, this book outlines how supergravity is refreshingly different from GR as a realization of background independence, and what background independence entails at the topological level and beyond. (shrink)

Bernat argues for a unified brain-based determination of death (UBDD), noting that it “conceptually justifies” death determination both in Donation after Circulatory Determination of Death (DCDD) a...

In the film “Kaili Blues” by Bi Gan, intricate clues create complex connections between the plots steered by various characters. This relationship manifests in splitting time and alternating between dream and reality. This article analyzes Bi Gan’s approach to temporality and dreams by focusing on how he employs various film metaphors to deal with poetic narratives in his films. The article consists of three sections: First, it introduces the (puzzle) storytelling form of “Kaili Blues” as a promising area in many (...) Chinese films. Second, it examines how puzzle films contribute to the ambiguity (plots) between characters from the perspective of infinite games. Moreover, third, the article discusses the two levels of metaphors in “Kaili Blues” that result from the condensation and displacement of metaphors, including the mutual projection of roles caused by the time-forking effect and the audience’s associations caused by the significance of dreams in Chinese tradition (or local) culture. (shrink)

When entering an environment, animals – including humans – tend to consult their memories to determine what they know about the place. This information is useful to determine: is this place safe? And what happens next? In this chapter, we argue on both empirical and conceptual grounds that memory is largely organized by space. Spatial relations determine what is recalled and which experiences are combined in generalizations. Time does not play an analogous role. We show that space and time in (...) memory are thus deeply asymmetrical. We conclude with a consequence of our view: spatial organization entails a basic form of abstraction in a way temporal organization does not, and so the spatial organization of memory reveals that memory involves generalization from the very beginning. (shrink)

The problem of time involves an overlap between physics, philosophy, psychology and neuroscience. My talk will discuss the role of time in physics but also emphasize that physics may need to expand to address issues usually regarded as being in the other domains. I will first review the mainstream physics view of time, as it arises in Newtonian theory, relativity theory and quantum theory. I will then discuss the various arrows of time, the most fundamental of which is the passage (...) of time associated with consciousness. I will argue that this goes beyond both relativity theory and quantum theory, so that one needs some new physical paradigm to accommodate it. A new paradigm is required anyway to describe quantum gravity and this may elucidate the nature of both time and consciousness. (shrink)

This philosopher’s introduction to the nature of time could radically alter how you see your past and imagine your future.

The `problem of time' is a cluster of interpretational and formal issues in the foundations of general relativity relating to both the representation of time in the classical canonical formalism, and to the quantization of the theory. The purpose of this short chapter is to provide an accessible introduction to the problem.

This is an invited commentary on "Physical Time within Human Time" (Gruber, Block, & Montemayor, 2022) and "Bridging the Neuroscience and Physics of Time" (Buonomano & Rovelli, 2021). I’m very sympathetic to aspects of each proposal. In this article, I offer some comments, starting with (Buonomano & Rovelli, 2021).

We find the claim that time is not real in both western and eastern philosophical traditions. In what follows I will call the view that time does not exist temporal error theory. Temporal error theory was made famous in western analytic philosophy in the early 1900s by John McTaggart (1908) and, in much the same tradition, temporal error theory was subsequently defended by Gödel (1949). The idea that time is not real, however, stretches back much further than that. It is (...) common to hear it said that according to Buddhist philosophy (as though that were a monolithic view) time is illusory. While it is not true that, in general, either contemporary or ancient Buddhist scholars have thought time to be illusory, there are certainly some schools of Buddhist thought, such as that of traditional Dzogchen practitioners, according to which there is no time. This paper is an attempt to set out a taxonomy of different views about what it takes for there to be time and, alongside that, a taxonomy of views about whether there is time or not, and if there is time what it is like. (shrink)

This is a new edition, revised and expanded, of a seminal work in the logic and philosophy of time, originally published in 1968. Arthur N. Prior was the founding father of temporal logic. His work has attracted increased attention in the decades since his death: its influence stretches beyond philosophy and logic to computer science and formal linguistics. Prior's fundamental ideas about the logic of time are presented here along with his investigations into the formal properties of time and tense. (...) Already in 1969 Prior had been planning a new edition of Papers on Time and Tense, to incorporate his more recent work. Because of his untimely death this plan was never followed through--till now. Seven important papers have been added to the original selection, as well as a comprehensive bibliography of his work and an illuminating interview with his widow, Mary Prior, about his life and work. In addition, the Polish logic which made the original book difficult for many readers has been replaced by standard logical notation. This new edition will secure the classic status of the book. (shrink)

This article proposes an interpretation of the ‘Thesis that Things do not Shift’ (_Wu bu qian lun,_ 物不遷論) of the early Chinese Buddhist philosopher Sengzhao. We understand Sengzhao to be proposing a version of the philosophy of time found in Sarvāstivāda Abhidharma, and then interpreting statements about time from Mahāyāna texts in light of that account. But whatever his limitations as a cross-cultural interpreter, we find Sengzhao surprisingly impressive philosophically, as he proposes a view that is noticeably more advanced towards (...) a modern conception of time than the accounts found in South Asian Buddhist sources. Ironically, his earnest efforts to present his view as falling within the Mahāyāna may have functioned to conceal Sengzhao’s true philosophical achievement. (shrink)

Justice is usually represented as a feminine figure holding a pair of scales and a sword. The history of that image is relatively recent and has attracted a great deal of attention. However, a different appreciation of it may come from a “nocturnal” jurisprudence seeking to foreground its presence and effects in the transmission of modern culture and so also of law. In this essay, I take my cue from Aby Warburg and the Pathosformeln that, he suggested, can be glimpsed (...) through certain material objects inherited from the past—specifically, Dürer’s The Death of Orpheus and other related visual art. I then consider what Giorgio Agamben calls ‘the image of the image’ emphasising the timely quality of those images and I ask, with Georges Didi-Huberman, whether it might not be high time to “return” that which those images ostensibly show. The associations established in this essay between those different insights may help to recognise the extent to which the innumerable images to do with justice found at the four corners of the world can make the cognitive and emotional experience of those encountering them a rather more complex and potentially problematic affair than it may be at first supposed. What, on closer inspection, can those images give us to see? Are the ancient configurations they sometimes transmit not made up of crystals of historical memory carrying dormant energies that could be suddenly reignited in unpredictable ways? Should the task ahead not be, in some cases, one of restitution—the inapparent gift that turns the “blotted-out” into something striking that can be then handed over and known? These, I argue, are some of the questions a “nocturnal” jurisprudence of the image can be about. (shrink)

Frequently Asked Questions about Time This supplement provides background information about many of the topics discussed in both the main Time article and its companion article What Else Science Requires of Time. It is not intended that this article be read in order by section number. Table of Contents What Are Durations, Instants, Moments, and … Continue reading Frequently Asked Questions about Time →.

The Evolving Block Universe is a model where spacetime continuously emerges leading to a ‘growth’ of spacetime by which there is a passage of time. Its most recent version extends ideas on the passage of time and the various arrows of time (determined by the cosmological evolution of the whole universe). Attention is drawn to some principal problems with this model, especially how the present moment and the passage of time are defined.