David Wallace argues that we should take quantum theory seriously as an account of what the world is like--which means accepting the idea that the universe is constantly branching into new universes. He presents an accessible but rigorous account of the 'Everett interpretation', the best way to make coherent sense of quantum physics.

First published in 1903, _Principles of Mathematics_ was Bertrand Russell’s first major work in print. It was this title which saw him begin his ascent towards eminence. In this groundbreaking and important work, Bertrand Russell argues that mathematics and logic are, in fact, identical and what is commonly called mathematics is simply later deductions from logical premises. Highly influential and engaging, this important work led to Russell’s dominance of analytical logic on western philosophy in the twentieth century.

This concise book introduces nonphysicists to the core philosophical issues surrounding the nature and structure of space and time, and is also an ideal resource for physicists interested in the conceptual foundations of space-time theory. Tim Maudlin's broad historical overview examines Aristotelian and Newtonian accounts of space and time, and traces how Galileo's conceptions of relativity and space-time led to Einstein's special and general theories of relativity. Maudlin explains special relativity using a geometrical approach, emphasizing intrinsic space-time structure rather than (...) coordinate systems or reference frames. He gives readers enough detail about special relativity to solve concrete physical problems while presenting general relativity in a more qualitative way, with an informative discussion of the geometrization of gravity, the bending of light, and black holes. Additional topics include the Twins Paradox, the physical aspects of the Lorentz-FitzGerald contraction, the constancy of the speed of light, time travel, the direction of time, and more.Introduces nonphysicists to the philosophical foundations of space-time theory Provides a broad historical overview, from Aristotle to Einstein Explains special relativity geometrically, emphasizing the intrinsic structure of space-time Covers the Twins Paradox, Galilean relativity, time travel, and more Requires only basic algebra and no formal knowledge of physics. (shrink)

This paper has three main sections. The first section provides a general characterisation of presentism, eternalism and growing blockism. It presents a pair of core, defining claims that jointly capture each of these three views. This makes clear the respects in which the different views agree, and the respects in which they disagree, about the nature of time. The second section takes these characterisations and considers whether we really do have three distinct views, or whether defenders of these views are (...) somehow talking past one another when they claim to disagree. The third section looks at the key objections to each view and considers some of the replies that can be made to those objections. The paper concludes by offering some thoughts about how future research might help us resolve the debate between defenders of these three views. (shrink)

First published in 2002. Routledge is an imprint of Taylor & Francis, an informa company.

There is a common form of problem, to be found in many areas of philosophy, concerning the relationship between our perspective on reality and reality itself. We make statements (or form judgements) about how things are from a given standpoint or perspective. We make the statement ‘it is raining’ from the standpoint of the present time, for example, or the statement‘it is here’ from the standpoint of where we are, or the statement ‘I am glad’ from the standpoint of a (...) subject. In each of these cases, the statement has a certain ‘aspect’ or perspectival character in virtue of which its truth is capable of varying from one standpoint to another. Thus the statement ‘it is raining’ is tensed, the statement ‘it is here’ is ‘spatiocentric’ and the statement ‘I am glad’ is first-personal. The problem we then face is to determine whether this aspect is a feature of the reality which is described or merely a feature of the statement by which it is described. Is reality itself somehow tensed or spatiocentric or firstpersonal or is it merely that we describe a tenseless or spatially uncentered or impersonal reality from a tensed or spatiocentric or first-personal point of view? (shrink)

This paper is about The Truthmaker Problem for Presentism. I spell out a solution to the problem that involves appealing to indeterministic laws of nature and branching semantics for past- and future-tensed sentences. Then I discuss a potential glitch for this solution, and propose a way to get around that glitch. Finally, I consider some likely objections to the view offered here, as well as replies to those objections.

We address the question of whether it is possible to operate a time machine by manipulating matter and energy so as to manufacture closed timelike curves. This question has received a great deal of attention in the physics literature, with attempts to prove no- go theorems based on classical general relativity and various hybrid theories serving as steps along the way towards quantum gravity. Despite the effort put into these no-go theorems, there is no widely accepted definition of a time (...) machine. We explain the conundrum that must be faced in providing a satisfactory definition and propose a resolution. Roughly, we require that all extensions of the time machine region contain closed timelike curves; the actions of the time machine operator are then sufficiently "potent" to guarantee that closed timelike curves appear. We then review no-go theorems based on classical general relativity, semi-classical quantum gravity, quantum field theory on curved spacetime, and Euclidean quantum gravity. Our verdict on the question of our title is that no result of sufficient generality to underwrite a confident "yes" has been proven. Our review of the no-go results does, however, highlight several foundational problems at the intersection of general relativity and quantum physics that lend substance to the search for an answer. (shrink)

This article provides a non-technical overview of the conflict between the special theory of relativity and the dynamic theories of time. The chief argument against dynamic theories of time from relativistic mechanics is presented. The space of current responses to that argument is subsequently mapped.

According to presentism, only the present exists. The view is in a bad dialectical situation since it has to face several objections based on physics and a priori arguments. The view remains nonetheless popular because it is, allegedly, more intuitive than alternative views, namely eternalism (past, present and future entities exist) and no-futurism (only past and present entities exist). In the essay, I shall not discuss whether intuitivity is an accurate criterion for ontological enquiry. I will rather argue that any (...) philosophically acceptable version of presentism entails highly counterintuitive consequences. Indeed, the presentist has to commit herself to substantial claims in order to provide an answer to two problems : the grounding problem and the cross-temporal relations problem. Therefore, if the main motivation for presentism is the willingness to stick with common sense intuitions, presentists should consider endorsing another view about existence in time. (shrink)

According to no-futurism, past and present entities are real, but future ones are not. This view faces a skeptical challenge (Bourne 2002, 2006, Braddon-Mitchell, 2004): if no-futurism is true, how do you know you are present? I shall propose a new skeptical argument based on the physical possibility of Gödelian worlds (1949). This argument shows that a no-futurist has to endorse a metaphysical contingentist reading of no-futurism, the view that no-futurism is contingently true. But then, the no-futurist has to face (...) a new skeptical challenge: how do you know that you are in a no-futurist world? (shrink)

This chapter discusses the notion that time passes, along with two major families of objections to this notion. The first kind of objection concerns the rate at which time passes; it has often been suggested that no coherent rate can be given. The alleged problems for the standard view, that time passes at one second per second, are discussed. A positive suggestion is then made for a way of making sense of the claim that time passes at one second per (...) second, based on the notion of ‘stretching’ properties such as ‘being future’ across a time series made up of events. The second family of objections concerns the experience of time passing. Two arguments are discussed, one of which concerns epistemological issues while the other concerns the intentionality of experience. Overall the arguments from experience weigh against the passage of time. (shrink)

I begin by giving reasons to accept the block-universe view, the strongly supported by physics view that we live in a four-dimensional world. According to it, the past and the future are as real as the present. As a result, it seems that the future is determined in the sense that what will be the case will necessarily be the case. In the dissertation, I examine whether we have to accept this consequence. I show that we do not have to (...) bite the bullet: the future might be both real and contingent. I first start to consider modal realism (possible futures are real) as a possible solution. However, I propose then another account, actualist (positing the reality of only one possible world: the space-time we live in). This solution relies on a conventionalist theory about metaphysical modality (Sidelle, 1989). It states that modal modality is purely conventional. In combination with a realist interpretation of natural modality (causal and/or nomological), this framework allows me to propose that the future is conventionally closed and naturally contingent. In this view, the necessity of the future holds in virtue of linguistic conventions and then is conventionally necessary. But this is a distinct phenomenon from the natural contingency of the future: the future is naturally contingent because there are mind-independent probabilistic relations holding between the present and the future. This solution has strong consequences: most importantly, an anti-realist view about ordinary objects and physical particles. I end up by presenting and arguing in favour of the general image of the world that comes out from these views. (shrink)

Le temps est une notion associée aux changements, qu’ils soient futiles ou existentiels. Il permet ainsi l’organisation moderne de nos sociétés à travers les agendas, la planification du travail ou les rendez-vous galants. Il rythme les saisons et nous expérimentons chaque année les couleurs chatoyantes de l’automne et les nuages sombres de l’hiver. Notre corps évolue constamment et vieillit sans cesse entre notre naissance passée et notre mort future. Toutes ces descriptions font intervenir le concept de temps, ou une notion (...) plus spécifique généralement associée au temps comme le changement, le passé, le présent, le futur, la simultanéité ou la synchronisation. Mais quelle est la nature du temps ? Que peut-on comprendre de cette notion si fondamentale et si présente dans notre vie quotidienne, et pourtant si difficilement définissable ? Cet article vise à introduire les différentes conceptions contemporaines du temps objectif, indépendamment des perceptions que nous en avons. Le temps existe-t-il (section 1.) ? Le temps s’écoule-t-il (section 2.) ? Le passé et le futur existent-ils (section 3.) ? Le présent possède-t-il une étendue (section 4.) ? Le futur est-il déjà écrit maintenant (section 5.) ? Le temps est-il une substance qui contient les objets matériels, ou une collection de relations entre les objets matériels (section 6.) ? Quelle est la source de la direction apparente du temps (section 7.) ? Peut-on voyager dans le temps (section 8.) ? Ces questions seront présentées sous un angle contemporain. (shrink)

Sometimes, I like to write 'philosophical stories' that explain a philosophical problem, and this book is a compilation of five such stories. So this is a book for non-philosophers or for beginners in philosophy. There is a story of a bald punk that allows me to explain theories of vagueness, a story about brains in vats that gives rise to a discussion of scepticism about the external world, a story about a theft in a museum where the thief is condemned (...) twice (once for stealing a statue, and once for stealing a piece of bronze of which the statue was made), a time travel story, and a ship od Theseus revisited story. I hope to have achieved something that is both fun and serious and that will give a good picture of what philosophy is to the general public. The book is also intented for first or second year philosophy students, who can find there a starting point for understanding some debates. (shrink)