În această lucrare analizez posibilitatea călătoriei în timp pe baza mai multor lucrări de specialitate, printre care cele ale lui Nicholas J.J. Smith ("Time Travel", The Stanford Encyclopedia of Philosophy”), William Grey (”Troubles with Time Travel”), Ulrich Meyer (”Explaining causal loops”), Simon Keller și Michael Nelson (”Presentists should believe in time-travel”), Frank Arntzenius și Tim Maudlin ("Time Travel and Modern Physics") și David Lewis (“The Paradoxes of Time Travel”). Lucrarea începe cu o Introducere în care fac o scurtă prezentare a (...) călătoriei în timp, și continuă cu o Istoria conceptului de călătorie în timp, prezentarea principalelor Aspecte fizice ale călătoriei în timp, inclusiv călătoria în timp în trecut în relativitatea generală și în fizica cuantică și călătoria în timp în viitor, apoi o prezentare a Paradoxul bunicului care este abordat în aproape toate lucrările de specialitate, urmat de o secțiune dedicată Filosofiei călătoriei în timp, și o secțiune în care analizez Buclele cauzale pentru călătoria în timp. Finalizez lucrarea cu Concluzii, în care expun opiniile personale privind călătoria în timp, și Bibliografia pe care se bazează lucrarea. (shrink)

The doctrine of the immaculate conception, which is a dogma binding on all Roman Catholics and also held by members of some other Christian denominations, holds that Mary the mother of Jesus Christ was conceived without the stain of original sin as a result of the redeeming effects of Christ’s later life, passion, death, and resurrection. In this paper I argue first that, even on an orthodox reading of this doctrine, the immaculate conception seems to result in a kind of (...) causal time loop. I then consider several common philosophical objections to causal time loops, showing how each is either not a serious problem for causal time loops in general or is not a serious problem for the immaculate conception time loop in particular because of some particular features of that particular loop. The upshot of this discussion is that it shows that anyone who is committed to the dogma of the immaculate conception is also committed to the possibility, and, indeed, the actuality, of at least one causal time loop, but also that this is no reason to reject the dogma, since all of the major worries for causal time loops can be resolved in one way or another. (shrink)

It is not uncommon in time travel stories to find that the mechanism by which the time travel is achieved is not invented. A time traveller could journey to his/her own past and give the designs of the time travel machine to his/her earlier self as s/he was given the designs as a younger person. These designs never get thought up by anyone. Such a situation would conflict with the usual conception of the acquisition of knowledge. This situation is called (...) the Temporal Epistemic Anomaly and would arise if knowledge is gained at a time prior to the information in question being transmitted but is not discovered or invented at any time. This article examines the implications of information propagating around a causal chain that is closed in time (which is required to create the Anomaly) and whether this information need have a specific origin point. (shrink)

In 1987, Roy Sorensen coined the term “parahistory” to denote the hypothetical study of evidence retrieved via time travel. Parahistory would thus stand to history rather as parapsychology does to psychology; studying data (in this case artefacts) that are obtained in ways unrecognised by orthodox science. This paper considers future-derived parahistorical artefacts. Past/future asymmetries threaten irresolvable problems in calibrating future objects' periods, in dating future artefacts and insulating them from causal loops. In turn, causal loop objects at best cannot be (...) non-arbitrarily dated at all and at worst, cannot even be artefacts. Even if there can be evidence for travel from the future, any such evidence that appeals to future artefacts faces pervasive difficulties and is very unlikely to be compelling. (shrink)

In 1987, Roy Sorensen coined the term “parahistory” to denote the hypothetical study of evidence retrieved via time travel. Parahistory would thus stand to history rather as parapsychology does to psychology; studying data (in this case artefacts) that are obtained in ways unrecognised by orthodox science. This paper considers future-derived parahistorical artefacts. Past/future asymmetries threaten irresolvable problems in calibrating future objects' periods, in dating future artefacts and insulating them from causal loops. In turn, causal loop objects at best cannot be (...) non-arbitrarily dated at all and at worst, cannot even be artefacts. Even if there can be evidence for travel from the future, any such evidence that appeals to future artefacts faces pervasive difficulties and is very unlikely to be compelling. (shrink)

This paper outlines a new method for identifying folk intuitions to complement armchair intuiting and experimental philosophy, and thereby enrich the philosopher’s toolkit. This new approach—trope analysis—depends not on what people report their intuitions to be but rather on what they have made and engaged with; I propose that tropes in fiction reveal which theories, concepts and ideas we find intuitive, repeatedly and en masse. Imagination plays a dual role in both existing methods and this new approach: it enables us (...) to create the scenarios that elicit our intuitions, and also to mentally represent them. The method I propose allows us to leverage the imagination of the many rather than the few on both counts—scenarios are both created and consumed by the folk themselves. (shrink)

Causal loops are a recurring feature in the philosophy of time travel, where it is generally agreed that they are logically possible but may come with a theoretical cost. This paper introduces an unfamiliar set of causal loop cases involving knowledge or beliefs about the future: self-fulfilling prophecy loops (SFP loops). I show how and when such loops arise and consider their relationship to more familiar causal loops.

It has sometimes been suggested that backwards time travel always incurs causal loops. I show that this is mistaken, by describing worlds where backwards time travel occurs and yet no causal loops occur. Arguments that backwards time travel can occur without causal loops have been given before in the literature, but I show that those arguments are unconvincing.

Brit J Aesthetics DOI:_ 10.1093/aesthj/ayz041 _.

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)

The philosophy of time travel is a sub-field of metaphysics – the study of what there is and what things are like – that considers questions about the possibility of time travel and what a world in which time travel is possible looks like. These questions range from whether time travel is actually possible, to how time travellers can act in the past or future. This thesis delves into a particularly interesting, yet historically undertreated theme: the abilities of time travellers (...) and relatedly their freedom as well. The abilities and freedom of time travellers has been the source of a lot of recent discussion with some polarising views. The minority (which includes Lewis (1976), but also Ted Sider (2002)) argue for the affirmative – that time travellers are free and have the same (or perhaps more) abilities as non-time travellers. The majority (which includes Kadri Vihvelin (1996), Michael Rea (2005), Stephanie Rennick (2015), Alison Fernandes (2020), amongst others) argue for the negative, that time travellers do not have exactly the same freedoms and abilities as non-time travellers. I think that it is a mistake to be so pessimistic about the abilities and freedom of time travellers. I treat concerns about the freedom of time travellers and concerns about the abilities of time travellers as two sides of the same coin. Therefore, in what follows, I argue for two related conclusions. First, I argue that time travellers have all sorts of abilities. Second, I argue that time travellers are just as free as non-time travellers. In arguing for these conclusions, I first produce a novel analysis of ability which reveals important details about how abilities track inputs rather than outputs. Second, I use this new analysis of ability to present a new compatibilist account of free will. If I am right in arguing positively for the abilities and freedoms of time travellers, then this has large implications for both the current time travel discourse and the general debate surrounding freedom. Significantly, I am arguing against some prominent views about time travel and in suggesting that these views are mistaken, I am presenting new ideas about ability and freedom: specifically, that time travellers have the ability and are free to do impossible things. (shrink)

Some facts ground other facts. Some fact is fundamental iff there are no other facts which partially or fully ground that fact. According to metaphysical foundationalism, every non-fundamental fact is fully grounded by some fundamental fact(s). In this paper I examine and defend some neglected considerations which might be made in favor of metaphysical foundationalism. Building off of work by Ross Cameron, I suggest that foundationalist theories are more unified than, and so in one important respect simpler than, non-foundationalist theories, (...) insofar as foundationalist theories allow us to derive all non-fundamental facts from some fundamental fact(s). Non-foundationalist theories can enjoy a similar sort of theoretical unification only by taking on objectionable metaphysical laws. (shrink)

The following is a critical and historical account of Aristotelian Essentialism informed by recent work on Aristotle’s modal syllogistic. The semantics of the modal syllogistic are interpreted in a way that is motivated by Aristotle, and also make his validity claims in the Prior Analytics consistent to a higher degree than previously developed interpretative models. In Chapter One, ancient and contemporary objections to the Aristotelian modal syllogistic are discussed. A resolution to apparent inconsistencies in Aristotle’s modal syllogistic is proposed and (...) developed out of recent work by Patterson, Rini, and Malink. In particular, I argue that the semantics of negation is distinct in modal context from those of assertoric negative claims. Given my interpretive model of Aristotle’s semantics, in Chapter Two, I provide proofs for each of the mixed apodictic syllogisms, and propose a method of using Venn Diagrams to visualize the validity claims Aristotle makes in the Prior Analytics. Chapter Three explores how Aristotle’s syllogistic fits within Aristotle’s philosophy of science and demonstration, particularly within the context of the Posterior Analytics. Consideration is given to the Aristotelian understanding of the relationship among necessity, explanation, definition, and essence. Chapter Four applies Aristotelian modal logic in contemporary contexts. I contrast Aristotelian modality and essentialism with contemporary modalism based upon the semantics of possible worlds, e.g. Kripke and Putnam. I also develop an account of how Aristotelian modal logic can ground a sortal dependent theory of identity, as discussed by Wiggins. (shrink)

À propos de la possibilité de voyager dans le temps sur la base de plusieurs ouvrages spécialisés, notamment ceux de Nicholas J. J. Smith (« Time Travel »), William Grey (« Troubles with Time Travel »), Ulrich Meyer (« Explaining causal loops »), Simon Keller and Michael Nelson (« Presentists should believe in time-travel »), Frank Arntzenius and Tim Maudlin (« Time Travel and Modern Physics »), et David Lewis (« The Paradoxes of Time Travel »). L'article commence par une (...) Introduction dans laquelle je fais une brève présentation du voyage dans le temps et poursuit par une Histoire du concept de voyage dans le temps, les principaux aspects physiques du voyage dans le temps, y compris les voyages dans le temps dans le passé dans la relativité générale et la physique quantique , et les voyages dans le temps dans le futur, puis une présentation du Paradoxe du grand-père abordé dans presque toutes les œuvres spécialisées, suivie d’une section consacrée à la Philosophie du voyage dans le temps et d’une section dans laquelle j’analyse les Boucles causales pour le voyage dans le temps. Je termine mon travail avec Conclusions, dans laquelle je maintiens mes opinions personnelles sur le voyage dans le temps et la Bibliographie sur laquelle repose le travail. -/- TABLE: -/- Abstract Introducere Istoria conceptului de călătorie în timp Paradoxul bunicului Filosofía călătoriei în timp Buclele cauzale Concluzii Note Bibliografie -/- DOI: 10.13140/RG.2.2.27116.51841. (shrink)

There is, among some scientists and philosophers, the idea that any theory that would allow the time travel would introduce causal issues. These types of temporal paradoxes can be avoided by the Novikov self-consistency principle or by a variation in the interpretation of many worlds with interacting worlds. The world in which we live has, according to David Lewis, a Parmenidean ontology: "a manifold of events in four dimensions," and the occupants of the world are the 4-dimensional aggregates of the (...) stages - "temporal lines". The causal loops in backwards time travel involve events that appear to "come from nowhere," paradoxical "self-existent" objects or information, resulting in a bootstrap paradox. Many believe that causality loops are not impossible or unacceptable, but only inexplicable. DOI: 10.13140/RG.2.2.28792.70407. (shrink)