This paper scrutinises the tenability of a strict conceptual distinction between space and matter via the lens of the debate between modified gravity and dark matter. In particular, we consider Berezhiani and Khoury's novel 'superfluid dark matter theory' as a case study. Two families of criteria for being matter and being spacetime, respectively, are extracted from the literature. Evaluation of the new scalar field postulated by SFDM according to these criteria reveals that it is as much matter as anything could (...) possibly be, but alsoꟷbelow the critical temperature for superfluidityꟷas much spacetime as anything could possibly be. A sequel paper examines possible interpretations of SFDM in light of this result, as well as the consequences for our understanding of the modified gravity/ dark matter distinction and the broader spacetime–matter distinction. (shrink)

I discuss the relationship between different versions of the equivalence principle in general relativity, among them Einstein's equivalence principle, the weak equivalence principle, and the strong equivalence principle. I show that Einstein's version of the equivalence principle is intimately linked to his idea that in GR gravity and inertia are unified to a single field, quite like the electric and magnetic field had been unified in special relativistic electrodynamics. At the same time, what is now often called the strong equivalence (...) principle, related to the local validity of special relativity, can also be found in Einstein's writings, albeit by a different name and clearly separated from what he calls the equivalence principle. I discuss both the development of Einstein's thoughts on the different versions of the equivalence principle, their relationship to the relativity principle, as well as later reflections and variants proposed. (shrink)

Recent decades have seen a revived interest in super-substantivalism, the idea that spacetime is the only fundamental substance and matter some kind of aspect, property or consequence of spacetime structure. However, the metaphysical debate so far has misidentified a particular variant of super-substantivalism with the position per se. I distinguish between a super-substantival core commitment and different ways of fleshing it out. I then investigate how general relativity and alternative spacetime theories square with the different variants of super-substantivalism.

I argue that, contrary to folklore, Einstein never really cared for geometrizing the gravitational or the electromagnetic field; indeed, he thought that the very statement that General Relativity geometrizes gravity "is not saying anything at all". Instead, I shall show that Einstein saw the "unification" of inertia and gravity as one of the major achievements of General Relativity. Interestingly, Einstein did not locate this unification in the field equations but in his interpretation of the geodesic equation, the law of motion (...) of test particles. (shrink)

I describe how relativistic field theory generalizes the paradigm property of material systems, the possession of mass, to the requirement that they have a mass–energy–momentum density tensor T µ associated with them. I argue that T µ does not represent an intrinsic property of matter. For it will become evident that the definition of T µ depends on the metric field g µ in a variety of ways. Accordingly, since g µ represents the geometry of spacetime itself, the properties of (...) mass, stress, energy, and momentum should not be seen as intrinsic properties of matter, but as relational properties that material systems have only in virtue of their relation to spacetime structure. (shrink)

The problem of motion in general relativity is about how exactly the gravitational field equations, the Einstein equations, are related to the equations of motion of material bodies subject to gravitational fields. This article compares two approaches to derive the geodesic motion of matter from the field equations: the ‘T approach’ and the ‘vacuum approach’. The latter approach has been dismissed by philosophers of physics because it apparently represents material bodies by singularities. I argue that a careful interpretation of the (...) approach shows that it does not depend on introducing singularities at all and that it holds at least as much promise as the T approach. (shrink)

Einstein regarded as one of the triumphs of his 1915 theory of gravity - the general theory of relativity - that it vindicated the action-reaction principle, while Newtonian mechanics as well as his 1905 special theory of relativity supposedly violated it. In this paper we examine why Einstein came to emphasise this position several years after the development of general relativity. Several key considerations are relevant to the story: the connection Einstein originally saw between Mach's analysis of inertia and both (...) the equivalence principle and the principle of general covariance, the waning of Mach's influence owing to de Sitter's 1917 results, and Einstein's detailed correspondence with Moritz Schlick in 1920. (shrink)

"Williams's masterful translation satisfies (at last!) a long-standing need. There are lots of good translations of Augustine's great work, but until now we have been forced to choose between those that strive to replicate in English something of the majesty and beauty of Augustine's Latin style and those that opt instead to convey the careful precision of his philosophical terminology and argumentation. Finally, Williams has succeeded in capturing both sides of Augustine's mind in a richly evocative, impeccably reliable, elegantly readable (...) presentation of one of the most impressive achievements in Western thought--Augustine's Confessions." --Scott MacDonald, Professor of Philosophy and Norma K. Regan Professor in Christian Studies, Cornell University. (shrink)

This contributed volume is the result of a July 2010 workshop at the University of Wuppertal Interdisciplinary Centre for Science and Technology Studies which brought together world-wide experts from physics, philosophy and history, in order to address a set of questions first posed in the 1950s: How do we compare spacetime theories? How do we judge, objectively, which is the “best” theory? Is there even a unique answer to this question? -/- The goal of the workshop, and of this book, (...) is to contribute to the development of a meta-theory of spacetime theories. Such a meta-theory would reveal insights about specific spacetime theories by distilling their essential similarities and differences, deliver a framework for a class of theories that could be helpful as a blueprint to build other meta-theories, and provide a higher-level viewpoint for judging which theory most accurately describes nature. But rather than drawing a map in broad strokes, the focus is on particularly rich regions in the “space of spacetime theories.” -/- This work will be of interest to physicists, as well as philosophers and historians of science working with or interested in General Relativity and/or Space, Time and Gravitation more generally. (shrink)

It is often claimed that relativity theory falls short of giving an account of 'the flow of time' and 'the arrow of time'. Some claim that hence either one or both of these concepts do not correspond to objective reality, others infer that relativity theory is wrongfully 'spatialising' time. I investigate of our normal conception of time is enduring in relativity, even in the absence of a clear representation of flow. It is shown that the conformal structure of spacetime allows (...) for a clear distinction between past, present and future, and that the class of temporally orientable spacetimes allows for an 'arrow of time'. Finally, I briefly discuss the class of Friedmann universes, to which our universe seems to belong, and which is indeed temporally orientable. German Es wird häufig behauptet, dass die Relativitätstheorie keine adäquate Beschreibung des , Zeitflusses' und des , Zeitpfeils' enthalte. Einige ziehen daraus die Schlussfolgerung, dass beiden Konzepten nichts in der objektiven Realität entspreche, andere ziehen den Schluss, dass die Relativitätstheorie die Zeit fälschlicherweise , verräumliche'. Ich untersuche, wie viel von unserer althergebrachten Zeitvorstellung in der Relativitätstheorie überdauert, selbst in der Abwesenheit einer klaren Repräsentation von , Zeitfluss'. Ich zeige, dass die konforme Struktur der Raumzeit eine klare Unterscheidung von Vergangenheit, Gegenwart und Zukunft erlaubt, und dass die Klasse der zeitlich orientierbaren Raumzeiten die Repräsentation einer , Zeitpfeils' durchaus erlaubt. Schließlich diskutiere ich kurz die Klasse der Friedmann Raumzeiten, zu welcher unser Universum zu gehören scheint, und welches tatsächlich zeitlich orientierbar ist. (shrink)

The best available introduction to the political thought of Augustine, if not to Christian political thought in general. Included are generous selections from _City of God_, as well as from many lesser-known writings of Augustine.

This paper pushes back against the Democritean-Newtonian tradition of assuming a strict conceptual dichotomy between spacetime and matter. Our approach proceeds via the more narrow distinction between modified gravity/spacetime and dark matter. A prequel paper argued that the novel field Φ postulated by Berezhiani and Khoury's 'superfluid dark matter theory' is as much matter as anything could possibly be, but also below the critical temperature for superfluidity as much spacetime as anything could possibly be. Here we introduce and critically evaluate (...) three groups of interpretations that one should consider for such Janus-faced theories. The consubstantiality interpretation holds that Φ is both matter and a modification of spacetime, analogously to the sense in which Jesus is both human and god. The fundamendalist interpretations consider for each of these roles whether they are instantiated fundamentally or emergently. The breakdown interpretations focus on the question of whether Φ signals the breakdown, in some sense to be specified, of the MG-DM dichotomy and perhaps even the broader spacetime–matter distinction. More generally, it is argued that hybrid theories urge a move towards a single space of theories, rather than two separate spaces of spacetime theories and matter theories, respectively. (shrink)

_A fresh, new translation of Augustine’s third work as a Christian convert__ "The 'Cassiciacum dialogues'... are of a high literary and intellectual quality, combining Ciceronian and neo-Platonic philosophy, Roman comedy and Vergilian poetry, and early Christian theology. They are also, arguably, Augustine’s most charming works, exhibiting his whimsical levity and ironic wryness."—_Credo__ The first four works written by St. Augustine of Hippo after his conversion to Christianity are dialogues that have influenced prominent thinkers from Boethius to Bernard Lonergan. Usually called (...) the “Cassiciacum dialogues,” these four works are of a high literary and intellectual quality, combining Ciceronian and neo-Platonic philosophy, Roman comedy and Vergilian poetry, and early Christian theology. They are also, arguably, Augustine’s most charming works, exhibiting his whimsical levity and ironic wryness. _On Order_ is the third work in this tetralogy, and it is Augustine’s only work explicitly devoted to theodicy, the reconciliation of Almighty God’s goodness with evil’s existence. In this dialogue, Augustine argues that a certain kind of self-knowledge is the key to unlocking the answers to theodicy’s vexing questions, and he devotes the latter half of the dialogue to an excursus on the liberal arts as disciplines that will help strengthen the mind to know itself and God. (shrink)

_A fresh, new translation of Augustine’s fourth work as a Christian convert_ The first four works written by St. Augustine of Hippo after his conversion to Christianity are dialogues that have influenced prominent thinkers from Boethius to Bernard Lonergan. Usually called the Cassiciacum dialogues, these four works are of a high literary and intellectual quality, combining Ciceronian and neo-Platonic philosophy, Roman comedy and Vergilian poetry, and early Christian theology. They are also, arguably, Augustine’s most charming works, exhibiting his whimsical levity (...) and ironic wryness. _Soliloquies_ is the fourth work in this tetralogy. Augustine coined the term “soliloquy” to describe this new form of dialogue. _Soliloquies__,_ a conversation between Augustine and his reason, fuses the dialogue genre and Roman theater, opening with a search for intellectual and moral self-knowledge before converging on the nature of truth and the question of the soul’s immortality. Foley’s volume also includes _On the Immortality of the Soul__,_ which consists of notes for the unfinished portion of the work. (shrink)

We discuss three philosophically interesting epistemic peculiarities of black hole astrophysics: (1) issues concerning whether and in what sense black holes do exist; (2) how to best approach multiplicity of available definitions of black holes; (3) short (i.e., accessible within an individual human lifespan) dynamical timescales present in many of the recent, as well as prospective, observations involving black holes. In each case we argue that the prospects for our epistemic situation are optimistic.

Le concept de personne humaine joue sans aucun doute un rôle clé dans les débats bioéthiques de nos jours, notamment en ce qui concerne le début et la fin de la vie humaine. Les difficultés d’un recours à cette notion sont pourtant réelles, comme le montre l’opposition emblématique de deux penseurs, Peter Singer et Robert Spaemann, qui défendent des positions contraires quant à la relation entre l’appartenance à l’espèce humaine et le statut de personne. Par le biais d’une analyse de (...) leurs réflexions, nous remettrons en question la force argumentative de ce concept, puis nous proposerons une approche qui se base davantage sur la notion de « téléologie humaine ». (shrink)

En situant l’œuvre de Pannenberg comme une réponse à K. Barth et à la théologie dialectique, l’article analyse le renouvellement apporté au concept de révélation : non seulement l’histoire toute entière est révélation de Dieu, mais la résurrection du Christ anticipe de manière proleptique le sens et la fin de l’histoire. L’œuvre dogmatique de Pannenberg développe ces affirmations sans en négliger les conséquences anthropologiques.

La signification de la Torah pour l’éthique chrétienne se prête à trois perspectives différentes : la création divine, la rédemption en Christ, la sanctification par l’Esprit Saint. Selon la première approche, examinée à partir de Thomas d’Aquin, la Torah affirme que la « loi naturelle » est inscrite par le Créateur dans le coeur de l’homme. Selon la seconde, christologique, suivie dans les écrits de Luther, la relation créatrice se trouve reprise dans la dialectique Loi-Évangile, en évitant à la fois (...) des tendances antinomistes et légalistes. Dans la dernière perspective, pneumatologique, présente entre autres chez Barth et Bonhoeffer, la Torah est, toujours à nouveau, un « enseignement » qui forme le caractère du chrétien à l’image du Christ. Le « commandement concret » ne se découvre que dans la situation même de la décision, en tant que parole concrète de l’Esprit Saint. (shrink)

_A fresh, new translation of Augustine’s inaugural work as a Christian convert_ The first four works written by St. Augustine of Hippo after his conversion to Christianity have influenced prominent thinkers from Boethius to Bernard Lonergan. Usually called the Cassiciacum dialogues, these four works are a “literary triumph,” combining Ciceronian and neo-Platonic philosophy, Roman comedy and Vergilian poetry, and early Christian theology. They are also, arguably, Augustine’s most charming works, exhibiting his whimsical levity and ironic wryness. In this first dialogue, (...) Augustine and his interlocutors have retreated to a quiet country villa north of Milan to explore the history and teachings of Academic Skepticism. Augustine is both sympathetic to and critical of the Skeptics, eventually hypothesizing that they could not possibly have believed everything they taught. The dialogue serves as a fitting launch point for a knowledge of God and the soul, the overall subject of the Cassiciacum tetralogy. Michael Foley’s clear, precise and playful translations are accompanied by his brief, illuminating commentaries. (shrink)

In this book, Augustine Brannigan provides a critical examination of the major theories which have been devised to account for discoveries and innovations in ...

L’unité des disciplines théologiques n’est pas toujours facile à percevoir. L’étude des textes bibliques, d’une part, et la réflexion sys­tématique, d’autre part, suivent chacune leur logique et leurs méthodes, pour ne rien dire des disciplines historiques et pratiques ! Afin de répondre à la demande toujours grandissante d’une approche interdisciplinaire, les soussignés, tous deux enseignants à la Faculté de théologie protestante de l’Université Marc Bloch, l’un bibliste, l’autre éthicien, a..

Le rire est un phénomène qui touche aussi bien le corps que l’âme de l’homme. Helmuth Plessner l’interprète comme le signe d’une existence contradictoire propre à la condition humaine, une existence à la frontière, marquée par l’ambivalence de la relation corps-âme. Quant au comique, un des déclencheurs principaux du rire, la plupart des philosophes le décrivent aussi comme l’apparition d’une contradiction et d’une incongruité. Dans l’histoire de la théologie, le rire a souvent été critiqué ou même interdit. Par contre, le (...) Moyen-Age connaît une culture du comique et même une valorisation théologique du rire. Le rire du chrétien ne peut-il être compris comme expression de son existence contradictoire de pécheur et de justifié ? Placé « à l’extérieur de lui-même », en tant que pécheur gracié, le chrétien est désormais capable de rire. Laughter is a phenomenon that affects man’s body as well as his soul. Helmuth Plessner interprets it as the sign of the contradictory existence which is peculiar to the human condition, a border existence, marked by the ambivalence of the body-soul relationship. The person who is most successful in triggering laughter is the comic; most philosophers describe him also as the appearance of contradiction and incongruity. In the history of theology laughter has often been criticized or even forbidden. In the Middle Ages, however, there was a culture of the jester and even a theological esteem of laughter. Could not the Christian’s laughter be understood as the expression of his contradictory existence of being sinner and justified? Placed « outside himself » as a sinner who has been pardoned, the Christian is henceforth able to laugh. (shrink)

This is a sequel to Augustine Shutte's previous book Philosophy for Africa. In that book he engages with some concepts central to traditional African thinking about human nature and society. In this book he offers a new interpretation of the chief ethical idea in African thought, Ubuntu. He argues that it complements the central European ethical notion of individual freedom, and shows how the two ideas can be combined to form an ethic based on a richer understanding of our humanity. (...) He then applies this ethic to different spheres of life: gender relations, sex and family life, education, health care, work, politics and religion. In each sphere he tries to show how an ethic of Ubuntu can provide concrete guidance for our continuing struggle to make a multi-cultural South Africa a truly humane society. (shrink)

_A fresh, new translation of Augustine’s inaugural work as a Christian convert_ The first four works written by St. Augustine of Hippo after his conversion to Christianity are dialogues that have influenced prominent thinkers from Boethius to Bernard Lonergan. Usually called the Cassiciacum dialogues, these four works are a “literary triumph,” combining Ciceronian and neo-Platonic philosophy, Roman comedy and Vergilian poetry, and early Christian theology. They are also, arguably, Augustine’s most charming works, exhibiting his whimsical levity and ironic wryness. In (...) this second, brief dialogue, Augustine and his mother, brother, son, and friends celebrate his thirty-second birthday by having a “feast of words” on the nature of happiness that includes a bittersweet metaphorical birthday cake. Using a process of reasoning that is philosophical as well as theological, Augustine and the group conclude that the truly happy life consists of “having God” through faith, hope, and charity. Michael Foley’s clear, precise and playful translations are accompanied by his brief, illuminating commentaries. (shrink)

In this new translation the brilliant and impassioned descriptions of Augustine's colourful early life are conveyed to the English reader with accuracy and art. Augustine tells of his wrestlings to master his sexual drive, his rare ascent from a humble Algerian farm to the edge of the corridors of high power at the imperial court of Milan, and his renunciation of secular ambition and marriage as he recovered the faith that his mother had taught him. It was in a Milan (...) garden that Augustine finally achieved the act of will to Christian conversion, which he compared to a lazy man in bed finally deciding it is time to get up and face the day. ABOUT THE SERIES: For over 100 years Oxford World's Classics has made available the widest range of literature from around the globe. Each affordable volume reflects Oxford's commitment to scholarship, providing the most accurate text plus a wealth of other valuable features, including expert introductions by leading authorities, helpful notes to clarify the text, up-to-date bibliographies for further study, and much more. (shrink)

The violation of Bell inequalities seems to establish an important fact about the world: that it is non-local. However, this result relies on the assumption of the statistical independence of the measurement settings with respect to potential past events that might have determined them. Superdeterminism refers to the view that a local, and determinist, account of Bell inequalities violations is possible, by rejecting this assumption of statistical independence. We examine and clarify various problems with superdeterminism, looking in particular at its (...) consequences on the nature of scientific laws and scientific reasoning. We argue that the view requires a neo-Humean account of at least some laws, and creates a significant problem for the use of statistical independence in other parts of physics and science more generally. (shrink)

We approach the physics of \emph{minimal coupling} in general relativity, demonstrating that in certain circumstances this leads to violations of the \emph{strong equivalence principle}, which states that, in general relativity, the dynamical laws of special relativity can be recovered at a point. We then assess the consequences of this result for the \emph{dynamical perspective on relativity}, finding that potential difficulties presented by such apparent violations of the strong equivalence principle can be overcome. Next, we draw upon our discussion of the (...) dynamical perspective in order to make explicit two `miracles' in the foundations of relativity theory. We close by arguing that the above results afford us insights into the nature of special relativity, and its relation to general relativity. (shrink)