The paper shows how the Bohmian approach to quantum physics can be applied to develop a clear and coherent ontology of non-perturbative quantum gravity. We suggest retaining discrete objects as the primitive ontology also when it comes to a quantum theory of space-time and therefore focus on loop quantum gravity. We conceive atoms of space, represented in terms of nodes linked by edges in a graph, as the primitive ontology of the theory and show how a non-local law in which (...) a universal and stationary wave-function figures can provide an order of configurations of such atoms of space such that the classical space-time of general relativity is approximated. Although there is as yet no fully worked out physical theory of quantum gravity, we regard the Bohmian approach as setting up a standard that proposals for a serious ontology in this field should meet and as opening up a route for fruitful physical and mathematical investigations. (shrink)

We present a new metaphysical framework for physics that is conceptually clear, ontologically parsimonious, and empirically adequate. This framework relies on the notion of self-subsisting structure, that is, a set of fundamental physical elements whose individuation and behavior are described in purely relational terms, without any need for a background spacetime. Although the specification of the fundamental elements of the ontology depends on the particular physical domain considered---and is thus susceptible to scientific progress---, the empirically successful structural features of the (...) framework are preserved through theory change. The kinematics and dynamics of these self-subsisting structures are technically implemented using the theoretical framework of Pure Shape Dynamics, which provides a completely relational physical description of a system in terms of the intrinsic geometry of a suitably defined space called shape space. (shrink)

An ontology of Leibnizian relationalism, consisting in distance relations among sparse matter points and their change only, is well recognized as a serious option in the context of classical mechanics. In this paper, we investigate how this ontology fares when it comes to general relativistic physics. Using a Humean strategy, we regard the gravitational field as a means to represent the overall change in the distance relations among point particles in a way that achieves the best combination of being simple (...) and being informative. (shrink)

The paper discusses from a metaphysical standpoint the nature of the dependence relation underpinning the talk of mutual action between material and spatiotemporal structures in general relativity. It is shown that the standard analyses of dependence in terms of causation or grounding are ill-suited for the general relativistic context. Instead, a non-standard analytical framework in terms of structural equation modeling is exploited, which leads to the conclusion that the kind of dependence encoded in the Einstein field equations is a novel (...) one. (shrink)

This paper elaborates on relationalism about space and time as motivated by a minimalist ontology of the physical world: there are only matter points that are individuated by the distance relations among them, with these relations changing. We assess two strategies to combine this ontology with physics, using classical mechanics as example: the Humean strategy adopts the standard, non-relationalist physical theories as they stand and interprets their formal apparatus as the means of bookkeeping of the change of the distance relations (...) instead of committing us to additional elements of the ontology. The alternative theory strategy seeks to combine the relationalist ontology with a relationalist physical theory that reproduces the predictions of the standard theory in the domain where these are empirically tested. We show that, as things stand, this strategy cannot be accomplished without compromising a minimalist relationalist ontology. (shrink)

An important part of the influential Humean doctrine in philosophy is the supervenience principle (sometimes referred to as the principle of separability). This principle asserts that the complete state of the world supervenes on the intrinsic properties of its most fundamental components and their spatiotemporal relations (the so-called Humean mosaic). There are well-known arguments in the literature purporting to show that in quantum mechanics the Humean supervenience principle is violated, due to the existence of entangled states. Recently, however, arguments have (...) been presented to the effect that the supervenience principle can be defended in Bohmian mechanics. The key element of this strategy lies in the observation that according to Bohmian mechanics the fundamental facts about particles are facts about their spatial locations, and moreover, for any proper subsystem of the world its state may non-trivially depend on the spatial configuration of the rest of the universe. Thus quantum-mechanical states of subsystems do not represent their intrinsic properties but rather characterize their relations with the environment. In this paper we point out the worry that this Bohmian strategy --known as Bohumianism-- saves the letter but not the spirit of the Humean doctrine of supervenience, since it prima facie violates another seemingly important Humean principle, which we call Strong Supervenience and whose denial implies the existence of necessary connections among distinct individuals. We argue that the best defense for Bohumians is to question the fundamental existence of complex physical systems and their states by treating any reference to them as a convenient description of the underlying collection of Bohmian particles. We consider several pros and cons of this strategy. (shrink)

The goal of this essay is twofold. First, it provides a quick look at the foundations of modern relational mechanics by tracing its development from Julian Barbour and Bruno Bertotti's original ideas until present-day's pure shape dynamics. Secondly, it discusses the most appropriate metaphysics for pure shape dynamics, showing that relationalism is more of a nuanced thesis rather than an elusive one. The chapter ends with a brief assessment of the prospects of pure shape dynamics in light of quantum physics.

Elise Crull claims that by invoking decoherence it is possible to obviate many “fine grained” issues often conflated under the common designation of measurement problem, and to make substantial progresses in the fields of quantum gravity and quantum cosmology, without any early incorporation of a particular interpretation in the quantum formalism. We point out that Crull is mistaken about decoherence and tacitly assumes some kind of interpretation of the quantum formalism.

Quantum gravity is supposed to be the most fundamental theory, including a quantum theory of the metrical field (spacetime). However, it is not clear how a quantum theory of gravity could account for classical phenomena, including notably measurement outcomes. But all the evidence that we have for a physical theory is based on measurement outcomes. We consider this problem in the framework of canonical quantum gravity, pointing out a dilemma: all the available accounts that admit classical phenomena presuppose entities with (...) a well-defined spatio-temporal localization (“local beables” in John Bell's terms) as primitive. But there seems to be no possibility to include such primitives in canonical quantum gravity. However, if one does not do so, it is not clear how entities that are supposed to be ontologically prior to spacetime could give rise to entities that then are spatio-temporally localized. (shrink)

The paper presents an inquiry into the question regarding the compatibility of Bohmian mechanics, intended as a non-local theory of moving point-like particles, with background independence. This issue is worth being investigated because, if the Bohmian framework has to be of some help in developing new physics, it has to be compatible with the most well-established traits of modern physics, background independence being one of such traits. The paper highlights the fact that the notion of background independence in the context (...) of spacetime physics is slippery and interpretation-laden. It is then suggested that the best-matching framework developed by Julian Barbour might provide a robust enough meaning of background independence. The structure of Bohmian dynamics is evaluated against this framework, reaching some intermediate results that speak in favor of the fact that Bohmian mechanics can be made background independent. (shrink)

The paper presents a program to construct a non-relativistic relational Bohmian theory, that is, a theory of N moving point-like particles that dispenses with space and time as fundamental background structures. The relational program proposed is based on the best-matching framework originally developed by Julian Barbour. In particular, the paper focuses on the conceptual problems that arise when trying to implement such a program. It is argued that pursuing a relational strategy in the Bohmian context leads to a more parsimonious (...) ontology than that of standard Bohmian mechanics without betraying the original motivations for adopting a primitive ontology approach to quantum physics. It is also shown how a relational Bohmian approach might clarify the issue of the timelessness of the dynamics resulting from the quantization of a classical relational system of particles. (shrink)

Pure shape dynamics (PSD) is a novel implementation of the relational framework originally proposed by Julian Barbour and Bruno Bertotti. PSD represents a Leibnizian/Machian approach to physics in that it completely describes the dynamical evolution of a physical system without resorting to any structure external to the system itself. The chapter discusses how PSD effectively describes a de Broglie-Bohm N-body system and the conceptual benefits of such a relational description. The analysis will highlight the new directions in the quest for (...) an understanding of the nature of the wave function that are opened up by a modern relationalist elaboration on de Broglie's and Bohm's original insights. (shrink)

The paper investigates the kind of dependence relation that best portrays Machian frame-dragging in general relativity. The question is tricky because frame-dragging relates local inertial frames to distant distributions of matter in a time-independent way, thus establishing some sort of non-local link between the two. For this reason, a plain causal interpretation of frame-dragging faces huge challenges. The paper will shed light on the issue by using a generalized structural equation model analysis in terms of manipulationist counterfactuals recently applied in (...) the context of metaphysical enquiry by Schaffer (2016) and Wilson (2017). The verdict of the analysis will be that frame-dragging is best understood in terms of a novel type of dependence relation that is half-way between causation and grounding. (shrink)

The paper investigates the type of realism that best suits the framework of decoherence taken at face value without postulating a plurality of worlds, or additional hidden variables, or non-unitary dynamical mechanisms. It is argued that this reading of decoherence leads to an extremely radical type of perspectival realism, especially when cosmological decoherence is considered.

The paper presents a metaphysical characterization of spatiotemporal backgrounds from a realist perspective. The conceptual analysis is based on a heuristic sketch that encompasses the common formal traits of the major spacetime theories, such as Newtonian mechanics and general relativity. It is shown how this framework can be interpreted in a fully realist fashion, and what is the role of background structures in such a picture. In the end it is argued that, although backgrounds are a source of metaphysical discomfort, (...) still they make a spacetime theory easy to interpret. It is also suggested that this conclusion partially explains why the notion of background independence carries a lot of conceptual difficulties. (shrink)

The dynamics of general relativity is encoded in a set of ten differential equations, the so-called Einstein field equations. It is usually believed that Einstein's equations represent a physical law describing the coupling of spacetime with material fields. However, just six of these equations actually describe the coupling mechanism: the remaining four represent a set of differential relations known as Bianchi identities. The paper discusses the physical role that the Bianchi identities play in general relativity, and investigates whether these identities (...) --qua part of a physical law-- highlight some kind of a posteriori necessity in a Kripkean sense. The inquiry shows that general relativistic physics has an interesting bearing on the debate about the metaphysics of the laws of nature. (shrink)

The paper considers the "GR-desideratum", that is, the way general relativity implements general covariance, diffeomorphism invariance, and background independence. Two cases are discussed where 5-dimensional generalizations of general relativity run into interpretational troubles when the GR-desideratum is forced upon them. It is shown how the conceptual problems dissolve when such a desideratum is relaxed. In the end, it is suggested that a similar strategy might mitigate some major issues such as the problem of time or the embedding of quantum non-locality (...) into relativistic spacetimes. (shrink)

This book provides an up-to-date overview of the foundations of spacetime physics. It features original essays written by world-class experts in the physics and philosophy of spacetime. The foundational questions regarding the origin and nature of spacetime are branching into new and exciting directions. These questions are not restricted to the quantum gravity program but also arise in the context of a well-established theory like general relativity. Against the background of these quick and diverse developments, this volume features a broad (...) range of perspectives on spacetime. Part I focuses on the nature of spacetime in non-quantum theories, such as Newtonian mechanics and relativity. Part II explores some intriguing conceptual implications of developing a quantum theory of spacetime. The Foundations of Spacetime Physics is an essential resource for scholars and advanced students working in philosophy of physics, philosophy of science, and scientific metaphysics. (shrink)

Two recent papers appeared in FOOP disagree regarding the role played by decoherence in quantum physics. On the one hand, Elise Crull considers that decoherence, by itself, solves many conceptual problems in quantum physics, with no need of interpretative considerations. On the other hand, Antonio Vassallo and Michael Esfeld reply by correctly claiming that, although decoherence is a powerful tool to deal with conceptual problems, it does not dispense us from interpreting the formalism. In this brief note we (...) want to contribute to the debate with further considerations from another viewpoint. In this work we show that the discussions "decoherence versus interpretation" revolve around whether the theory of decoherence requires interpretive considerations to solve the measurement problem. In general, those discussions take the theory of decoherence for granted, as if it would not involve any difficulty. Therefore, they commonly focus on the "interpretation" wing: even in the case that the open system decoheres in a given basis, the whole closed system is still in a superposition and, thus, without an adequate interpretation, it cannot be said that the observables defined by that basis behave classically. Here we have focused on the "decoherence" wing: given the conceptual challenges that the theory must face and the alternative approaches to the orthodox view, the understanding of the very phenomenon of decoherence still requires a great deal of interpretive work. (shrink)

SummaryIn his Origins of Analytical Philosophy Michael Dummett claims that even in this earliest writings Frege can be identified as the grandfather of analytical philosophy. My aim here is to show how difficult it is to make out this claim convincingly.

This paper discusses George Boole’s two distinct approaches to the explanatory relationship between logical and psychological theory. It is argued that, whereas in his first book he attributes a substantive role to psychology in the foundation of logical theory, in his second work he abandons that position in favour of a linguistically conceived foundation. The early Boole espoused a type of psychologism and later came to adopt a type of anti-psychologism. To appreciate this invites a far-reaching reassessment of his philosophy (...) of logic. (shrink)

Damage repair is a fundamental requirement of all life as organisms find themselves in challenging and fluctuating environments. In particular, damage to the barrier between an organism and its environment (e.g. skin, plasma membrane, bacterial cell envelope) is frequent because these organs/organelles directly interact with the external world. Here, we discuss the general strategies that bacteria use to cope with damage to their cell envelope and their repair limits. We then describe a novel damage‐coping mechanism used by multicellular myxobacteria. We (...) propose that cell‐cell transfer of membrane material within a population serves as a wound‐healing strategy and provide evidence for its utility. We suggest that – similar to how tissues in eukaryotes have evolved cooperative methods of damage repair – so too have some bacteria that live a multicellular lifestyle. (shrink)

Visual shape discrimination is faster for objects close to the body, in the peripersonal space (PPS), compared to objects far from the body. Visual processing enhancement in PPS occurs also when perceived depth is based on 2D pictorial cues. This advantage has been observed from relatively low-level (detection, size, orientation) to high-level visual features (face processing). While multisensory association also displays proximal advantages, whether PPS influences visual perceptual learning remains unclear. Here, we investigated whether perceptual learning effects vary according to (...) the distance of visual stimuli (near or far) from the observer, illusorily induced by leveraging the Ponzo illusion. Participants performed a visual search task in which they reported whether a specific target object orientation (e.g., triangle pointing downward) was present among distractors. Performance was assessed before and after practising the visual search task (30 minutes/day for 5 days) at either the close (near group) or far (far group) distance. Results showed that participants that performed the training in the near space did not improve. By contrast, participants that performed the training in the far space showed an improvement in the visual search task in both the far and near spaces. We suggest that such improvement following the far training is due to a greater deployment of attention in the far space, which could make the learning more effective and generalize across spaces. (shrink)

Visual objects in the peripersonal space (PPS), are perceived faster than farther ones, appearing in the extrapersonal space (EPS). This shows preferential processing for visual stimuli near our body. Such an advantage should favor visual perceptual learning occurring near, as compared to far from observers, but opposite evidence has been recently provided from online testing protocols, showing larger perceptual learning in the far space. Here, we ran two laboratory-based experiments investigating whether visual training in PPS and EPS has different effects. (...) We used the horizontal Ponzo Illusion to create a lateralized depth perspective while participants completed a visual search task in which they reported whether or not a specific target object orientation (e.g., a triangle pointing upward) was present amongst distractors. This task was completed before and after a training phase in either the (illusory) near or far space for one hour. In Experiment 1, the near space was in the left hemispace, whereas in Experiment 2 it was in the right. Results showed that, in both experiments, participants were more accurate after training in the far space, whereas training in the near space led to either improvement in the far space (Exp. 1), or no change (Exp. 2). Moreover, we found a larger visual perceptual learning when stimuli were presented in the left compared to the right hemispace. Differently from visual processing, visual perceptual learning is more effective in the far space. We propose that depth is a key dimension that can be used to improve human visual learning. (shrink)

Il volume fornisce una nuova traduzione italiana, con introduzione storico-filosofica e commento del trattato plotiniano Sulla bellezza intelligibile (Enn. V 8 [31]). In Enn. V 8 [31] Plotino cerca di indagare il complesso rapporto tra il carattere “ideale” e quello “reale” della bellezza e delle sue diverse forme di manifestazione nel mondo. Tra queste, che la tradizione precedente aveva recluso negli spazi angusti dell’arte imitativa, il filosofo neoplatonico prende spunto dall’opera dello scultore, per poi ampliare lo sguardo verso altri aspetti (...) della bellezza: in particolare, quello del suo essere (ontologia) e quello del suo valore (etica). Lungi dall’essere una semplice testimonianza della corrente mistica del pensiero antico, il trattato Sulla bellezza intelligibile è anche (forse soprattutto) un invito all’azione e un comando a rendere oggetto del proprio agire innanzitutto sé stessi. Come Fidia dimostrò, grazie al suo Zeus Olimpio, che un grande artista non può limitarsi a concepire l’ideale, ma deve anche realizzarlo concretamente nella realtà; così ogni uomo, se vero uomo, sa ergersi sulla materia che lo circonda e farsi tempio della Luce intelligibile. *** Der vorliegende Band bietet eine neue italienische Übersetzung samt einer philosophiegeschichtlichen Einleitung und Kommentar zur Abhandlung Plotins Über die intelligible Schönheit (Enn. V 8 [31]). In Enn. V 8 [31] untersucht Plotin die komplizierte Beziehung zwischen dem ‚ideellen‘ und dem ‚realistischen‘ Charakter der Schönheit und ihren verschiedenen Erscheinungsformen in der Welt, die von der früheren Tradition als künstliche Nachahmungen kritisiert wurden. Als Beispiel zieht der neuplatonische Philosoph das Werk des Bildhauers heran und erweitert daraufhin seine Untersuchung im Hinblick auf andere Aspekte der Schönheit, insbesondere ihr ‚Sein‘ (Ontologie) und ihren ‚Wert‘ (Ethik). Weit davon entfernt ein Beweis für den mystischen Teil des antiken Denkens zu sein, ist die Abhandlung Über die intelligible Schönheit auch im Besonderen ein Aufruf zum Handeln und ein Befehl an jeden Menschen, sich selbst zum Objekt seines Handelns zu machen. Wie Phidias anhand seines Zeus bewies, ist es für einen großen Künstler nicht möglich, nur das Ideale zu denken, er muss es auch in der Realität verwirklichen. Auf dieselbe Art und Weise muss jeder (wahre) Mensch über der Materie stehen und sich selbst zum Tempel des intelligiblen Lichtes erheben, das überall sein Leben beleuchtet. (shrink)

Inhaltsverzeichnis/Table of Contents:IntroductionAntónio ZILHÃO: Folk-Psychology, Rationality and Human ActionJoão BRANQUINHO: The Problem of Cognitive DynamicsJ.P. MONTEIRO: Hume, Induction and Single ExperimentsMarco RUFFINO: The Primacy of Concepts and the Priority of Judgments in Frege's LogicJoão Vergílio Gallerani CUTER: Die unanwendbare Arithmetik des TractatusSílvio PINTO: Wittgenstein's Anti-PlatonismFernando FERREIRA: A Substitutional Framework for Arithmetical ValidityJ.R. CROCA & R.N. MOREIRA: Indeterminism Versus CausalismLuíz MONIZ PEREIRA: The Logical Impingement of Artifical Intelligence.

INCONTINENCE, HONOURING SUNK COSTS AND RATIONALITY According to a basic principle of rationality, the decision to engage in a course of action should be determined solely by the analysis of its consequences. Thus, considerations associated with previous use of resources should have no bearing on an agent’s decision-making process. Frequently, however, agents persist carrying on an activity they themselves judge to be nonoptimal under the circumstances because they have already allocated resources to that activity. When this is the case, agents (...) are said to be honouring sunk costs. Honouring sunk costs is thus typically viewed as irrational economic behaviour. Two striking findings of the psychological literature on the sunk cost effect are that it is, in general, not lessened by having taken previously courses in economics, and that agents who did take such courses and that do honour sunk costs seem to be frequently aware of a cognitive dissonance in their behaviour. Davidson’s account of the possibility conditions of incontinent action renders continent action materially unfeasible. The very idea of incontinent action becomes thus a hollow one. I’ll present an alternative description of these possibility conditions that renders continent action materially feasible, and both, continent and incontinent action, cognitively plausible. In a nutshell, my proposal rests upon the drawing of an essential cognitive contrast between explicit processes of deliberative reasoning and lower level heuristic procedures. I conclude the paper arguing that my redescription of incontinent action accounts for the above mentioned cognitive dissonance effect better than the alternatives and that viewing at least an important subset of behaviours of honouring sunk costs as incontinent actions will enable us to consider them as peculiar manifestations of a more general and meaningful pattern in human behaviour. (shrink)

Pieranna Garavaso and Nicla Vassallo investigate Gottlob Frege's largely unexplored notion of thinking to provide insight into the roles of language in expressing thoughts and in fostering the development of human knowledge. The analysis will benefit studies of epistemology, logic, philosophy of mind, psychology, and philosophy of language.

The essays in this collection, which derive from the conference 'Alienation and Alterity: Otherness in Modern and Contemporary Francophone Contexts', held at the University of Exeter in September 2007, explore various aspects of this ...

Historically, George Boole’s philosophy of logic has been regarded as the very opposite of Gottlob Frege’s, insofar as Frege is characterized as a strong logical anti-psychologist. Although there are significant differences between Frege’s and Boole’s views on logic, there are also significant similarities, which provide support for our representation of Frege’s philosophy of logic as weakly psychologistic. Both Boole and Frege aspire to capture the essence of a pure and ideally perfect language that may faithfully express correct reasoning, but Boole’s (...) trust in the power of natural language is stronger than Frege’s. Although we cannot adequately defend this claim, we submit that a thorough examination of the differences between Frege’s and Boole’s views on symbolic and natural languages may lead to a more interesting comparison of their stances on logic and thinking than the often repeated contrast in their attitudes toward psychologism. (shrink)

Cet article réexamine la totalité des témoignages sur la pensée démocritéenne de l’origine du culte divin. Une étude approfondie de ces témoignages nous autorise à affirmer que, dans l’esprit de Démocrite, le culte des dieux ne dérivait pas seulement d’une peur des phénomènes naturels hostiles, mais aussi de la reconnaissance pour les événements favorables à la survie des humains. Il est à présent possible de réinterpréter cette conception selon un point de vue polémique : Démocrite n’aurait pas nié l’existence des (...) dieux, mais plutôt exposé les mécanismes psychologiques qui conduisent les hommes ordinaires à croire dans les dieux traditionnels. Contre la croyance superstitieuse, il démontre, en s’aidant également de la théorie des εἴδωλα, que les seuls dieux qui existent sont pourvus de la même « raison » que celle à l’œuvre dans la nature et grâce à laquelle les hommes peuvent comprendre ses phénomènes aussi suprenants que variés. (shrink)

The dual purpose of this paper is to examine whether the epistemology of testimony is useful in clarifying reflections on the Holocaust, and on the hand to employ the Holocaust as a test case for the epistemology of testimony in itself. In contrast to any form of epistemological individualism, I examine the epistemological problems and conditions that face both an historian (an indirect witness) and an ocular witness (a direct one). In this discussion, I will not be able to give (...) precise answers to various questions, in particular concerning the relationship between these types of witnesses. I will conclude that although testimony requires truth of the proposition testified, lying seems better that telling the truth in cases where it is instrumental in saving many human life from the brutality of the Nazis. This conclusion is modest: while the epistemology of testimony can perhaps be of help in reflecting upon the Holocaust, it surely brings up more problems than what it can solve. Notwithstanding, I do not believe that the fault is with the epistemology of testimony, but rather that because of its extreme cruelty, inhumanity, and horror, it is too complex to say when a serious testimony about Holocaust is fully justified. (shrink)

In Folder n. 7, Container 49 of the Vlastos-Nachlass, an as-yet unpublished series of notes by Gregory Vlastos on Alcmaeon and his empirical method are preserved across two fascicles. After briefly contextualizing Vlastos' remarks within the history of scholarship on Alcmaeon, this paper provides the first annotated reconstruction of the manuscript's extant portion.

Caro leitor! Em busca de sempre mais apresentar reflexões consistentes e relevantes para o pensar teológico, em conexão com o mundo e às urgências da Igreja, a presente edição trás importantes temas que ajudam refletir a realidade humana à luz do mistério de Deus. Por isso, os artigos oferecidos nas mais variadas áreas, a saber: bíblico-teológica, dogmática, moral, pastoral, antropologia teológica, filosofia e eclesiologia, dão suporte científico e metodológico para a reflexão teológica. Antes de conferir as novidades desta edição, gostaria (...) de comunicar que esta Revista Eletrônica conquistou um espaço ainda maior de publicação, ao tornar-se indexada na base de dados do Directory of Open Access Journals (DOAJ). (shrink)