In this paper, I discuss one form of the idea that spacetime and gravity might ‘emerge’ from quantum theory, i.e. via a holographic duality, and in particular via AdS/CFT duality. I begin by giving a survey of the general notion of duality, as well as its connection to emergence. I then review the AdS/CFT duality and proceed to discuss emergence in this context. We will see that it is difficult to find compelling arguments for the emergence of full quantum gravity (...) from gauge theory via AdS/CFT, i.e. for the boundary theory's being metaphysically more fundamental than the bulk theory. (shrink)

This article investigates and resolves the question whether gauge symmetry can display analogs of the famous Galileo’s ship scenario. In doing so, it builds on and clarifies the work of Greaves and Wallace on this subject.

As a prolegomenon to understanding the sense in which dualities are theoretical equivalences, we investigate the intuitive `equivalence' of hyper-regular Lagrangian and Hamiltonian classical mechanics. We show that the symplectification of these theories provides a sense in which they are isomorphic, and mutually and canonically definable through an analog of `common definitional extension'.

This article uncovers a foundational relationship between the ‘gauge symmetry’ of a Newton-Cartan theory and the celebrated Trautman Recovery Theorem and explores its implications for recent philosophical work on Newton-Cartan gravitation.

Philosophers of physics and physicists have long been intrigued by the analogies and disanalogies between gravitational theories and gauge theories. Indeed, repeated attempts to collapse these disanalogies have made us acutely aware that there are fairly general obstacles to doing so. Nonetheless, there is a special case space-time dimensions) in which gravity is often claimed to be identical to a gauge theory. I subject this claim to philosophical scrutiny in this article. In particular, I analyse how the standard disanalogies can (...) be overcome in dimensions, and consider whether really licenses the interpretation of gravity as a gauge theory. Our conceptual analysis reveals more subtle disanalogies between gravity and gauge, and connects these to interpretive issues in classical and quantum gravity. 1 Introduction1.1 Motivation1.2 Prospectus2 Disanalogies3 Three-dimensional gravity and gauge3.1 gravity3.2 Chern–Simons3.2.1 Cartan geometry3.2.2 Overcoming obst-gauge via Cartan connections3.3 Disanalogies collapsed4 Two More Disanalogies4.1 What about the symmetries?4.2 The phase spaces of the two theories5 Summary and Conclusion. (shrink)

Rovelli’s “Why Gauge?” offers a parable to show that gauge-dependent quantities have a modal and relational physical significance. We subject the morals of this parable to philosophical scrutiny and argue that, while Rovelli’s main point stands, there are important disanalogies between his parable and Yang-Mills type gauge theory.

We discuss some aspects of the relation between dualities and gauge symmetries. Both of these ideas are of course multi-faceted, and we confine ourselves to making two points. Both points are about dualities in string theory, and both have the ‘flavour’ that two dual theories are ‘closer in content’ than you might think. For both points, we adopt a simple conception of a duality as an ‘isomorphism’ between theories: more precisely, as appropriate bijections between the two theories’ sets of states (...) and sets of quantities. The first point is that this conception of duality meshes with two dual theories being ‘gauge related’ in the general philosophical sense of being physically equivalent. For a string duality, such as T-duality and gauge/gravity duality, this means taking such features as the radius of a compact dimension, and the dimensionality of spacetime, to be ‘gauge’. The second point is much more specific. We give a result about gauge/gravity duality that shows its relation to gauge symmetries to be subtler than you might expect. For gauge theories, you might expect that the duality bijections relate only gauge-invariant quantities and states, in the sense that gauge symmetries in one theory will be unrelated to any symmetries in the other theory. This may be so in general; and indeed, it is suggested by discussions of Polchinski and Horowitz. But we show that in gauge/gravity duality, each of a certain class of gauge symmetries in the gravity/bulk theory, viz. diffeomorphisms, is related by the duality to a position-dependent symmetry of the gauge/boundary theory. (shrink)

Rovelli's "Why Gauge?" offers a parable to show that gauge-dependent quantities have a modal and relational physical significance. We subject the morals of this parable to philosophical scrutiny and argue that, while his overarching point stands, there are subtle disanalogies between his parable and our best gauge theories, e.g. Yang-Mills theory and General Relativity.

The idea that gauge theory has `surplus' structure poses a puzzle: in one much discussed sense, this structure is redundant; but on the other hand, it is also widely held to play an essential role in the theory. In this paper, we employ category-theoretic tools to illuminate an aspect of this puzzle. We precisify what is meant by `surplus' structure by means of functorial comparisons with equivalence classes of gauge fields, and then show that such structure is essential for any (...) theory that represents a rich collection of physically relevant fields which are `local' in nature. (shrink)

It is part of information theory folklore that, while quantum theory prohibits the generic cloning of states, such cloning is allowed by classical information theory. Indeed, many take the phenomenon of no-cloning to be one of the features that distinguishes quantum mechanics from classical mechanics. In this paper, we use symplectic geometry to argue that pace conventional wisdom, in the case where one does not include a machine system, there is an analog of the no-cloning theorem for classical systems. However, (...) upon adjoining a non-trivial machine system one finds that, pace the quantum case, the obstruction to cloning disappears for pure states. We then discuss the difference between this result and the quantum case, and show that it can be explained in terms of the rigidity of the theories' respective geometries. Finally, we discuss the relationship between this result and classical no-cloning arguments in the context of symmetric monoidal categories and statistical classical mechanics. (shrink)

Foundations of Relational Realism: A Topological Approach to Quantum Mechanics and the Philosophy of Nature by Michael Epperson and Elias Zafiris sets out to achieve three goals: to develop a version of Whiteheadian metaphysics that the authors call “relational realism”; to formalize relational realism in terms of category theory, in particular sheaf theory; and to use relational realism to solve the interpretative problems of quantum mechanics. These goals are ambitious, to say the least, and all this is leaving aside those (...) sections of FRR which argue that relational realism yields the key to understanding quantum gravity!The text is 388 pages long and comprises two parts. Part I, by Epperson, introduces relational realism and its application to quantum mechanics. Part II, by Zafiris, develops the sheaf theory formalism for relational realism. As the authors say, their exposition is “nonlinear”, and this feature of FRR, alon .. (shrink)

Category theory has become central to certain aspects of theoretical physics. Bain has recently argued that this has significance for ontic structural realism. We argue against this claim. In so doing, we uncover two pervasive forms of category-theoretic generalization. We call these ‘generalization by duality’ and ‘generalization by categorifying physical processes’. We describe in detail how these arise, and explain their significance using detailed examples. We show that their significance is two-fold: the articulation of high-level physical concepts, and the generation (...) of new models. 1 Introduction2 Categories and Structuralism 2.1 Categories: abstract and concrete 2.2 Structuralism: simple and ontic3 Bain’s Two Strategies 3.1 A first strategy for defending Objectless 3.2 A second strategy for defending Objectless4 Two Forms of Categorical Generalization 4.1 Generalization by duality 4.2 Generalization by categorification 4.3 The role of category theory in physics5 Conclusion. (shrink)

We make two points about dualities in string theory. The first point is that the conception of duality, which we will discuss, meshes with two dual theories being ‘gauge related’ in the general philosophical sense of being physically equivalent. The second point is a result about gauge/gravity duality that shows its relation to gauge symmetries to be subtler than one might expect: each of a certain class of gauge symmetries in the gravity theory, that is, diffeomorphisms, is related to a (...) position-dependent symmetry of the gauge theory. (shrink)

We construct a notion of teleparallelization for Newton-Cartan theory, and show that the teleparallel equivalent of this theory is Newtonian gravity; furthermore, we show that this result is consistent with teleparallelization in general relativity, and can be obtained by null-reducing the teleparallel equivalent of a five-dimensional gravitational wave solution. This work thus strengthens substantially the connections between four theories: Newton-Cartan theory, Newtonian gravitation theory, general relativity, and teleparallel gravity.

The equivalence principle has constituted one of the cornerstones of discussions in the foundations of spacetime theories over the past century. However, up to this point the principle has been considered overwhelmingly only within the context of relativistic physics. In this article, we demonstrate that the principle has much broader, super-theoretic significance: to do so, we present a unified framework for understanding the principle in its various guises, applicable to both relativistic and Newtonian contexts. We thereby deepen significantly our understanding (...) of the role played by the equivalence principle in a broad class of spacetime theories. (shrink)

Recently, there has been some discussion of how Dutch Book arguments might be used to demonstrate the rational incoherence of certain hidden variable models of quantum theory. In this paper, we argue that the 'form of inconsistency' underlying this alleged irrationality is deeply and comprehensively related to the more familiar 'inconsistency' phenomenon of contextuality. Our main result is that the hierarchy of contextuality due to Abramsky and Brandenburger corresponds to a hierarchy of additivity/convexity-violations which yields formal Dutch Books of different (...) strengths. We then use this result to provide a partial assessment of whether these formal Dutch Books can be interpreted normatively. (shrink)

The recent debate about whether gauge symmetries can be empirically significant has focused on the possibility of 'Galileo's ship' types of scenarios, where the symmetries effect relational differences between a subsystem and the environment. However, it has gone largely unremarked that apart from such Galileo's ship scenarios, Greaves and Wallace (2014) proposed that gauge transformations can also be empirically significant in a 'non-relational' manner that is analogous to a Faraday-cage scenario, where the subsystem symmetry is related to a change in (...) a charged boundary state. In this paper, we investigate the question of whether such non-relational scenarios are possible for gauge theories. Remarkably, the answer to this question turns out to be closely related to a foundational puzzle that has driven a host of recent developments at the frontiers of theoretical physics. By drawing on these recent developments, we show that a very natural way of elaborating on Greaves and Wallace's claim of non-relational empirical significance for gauge symmetry is incoherent. However, we also argue that much of what they suggest is correct in spirit: one can indeed construct non-relational models of the kind they sketch, albeit ones where the empirical significance is not witnessed by a gauge symmetry but instead by a superficially similar boundary symmetry. Furthermore, the latter casts doubt on whether one really abandons Galileo's ship in such scenarios. (shrink)

The last two decades have seen two significant trends emerging within the philosophy of science: the rapid development and focus on the philosophy of the specialised sciences, and a resurgence of Aristotelian metaphysics, much of which is concerned with the possibility of emergence, as well as the ontological status and indispensability of dispositions and powers in science. Despite these recent trends, few Aristotelian metaphysicians have engaged directly with the philosophy of the specialised sciences. Additionally, the relationship between fundamental Aristotelian concepts—such (...) as "hylomorphism", "substance", and "faculties"—and contemporary science has yet to receive a critical and systematic treatment. _Neo-Aristotelian Perspectives on Contemporary Science _aims to fill this gap in the literature by bringing together essays on the relationship between Aristotelianism and science that cut across interdisciplinary boundaries. The chapters in this volume are divided into two main sections covering the philosophy of physics and the philosophy of the life sciences. Featuring original contributions from distinguished and early-career scholars, this book will be of interest to specialists in analytical metaphysics and the philosophy of science. (shrink)

It is now well-known that Newton–Cartan theory is the correct geometrical setting for modelling the quantum Hall effect. In addition, in recent years edge modes for the Newton–Cartan quantum Hall effect have been derived. However, the existence of these edge modes has, as of yet, been derived using only orthodox methodologies involving the breaking of gauge-invariance; it would be preferable to derive the existence of such edge modes in a gauge-invariant manner. In this article, we employ recent work by Donnelly (...) and Freidel in order to accomplish exactly this task. Our results agree with known physics, but afford greater conceptual insight into the existence of these edge modes: in particular, they connect them to subtle aspects of Newton–Cartan geometry and pave the way for further applications of Newton–Cartan theory in condensed matter physics. (shrink)

This paper is an essay in counterfactual epistemology. What if experience have high-level contents, to the effect that something is a lemon or that someone is sad? I survey the consequences for epistemology of such a scenario, and conclude that many of the striking consequences could be reached even if our experiences don't have high-level contents.

Publication pressure has been touted to promote questionable research practices (QRP) and scientific or research misconduct (RM). However, logically attractively as it is, there is no unequivocal evidence for this notion, and empirical studies have produced conflicting results. Other than difficulties in obtaining unbiased empirical data, a direct causal relationship between perceived publication pressure (PPP) and QRP/RM is inherently difficult to establish, because the former is a complex biopsychosocial construct that is variedly influenced by multiple personal and environmental factors. To (...) effectively address QRP/RM by tackling the sources of PPP would also be difficult because of the competitive nature of the reward and merit system of contemporary science. We might do better with efforts in enhancing knowledge in research ethics and integrity among the practitioners, as well as institutional infrastructures and mechanisms to fairly and efficiently adjudicate cases of QRP/RM. (shrink)

Hofmann and Holm’s recent survey on issues of research misconduct with PhD graduates culminated with a notable conclusion by the authors: ‘ Scientific misconduct seems to be an environmental issue as much as a matter of personal integrity’. Here, we re-emphasise the usefulness of an education-based countermeasure against toxic research environments or cultures that promote unethical practices amongst the younger researchers. We posit that an adequately conducted course in research ethics and integrity, with a good dose of case studies and (...) analyses, can function in a manner that is metaphorically akin to vaccination. The training would cultivate the ability to analyse and build confidence in young researchers in making decisions with sound moral reasoning as well as in speaking up or arguing against pressure and coercions into unacceptable behaviour. A sufficiently large number of young researchers exposed to research ethics trainings would essentially provide a research community some degree of lasting herd immunity at its broadest base. Beyond passive immunity, a crop of research ethics-savvy young researchers could also play active and influential roles as role models for others at their level and perhaps even help correct the wayward attitudes of some senior researchers and initiate prompt action from institutional policy makers in a bottom-up manner. (shrink)

There is an extensive literature on time travel in both philosophy and physics. Part of the great interest of the topic stems from the fact that reasons have been given both for thinking that time travel is physically possible—and for thinking that it is logically impossible! This entry deals primarily with philosophical issues; issues related to the physics of time travel are covered in the separate entries on time travel and modern physics and time machines. We begin with the definitional (...) question: what is time travel? We then turn to the major objection to the possibility of backwards time travel: the Grandfather paradox. Next, issues concerning causation are discussed—and then, issues in the metaphysics of time and change. We end with a discussion of the question why, if backwards time travel will ever occur, we have not been visited by time travellers from the future. (shrink)

Proposes a new model of contractualism based on an interpersonal, deliberative conception of practical reason which answers the twin demands of moral accuracy and explanatory adequacy.

"Rule" adopts the tradition of political philosophy begun by Socrates, refined by Xenophon and Plato. The book concentrates on something the characters call life-without-rule. What would that be? Is it a sort of utopia? How does it differ from anarchy? What makes it so appealing and what are the trade-offs?

This updated edition of Cinema in the Digital Age takes a fresh look at the state of digital cinema. It pays special attention to the ways in which nostalgia for the look and feel of analogue disrupts the aesthetics of the digital image and examines how recent films have disguised and erased their digital foundations.

This work "collects the author's work at the intersection between political philosophy and religion. Alongside his influential earlier essays, it includes nine new essays in which Wolterstorff develops original lines of argument and stakes out novel positions regarding the nature of liberal democracy, human rights, and political authority. Taken together, these positions are an attractive alternative to the so-called public reason liberalism defended by thinkers such as John Rawls"--jacket.

According to Fumerton in his "How Does Perception Justify Belief?", it is misleading or wrong to say that perception is a source of justification for beliefs about the external world. Moreover, reliability does not have an essential role to play here either. I agree, and I explain why in section 1, using novel considerations about evil demon scenarios in which we are radically deceived. According to Fumerton, when it comes to how sensations or experiences supply justification, they do not do (...) so on their own, and instead only do so only in conjunction with support for background beliefs about how the sensations or experiences are best explained. Here I disagree. In section 2, I first clarify the question of whether sensations or experiences provide justification on their own. I then respond to Fumerton’s arguments that use considerations about concept-possession and about how to close possible gaps between experience and truth. In section 3, I develop my main concern about his positive view, where that concern also brings out some of the merits of the view that experiences do justify beliefs about the external world on their own. (shrink)

Unregulated patient treatments and approved clinical trials have been conducted with haematopoietic stem cells and mesenchymal stem cells for children with autism spectrum disorder. While the former direct-to-consumer practice is usually considered rogue and should be legally constrained, regulated clinical trials could also be ethically questionable. Here, we outline principal objections against these trials as they are currently conducted. Notably, these often lack a clear rationale for how transplanted cells may confer a therapeutic benefit in ASD, and thus, have ill-defined (...) therapeutic outcomes. We posit that ambiguous and unsubstantiated descriptions of outcome from such clinical trials may nonetheless appeal to the lay public as being based on authentic scientific findings. These may further fuel caregivers of patients with ASD to pursue unregulated direct-to-consumer treatments, thus exposing them to unnecessary risks. There is, therefore, a moral obligation on the part of those regulating and conducting clinical trials of stem cell-based therapeutic for ASD minors to incorporate clear therapeutic targets, scientific rigour and reporting accuracy in their work. Any further stem cell-based trials for ASD unsupported by significant preclinical advances and particularly sound scientific hypothesis and aims would be ethically indefensible. (shrink)

This volume brings together Nicholas Wolterstorff's essays on epistemology written between 1983 and 2008.

Historically, there has been great deliberation about the limits of human knowledge. Isaac Newton, recognizing his own shortcomings, once described himself as “a boy standing on the seashore... whilst the great ocean of truth lay all underscored before me.” In _Ignorance,_ Nicholas Rescher presents a broad-ranging study that examines the manifestations, consequences, and occasional benefits of ignorance in areas of philosophy, scientific endeavor, and ordinary life. Citing philosophers, theologians, and scientists from Socrates to Steven Hawking, Rescher seeks to uncover (...) the factors that hinder our cognition. Rescher categorizes ignorance as ontologically grounded, or epistemically grounded. He then defines the basis of ignorance: inaccessible data; statistical fogs; secreted information; past data that have left no trace; future discoveries; future contingencies; vagrant predicates; and superior intelligences. Such impediments set limits to inquiry and mean that while we can always extend our existing knowledge-variability here is infinite-there are things that we will never know. Cognitive finitude also hinders our ability to assimilate more than a certain number of facts. We may acquire additional information, but lack the facility to interpret it. More information does not always increase knowledge; it may point us further down the path toward an erroneous conclusion. In light of these deficiencies, Rescher looks to the role of computers in solving problems and expanding our knowledge base, but finds limits to their reasoning capacity. As Rescher's comprehensive study concludes, ignorance itself is a fertile topic for knowledge, and recognizing the boundaries of our comprehension is where wisdom begins. (shrink)

Participation in religious liturgies and rituals is a pervasive and complex human activity. This book discusses the nature of liturgical activity and the various dimensions of such activity. Nicholas Wolterstorff focuses on understanding what liturgical agents actually do and shows religious practice as a rich area for philosophical reflection.

Navigating the ambiguity of invasiveness: is it warranted? Authors De Marco and colleagues have presented a new model on the concept of invasiveness, redefining both its technical definition and practical implementation. 1 While the authors raise valid critiques regarding the discrepancy in definitions, I cannot help but wonder about the purpose of redefining terms for which little confusion, if any, exists? This commentary seeks to scrutinise the rationale supporting the new model in the absence of significant clinical confusion and to (...) explore the implications for clinical practice. What are we trying to solve? Initially, one may notice there is no mention of clinical relevancy, confusion among patients or whether the discrepancy in terms is causing miscommunication. It seems reasonable that some clinical confusion may exist, but so too does a similar imbalance of terms when speaking technically across the specialties; take depression and its definition... (shrink)

A doctrine of intelligent design through evolution is not going to find many friends. It is destined to encounter opposition on all sides. Among scientists the backlog of evolution will have little patience for intelligent design. Among religiousists, many who form intelligent design have their doubts about evolution. In the general public s mind there is a diametrical opposition between evolution and intelligent design: one excludes the other. This book will argue that this view of the matter is not correct, (...) and that in actuality one can regard evolution itself as a pathway to intelligent design. We would do well to go beyond The Origin of Species and taking as our guide such works as W. Wentworth Thomson s On Growth and Form acknowledging that evolutionary adaptation can result in solutions of a sort that intelligence could readily ratify. Accordingly, what the present book seeks is a naturalization of Intelligent Design that sees such design as itself the result of natural and evolutionary processes.". (shrink)

A famous Kant scholar once distinguished two faces of the critical philosophy, one facing the past and less interesting and the other looking forward to the future and still fruitful (Strawson 1966). Rawls's work also has two faces and many of his readers look toward the past, wishing, for instance, that Rawls had been able to provide principles of justice that have the ontological status of categorical imperatives. I thank Andrew Valls for inviting me to clarify points where I diverge (...) from many Rawls scholars. Although this is an academic debate, I believe that the stakes are huge: namely, the future of liberalism in an increasingly interconnected, multicultural world. My response will elaborate how I read Rawls, why I engage Islamic political thought, and how liberals living in Europe or North America may converse with fellow citizens such as Taha Jabir Al-Alwani, who orient themselves politically by the Qur'an rather than, say, the United States Constitution. (shrink)

The ‘interpretive turn’ in twentieth-century hermeneutics rests on the general ontological claim that human reality is the reality of self-interpreting animals. But under the circumstances of advanced modernity, there are aspects of human life, or spheres of human thought and action, that appear to contradict this general thesis, in that they do not present themselves as the doings of self-interpreting animals at all. Of these, the predominant one is the sphere of work or 'productive' action. In face of historical circumstances (...) in which work presents itself as bereft of the meanings that concern self-interpreting animals, hermeneutic philosophy faces a choice: Does it exempt work from the realm of self-interpretive activity, making it an exception to the general ontological thesis; or does it seek to retrieve the hermeneutic provenance of productive action? With a focus on the writings of Gadamer and Ricoeur, the chapter shows that philosophical hermeneutics has vacillated on this issue and it suggests that retrieval of the self-interpretive dimension of productive action is a central task for hermeneutics today. (shrink)

Draws on a broad range of scientific evidence to theorize an evolutionary basis for religion, considering how religion may have served as an essential component of early society survival and that the brain may be inherently inclined toward religious behavior.

Fodor’s radical concept nativism flowed from his view that hypothesis testing is the only route to concept acquisition. Many have successfully objected to the overly-narrow restriction to learning by hypothesis testing. Existing representations can be connected to a new representational vehicle so as to constitute a sustaining mechanism for a new representation, without the new representation thereby being constituted by or structured out of the old. This paper argues that there is also a deeper objection. Connectionism shows that a more (...) fundamental assumption underpinning the debate can also be rejected: the assumption that the development of a new representation must be explained in content-involving terms if innateness is to be avoided. -/- Fodor has argued that connectionism offers no new resources to explain concept acquisition: unless it is merely an uninteresting claim about neural implementation, connectionism’s defining commitment to distributed representations reduces to the claim that some representations are structured out of others (which is the old, problematic research programme). Examination of examples of representational development in connectionist networks shows, however, that some such models explain the development of new representational capacities in non-representational terms. They illustrate the possibility of representational development that is not explicable-by-content. Connectionist representations can be distributed in an important sense, which is incompatible with the assumption of explanation-by-content: they can be distributed over non-representational resources that account for their development. Rejecting the assumption of explanation-by-content thereby opens up a more radical way of rejecting Fodor’s argument for radical concept nativism. (shrink)