This book defends a radical new theory of contingency as a physical phenomenon. Drawing on the many-worlds approach to quantum theory and cutting-edge metaphysics and philosophy of science, it argues that quantum theories are best understood as telling us about the space of genuine possibilities, rather than as telling us solely about actuality. When quantum physics is taken seriously in the way first proposed by Hugh Everett III, it provides the resources for a new systematic metaphysical framework encompassing possibility, necessity, (...) actuality, chance, counterfactuals, and a host of related modal notions. -/- Rationalist metaphysicians argue that the metaphysics of modality is strictly prior to any scientific investigation; metaphysics establishes which worlds are possible, and physics merely checks which of these worlds is actual. Naturalistic metaphysicians respond that science may discover new possibilities and new impossibilities. This book's quantum theory of contingency takes naturalistic metaphysics one step further, allowing that science may discover what it is to be possible. As electromagnetism revealed the nature of light, as acoustics revealed the nature of sound, as statistical mechanics revealed the nature of heat, so quantum physics reveals the nature of contingency. (shrink)

There is a systematic and suggestive analogy between grounding and causation. In my view, this analogy is no coincidence. Grounding and causation are alike because grounding is a type of causation: metaphysical causation. In this paper I defend the identification of grounding with metaphysical causation, drawing on the causation literature to explore systematic connections between grounding and metaphysical dependence counterfactuals, and I outline a non-reductive counterfactual theory of grounding along interventionist lines.

One of the currently popular dogmata of anti-consequentialism is that consequentialism doesn't respect, recognize, or in some important way account for what is referred to as the The charge is often made, but rarely explained in any detail, much less argued for. In this paper I explain what I take to be the most plausible interpretation of the separateness of persons charge. I argue that the charge itself can be deconstructed into at least two further objections to consequentialist theories. These (...) objections amount to (i) the rejection of axiological aggregation, and (ii) the rejection of deontic aggregation. Of these two objections, I argue that the first one, though often made, is untenable. I also argue that the second objection, in its various forms, relies on distinctions whose moral significance is vigorously denied by almost all consequentialist theorists. I thus argue that the separateness of persons objection poses no special threat to consequentialism. (shrink)

This paper outlines a non-reductive counterfactual account of grounding along interventionist lines, and uses the account to argue that taking grounding seriously requires ascribing non-trivial truth-conditions to a range of counterpossible counterfactuals. This result allows for a diagnosis of a route to scepticism about grounding, as deriving at least in part from scepticism about non-trivial counterpossible truth and falsity.

This article explores three ways in which physics may involve counterpossible reasoning. The first way arises when evaluating false theories: to say what the world would be like if the theory were true, we need to evaluate counterfactuals with physically impossible antecedents. The second way relates to the role of counterfactuals in characterizing causal structure: to say what causes what in physics, we need to make reference to physically impossible scenarios. The third way is novel: to model metaphysical dependence in (...) physics, we need to consider counterfactual consequences of metaphysical impossibilities. Physics accordingly bears substantial and surprising counterpossible commitments. (shrink)

Quantum physics is believed to be the fundamental theory underlying our understanding of the physical universe. However, it is based on concepts and principles that have always been difficult to understand and controversial in their interpretation. This book aims to explain these issues using a minimum of technical language and mathematics. After a brief introduction to the ideas of quantum physics, the problems of interpretation are identified and explained. The rest of the book surveys, describes and criticises a range of (...) suggestions that have been made with the aim of resolving these problems; these include the traditional, or 'Copenhagen' interpretation, the possible role of the conscious mind in measurement, and the postulate of parallel universes. This new edition has been revised throughout to take into account developments in this field over the past fifteen years, including the idea of 'consistent histories' to which a completely new chapter is devoted. (shrink)

Distinctions in fundamentality between different levels of description are central to the viability of contemporary decoherence-based Everettian quantum mechanics (EQM). This approach to quantum theory characteristically combines a determinate fundamental reality (one universal wave function) with an indeterminate emergent reality (multiple decoherent worlds). In this chapter I explore how the Everettian appeal to fundamentality and emergence can be understood within existing metaphysical frameworks, identify grounding and concept fundamentality as promising theoretical tools, and use them to characterize a system of explanatory (...) levels (with associated laws of nature) for EQM. This Everettian level structure encompasses and extends the ‘classical’ levels structure. The ‘classical’ levels of physics, chemistry, biology, etc. are recovered, but they are emergent in character and potentially variable across Everett worlds. EQM invokes an additional fundamental level, not present in the classical levels picture, and a novel potential role for self-location in interlevel metaphysics. When given a modal realist interpretation, EQM also makes trouble for supervenience-based approaches to levels. (shrink)

In ‘Quiddistic Knowledge’ (Schaffer in Philos Stud 123:1–32, 2005), Jonathan Schaffer argued influentially against the view that the laws of nature are metaphysically necessary. In this reply I aim to show how a coherent and well-motivated form of necessitarianism can withstand his critique. Modal necessitarianism—the view that the actual laws are the laws of all possible worlds—can do justice to some intuitive motivations for necessitarianism, and it has the resources to respond to all of Schaffer’s objections. It also has certain (...) advantages over contingentism in the domain of modal epistemology. I conclude that necessitarianism about laws remains a live option. (shrink)

David Wallace has given a decision-theoretic argument for the Born Rule in the context of Everettian quantum mechanics. This approach promises to resolve some long-standing problems with probability in EQM, but it has faced plenty of resistance. One kind of objection charges that the requisite notion of decision-theoretic uncertainty is unavailable in the Everettian picture, so that the argument cannot gain any traction; another kind of objection grants the proof’s applicability and targets the premises. In this article I propose some (...) novel principles connecting the physics of EQM with the metaphysics of modality, and argue that in the resulting framework the incoherence problem does not arise. These principles also help to justify one of the most controversial premises of Wallace’s argument, ‘branching indifference’. Absent any a priori reason to align the metaphysics with the physics in some other way, the proposed principles can be adopted on grounds of theoretical utility. The upshot is that Everettians can, after all, make clear sense of objective probability. 1 Introduction2 Setup3 Individualism versus Collectivism4 The Ingredients of Indexicalism5 Indexicalism and Incoherence5.1 The trivialization problem5.2 The uncertainty problem6 Indexicalism and Branching Indifference6.1 Introducing branching indifference6.2 The pragmatic defence of branching indifference6.3 The non-existence defence of branching indifference6.4 The indexicalist defence of branching indifference7 Conclusion. (shrink)

In On the Plurality of Worlds (Lewis 1986), David Lewis imposes a condition on realist theories of modality which he calls ‘plenitude’. Lewis apparently assigns this condition considerable importance, and uses it to motivate his Humean principle of recombination, but he never says exactly what plenitude amounts to. This chapter first sets aside some obvious ways of reconstructing the plenitude criterion which do not fit with the textual evidence. An objection to modal realism due to John Divers and Joseph Melia (...) (Divers and Melia 2002) is diagnosed as equivocating between an overly-demanding plenitude constraint and a weaker constraint which fails to establish their conclusion. An alternative deflationary interpretation of the plenitude condition has it following from an application of standard theoretical virtues to a modal realist’s total theory; Lewis’ correspondence provides new evidence in support of this interpretation. The deflationary plenitude criterion also has broader application, beyond Lewisian modal realism. (shrink)

Alastair Norcross argues that the basic judgments of morality are essentially comparative: alternatives are judged to be better or worse than each other. Notions such as right and wrong are not part of the fundamental subject matter of moral theory, but are constructed in a context-relative fashion out of the basic comparative judgments.

Healthcare Ethics, Law and Professionalism: Essays on the Works of Alastair V Campbell features 15 original essays on bioethics, and healthcare ethics specifically. The volume is in honour of Professor Alastair V Campbell, who was the founding editor of the internationally-renowned Journal of Medical Ethics, and the founding director of three internationally leading centres in bioethics, in Otago, New Zealand, Bristol, UK, and Singapore. Campbell was trained in theology and philosophy and throughout his career worked with colleagues from (...) various disciplines, including law and various branches of healthcare. The diversity of topics and depth of contributors' insights reflect the breadth and impact of Campbell's philosophical work and policy contributions to healthcare ethics. Throughout his long academic career, Campbell's emphasis on healthcare ethics being practice-oriented, yet driven by critical reflection, has shaped the field in vital ways. The chapters are authored by leading scholars in healthcare ethics and law. Directly engaging with Campbell's work and influence, the essays discuss essential questions in healthcare ethics relating to its methodology and teaching, its intersection with law and policy, medical professionalism, religion, and its translation in different cultural settings. Chapters also grapple with specific enduring topics, such as the doctor-patient relationship, justice in health and biomedical research, and treatment of the human body and the dead. (shrink)

Simon Saunders and David Wallace have proposed an attractive semantics for interpreting linguistic communities embedded in an Everettian multiverse. It provides a charitable interpretation of our ordinary talk about the future, and allows us to retain a principle of bivalence for propositions and to retain the law of excluded middle in the logic of propositions about the future. But difficulties arise when it comes to providing an appropriate account of the metaphysics of macroscopic objects and events. I evaluate various metaphysical (...) frameworks which might be combined with the Saunders–Wallace semantics. I conclude that the most appropriate metaphysics to underwrite the semantics renders Everettian quantum mechanics a theory of non-overlapping worlds. (shrink)

There is much to admire in this book. As a rigorous and systematic physics-oriented presentation of an austere empiricist fundamental metaphysics, it has no real rivals. The clarity with which the overall vision is presented will provide a valuable stalking-horse for those who would defend less austere approaches in the future. Esfeld and Deckert never shy away from the radical consequences of their approach, or try to disguise its revisionary nature. I also found several points of agreement with Esfeld and (...) Deckert’s metaphysical outlook. In particular, I thought their form of structural realism sophisticated and plausible and their application of it to contemporary physics salutary. Fundamental metaphysics would be a more respectable discipline if all of its exponents felt the need to show how their preferred ontology plays out in the context of real physics. These points of agreement noted, I will concentrate in these comments on points where I disagree with Esfeld and Deckert. From my perspective, the metaphysical project of the book is subject to two serious objections: firstly, it remains insufficiently naturalistic and overly a prioristic, and secondly, it drains much of the explanatory power out of fundamental physics. (shrink)

In this paper I assess the prospects for combining contemporary Everettian quantum mechanics (EQM) with branching-time semantics in the tradition of Kripke, Prior, Thomason and Belnap. I begin by outlining the salient features of ‘decoherence-based’ EQM, and of the ‘consistent histories’ formalism that is particularly apt for conceptual discussions in EQM. This formalism permits of both ‘branching worlds’ and ‘parallel worlds’ interpretations; the metaphysics of EQM is in this sense underdetermined by the physics. A prominent argument due to Lewis (On (...) the Plurality of Worlds, 1986 ) supports the non-branching interpretation. Belnap et al. (Facing the Future: Agents and Choices in Our Indeterministic World, 2001 ) refer to Lewis’ argument as the ‘Assertion problem’, and propose a pragmatic response to it. I argue that their response is unattractively ad hoc and complex, and that it prevents an Everettian who adopts branching-time semantics from making clear sense of objective probability. The upshot is that Everettians are better off without branching-time semantics. I conclude by discussing and rejecting an alternative possible motivation for branching time. (shrink)

This volume presents twelve original essays on the metaphysics of science, with particular focus on the physics of chance and time. Experts in the field subject familiar approaches to searching critiques, and make bold new proposals in a number of key areas. Together, they set the agenda for future work on the subject.

If the most familiar overlapping interpretation of Everettian quantum mechanics is correct, then each of us is constantly splitting into multiple people. This consequence gives rise to the quantum doomsday argument, which threatens to draw crippling epistemic consequences from EQM. However, a diverging interpretation of EQM undermines the quantum doomsday argument completely. This appears to tell in favour of the diverging interpretation. But it is surprising that a metaphysical question that is apparently underdetermined by the physics should be settled by (...) purely epistemological considerations; and I argue that the positive case for divergence based on the quantum doomsday effect is ultimately unsuccessful. I discuss how some influential treatments of Everettian confirmation handle the quantum doomsday puzzle, and suggest that it can most satisfyingly be resolved via a naturalistic approach to the metaphysics of modality. (shrink)

How should we respond to cases of disagreement where two epistemic agents have the same evidence but come to different conclusions? Adam Elga has provided a Bayesian framework for addressing this question. In this paper, I shall highlight two unfortunate consequences of this framework, which Elga does not anticipate. Both problems derive from a failure of commutativity between application of the equal weight view and updating in the light of other evidence.

Darren Bradley has recently appealed to observation selection effects to argue that conditionalization presents no special problem for Everettian quantum mechanics, and to defend the ‘halfer’ answer to the puzzle of Sleeping Beauty. I assess Bradley’s arguments and conclude that while he is right about confirmation in Everettian quantum mechanics, he is wrong about Sleeping Beauty. This result is doubly good news for Everettians: they can endorse Bayesian confirmation theory without qualification, but they are not thereby compelled to adopt the (...) unpopular ‘halfer’ answer in Sleeping Beauty. These considerations suggest that objective chance is playing an important and under-appreciated role in Sleeping Beauty. 1 Introduction2 Confirmation in Everettian Quantum Mechanics3 Sleeping Beauty4 The Selection Model5 Bradley’s Argument6 The Right Route to ⅓7 The Breakdown of the Analogy8 Alternative Diagnoses9 God’s Gambling Game10 Non-chancy Sleeping Beauty Cases11 Conclusion. (shrink)

Darren Bradley has recently appealed to observation selection effects to argue that conditionalization presents no special problem for Everettian quantum mechanics, and to defend the ‘halfer’ answer to the puzzle of Sleeping Beauty. I assess Bradley’s arguments and conclude that while he is right about confirmation in Everettian quantum mechanics, he is wrong about Sleeping Beauty. This result is doubly good news for Everettians: they can endorse Bayesian confirmation theory without qualification, but they are not thereby compelled to adopt the (...) unpopular ‘halfer’ answer in Sleeping Beauty. These considerations suggest that objective chance is playing an important and under-appreciated role in Sleeping Beauty. (shrink)

By the 1880s it had become clear that the intellectual tide in Britain was turning against the idea of a minimal state. Under the influence of the New Idealists, the Liberal Party, once the champion of individual liberty, had changed into an organ for interventionist legislation. Challenging this movement was an assortment of anti-collectivists including Old Liberals, Tories, and radical individualists. Spearheading the defence of individualism was the 10th Earl of Wemyss, Francis Wemyss-Charteris-Douglas. Most famous for his role in the (...) formation of the Liberty and Property Defence League, Wemyss worked tirelessly in parliament to obstruct legislation deemed inimical to liberty, as well as to organise a mass educational effort to instruct the public about the errors of collectivist philosophy and policy. This paper examines the role Wemyss played within late Victorian individualism and considers how the melding of traditionalism and individualism provided an intellectual home for libertarianism on the Right. (shrink)

Western Political Thought in Dialogue with Asia is a unique collection of essays that examines the exchange of political ideas between Western Europe and Asia from the Middle Ages to the early twentieth century. The contributors to the volume call for globalizing the scope of research and teaching in the history of political thought.

In his book Objective Becoming (Skow 2015), Bradford Skow has offered a rich and systematic treatment of the passage of time. We learn much about what objective passage could and could not amount to from engaging with his careful work. Skow’s overall conclusion is that the ‘block universe’ deflationary theory of passage is stronger than any currently available version of the recently-popular moving spotlight theory of temporal passage. To help establish this conclusion, Skow provides a taxonomy of theories of temporal (...) passage, including some new and unfamiliar theories that he classifies as versions of the moving spotlight view. These new theories are worthy of further study; however, in this commentary I will argue that they suffer from some problems that render them uncongenial to committed believers in temporal passage (Sections 2–5). I’ll also make a few brief remarks about some other arguments in the book, concerning branching time (Section 6), relativistic presentness (Section 7), and temporal experience (Section 8). (shrink)

The evolutionary framework suggested by Müller & Schumann (M&S) can be extended further by considering drug-taking in terms of Niche Construction Theory (NCT). It is suggested here that genetic and environmental components of addiction are modified by cultural acceptance of the advantages of non-addicted drug taking and the legitimate supply of performance-enhancing drugs. This may then reduce the prevalence of addiction.

This volume is a collection of cutting-edge research papers in scientifically informed metaphysics, tackling a range of philosophical puzzles which have emerged from recent work on chance and temporal asymmetry. How do the probabilities found in fundamental physics and the probabilities of the special sciences relate to one another? How can we account for the normative significance of chance? Can constraints on the initial conditions of the universe underwrite the second law of thermodynamics, and potentially also all other lawlike regularities? (...) How does contemporary quantum theory bear on debates over the nature of chance and the arrow of time? What grounds do we have for believing in a fundamental temporal direction, or flow? And how do all these questions connect up with one another? The aim of the volume is both to survey and summarize recent debates about chance and temporal asymmetry and to push them forward. The authors bring perspectives from metaphysics, from philosophy of physics and from philosophy of probability. Mainstream approaches are subjected to searching new critiques, and bold new proposals are made concerning (inter alia) the semantics of chance-attributions, the justification of the Principal Principle connecting chance and degree of belief, the limits on inter-theoretic reduction and the source of the temporal asymmetry of human experience. (shrink)

Dispositions can combine as vector sums. Recent authors on dispositions, such as George Molnar and Stephen Mumford, have responded to this feature of dispositions by introducing a distinction between effects and contributions to effects, and by identifying disposition-manifestations with the latter. But some have been sceptical of the reality or knowability of component vectors; Jennifer McKitrick (forthcoming) presses these concerns against the conception of manifestations as contributions to effects. In this paper, I aim to respond to McKitrick's arguments and to (...) defend the metaphysical and epistemological propriety of component vectors. My strategy appeals to varying kinematic frames of reference. By transforming to the appropriate non-inertial frame, component acceleration vectors can be transformed into resultant acceleration vectors, and in such frames they become directly observable. Being a component acceleration vector and being a resultant acceleration vector are both frame-dependent properties of properties; they are not to be thought of as intrinsic or fundamental properties of an acceleration vector, but as artefacts of our frame-dependent notation for representing vector quantities. To conclude the paper, I defend the view proposed against two styles of objection. The first objection resurrects scepticism about component vectors as scepticism about fundamental component vectors. The second objection questions the need for reference frames in the explanation by invoking a 'counterfactual' theory of contributions. (shrink)