I propose an account of probability in the Everett interpretation of quantum mechanics. According to the account, probabilities are objective chances of centered propositions. As I show, the account solves a number of problems concerning the role of probability in the Everett interpretation. It also challenges an implicit assumption, concerning the aim and scope of fundamental physical theories, that is made throughout the philosophy of physics literature.

Everettian quantum mechanics tells us that the fundamental dynamics of the universe are deterministic. So what are the `probabilities' that the Born rule describes? One popular answer has been to treat these probabilities as rational credences. A recent alternative, Isaac Wilhelm's centered Everett Interpretation (CEI), takes the Born probabilities to be centered chances: the objective chances that some centered propositions are true. Thus, the CEI challenges the `orthodox assumption’ that fundamental physical laws concern only uncentered facts. I provide (...) three arguments against the centered Everett Interpretation. First, I argue that the CEI is in apparent tension with a significant motivation for adopting Everettian quantum mechanics: rejecting the attribution of special significance to observers or agents in fundamental physics. I suggest the CEI can avoid this tension, but only at the cost of sacrificing its central claim that there are objective chances in an Everettian multiverse. My second argument concerns the CEI’s claim that the centered Born rule is a fundamental physical law. I provide two plausible notions of fundamentality for physical laws, and I argue that the centered Born rule satisfies neither. My final argument is that the CEI’s branch-relative laws cannot explain or constrain an agent’s rational credences in the way that the CEI claims. (shrink)

This article offers a simple technical resolution to the problem of induction, which is to say that general facts are not always inferred from observations of particular facts, but are themselves sometimes defeasibly observed. The article suggests a holistic account of observation that allows for general statements in empirical theories to be interpreted as observation reports, in place of the common but arguably obsolete idea that observations are exclusively particular. Predictions and other particular statements about unobservable facts can then appear (...) as deductive consequences of such general observation statements, rather than inductive consequences of other particular statements. This semantic shift resolves the problem by eliminating induction as a basic form of inference, and folding the justification of general beliefs into the more basic problem of perception. (shrink)

It is argued that those who defend the Everett, or ‘many-worlds’, interpretation of quantum mechanics should embrace what we call the general quantum theory of open systems (GT) as the proper framework in which to conduct foundational and philosophical investigations in quantum physics. GT is a wider dynamical framework than its alternative, standard quantum theory (ST). This is true even though GT makes no modifications to the quantum formalism. GT rather takes a different view, what we call the (...) open systems view, of the formalism; i.e., in GT, the dynamics of systems whose physical states are fundamentally represented by density operators are represented as fundamentally open as specified by an in general non-unitary dynamical map. This includes, in principle, the dynamics of the universe as a whole. We argue that the more general dynamics describable in GT can be physically motivated, that there is as much prima facie empirical support for GT as there is for ST, and that GT could be fully in the spirit of the Everett interpretation—that there might, in short, be little reason for an Everettian not to embrace the more general theoretical landscape that GT allows one to explore. (shrink)

In this paper I provide some formal schemas for the analysis of vague predicates in terms of a set of semantic relations other than classical synonymy, including weak synonymy (as between "large" and "huge"), antonymy (as between "large" and "small"), relativity (as between "large" and "large for a dog"), and a kind of supervenience (as between "large" and "wide" or "long"). All of these relations are representable in the simple comparative logic CL, in accordance with the basic formula: the more (...) something is F, the more (or less) it is G. I use Carnapian meaning postulates to define these relations as constraints on interpretations of the formal language of CL. (shrink)

We offer a novel interpretation of the argumentative role that Meditation IV plays within the whole of the Meditations. This new interpretation clarifies several otherwise head-scratching claims that Descartes makes about Meditation IV, and it fully exonerates the Fourth Meditation from either raising or exacerbating Descartes’ circularity problems.

Sometimes we learn what the world is like, and sometimes we learn where in the world we are. Are there any interesting differences between the two kinds of cases? The main aim of this article is to argue that learning where we are in the world brings into view the same kind of observation selection effects that operate when sampling from a population. I will first explain what observation selection effects are ( Section 1 ) and how they are relevant (...) to learning where we are in the world ( Section 2 ). I will show how measurements in the Many Worlds Interpretation of quantum mechanics can be understood as learning where you are in the world via some observation selection effect ( Section 3 ). I will apply a similar argument to the Sleeping Beauty Problem ( Section 4 ) and explain what I take the significance of the analogy to be ( Section 5 ). Finally, I will defend the Restricted Principle of Indifference on which some of my arguments depend ( Section 6 ). (shrink)

The centered Everett interpretation solves a problem that various approaches to quantum theory face. In this paper, I continue developing the theory underlying that solution. In particular, I defend the centered Everett interpretation against a few objections, and I provide additional motivation for some of its key features.

The many worlds interpretation of quantum mechanics (MWI) states that the world we live in is just one among many parallel worlds. It is widely believed that because of this commitment to parallel worlds, the MWI violates common sense. Some go so far as to reject the MWI on this basis. This is despite its myriad of advantages to physics (e.g. consistency with relativity theory, mathematical simplicity, realism, determinism, etc.). Here, we make the case that common sense in fact (...) favors the MWI. We argue that causal explanations are commonsensical only when they are local causal explanations. We present several quantum mechanical experiments that seem to exhibit nonlocal “action at a distance”. Under the assumption that only one world exists, these experiments seem immune to local causal explanation. However, we show that the MWI, by taking all worlds together, can provide local causal explanations of the experiments. The MWI therefore restores common sense to physical explanation. (shrink)

This paper explores the physical and metaphysical implications of time travel, focusing on the possibility of changing the past, through a comparative analysis of David Lewis' modal realism and Everett's many-worlds interpretation of quantum mechanics. The existence of closed timelike curves (CTCs) in certain solutions to Einstein's field equations provides a theoretical basis for the possibility of backwards time travel, but this leads to a range of paradoxes, most notably the grandfather paradox. David Lewis argues that time travel (...) must maintain consistency and that the past cannot be changed, even if time travel were possible. His view is supported by his modal realism, which posits the existence of a plurality of possible worlds. In contrast, Everett's many-worlds interpretation, which holds that quantum mechanics describes a multiverse of branching realities, might seem to allow for the possibility of multiple, inconsistent histories. By examining these two ontological frameworks, this paper aims to shed light on the paradoxes of time travel and to explore whether the many-worlds interpretation provides a more satisfactory resolution to these paradoxes than Lewis' modal realism. It is argued that while Lewis' view provides a coherent model for maintaining consistency in time travel, Everett's interpretation may offer a more physically grounded and philosophically compelling account of the metaphysics of time travel. The paper concludes by suggesting that the many-worlds interpretation, by locating the branching of timelines within the structure of quantum mechanics itself, may provide a more promising framework for understanding the possibility and implications of time travel than Lewis' modal realism. However, significant questions remain about the nature of personal identity and free will in a branching multiverse. This comparative analysis aims to contribute to the ongoing debate about the metaphysical possibility of time travel and to highlight the value of engaging with interpretations of quantum mechanics in this context. Keywords: time travel, closed timelike curves, modal realism, many-worlds interpretation, grandfather paradox, metaphysics of time. (shrink)

This paper connects the hard problem of consciousness to the interpretation of quantum mechanics. It shows that constitutive Russellian pan(proto)psychism (CRP) is compatible with Everett’s relative-state (RS) interpretation. Despite targeting different problems, CRP and RS are related, for they both establish symmetry between micro- and macrosystems, and both call for a deflationary account of Subject. The paper starts from formal arguments that demonstrate the incompatibility of CRP with alternative interpretations of quantum mechanics, followed by showing that RS (...) entails Russellian pan(proto)psychism. Therefore, CRP and RS are mutually supportive. It then provides a unified ontological picture by combining CRP and RS. The challenge faced by CRP, the combination problem, can be resolved by adopting a RS version of quantum mechanics. Technically, this is achieved by a co-consciousness relation capable of explaining the difference between first-person and third-person perspectives. The hierarchical structure of the relation removes any concern on the structural mismatch between the physical and the phenomenal. (shrink)

Despite its enormous practical success, many physicists and philosophers alike agree that the quantum theory is full of contradictions and paradoxes which are difficult to solve consistently. Even after 90 years, the experts themselves still do not all agree what to make of it. The area of disagreement centers primarily around the problem of describing observations. Formally, the so-called quantum measurement problem can be defined as follows: the result of a measurement is a superposition of vectors, each representing the quantity (...) being observed as having one of its possible values. The question that has to be answered is: how this superposition can be reconciled with the fact that in practice we only observe one value. How is the measuring instrument prodded into making up its mind which value it has observed? Among some alternatives to resolve the above QM measurement problem, a very counterintuitive one was suggested by Hugh Everett in his 1955 Princeton dissertation, which was subsequently called the Many-Worlds Interpretation of QM (MWI). In this paper we will not discuss all possible scenarios to solve the measurement problem, but we will only shortly discuss Everett’s MWI, because it has led to heated debates on possibility of multiverses, beyond the Universe we live in. We also discuss two alternatives against MWI proposal: (a) the so-called scale symmetry theory, (b) the Maxwell-Dirac isomorphism. In last section, we also discuss shortly MWI hypothesis from philosophical perspective. (shrink)

The persistent interpretation problem for quantum mechanics may indicate an unwillingness to consider unpalatable assumptions that could open the way toward progress. With this in mind, I focus on the work of David Bohm, whose earlier work has been more influential than that of his later. As I’ll discuss, I believe two assumptions play a strong role in explaining the disparity: 1) that theories in physics must be grounded in mathematical structure and 2) that consciousness must supervene on material (...) processes. I’ll argue that the first assumption appears to lead us toward Everett’s many worlds interpretation, which suggests a red flag. I’ll also argue that the second assumption is suspect due to the persistent explanatory gap for consciousness. Later, I explore ways that Bohm’s later work holds some promise in providing a better fit with our world, both phenomenologically and empirically. Also, I’ll address the possible problem of realism. (shrink)

The modern Everett interpretation of quantum mechanics describes an emergent multiverse. The goal of this paper is to provide a perspicuous characterisation of how the multiverse emerges making use of a recent account of (weak) ontological emergence. This will be cashed out with a case study that identifies decoherence as the mechanism for emergence. The greater metaphysical clarity enables the rebuttal of critiques due to Baker (2007) and Dawid and Th\'ebault (2015) that cast the emergent multiverse ontology as (...) incoherent; responses are also offered to challenges to the Everettian approach from Maudlin (2010) and Monton (2013). (shrink)

It is proposed a critique of existing interpretations of quantum mechanics, both anti-realistic and realistic, and, in particular, the Copenhagen interpretation, the interpretations with hidden variables, the metaphysical interpretation of H. Everett’s interpretation, the many-worlds interpretation by D. Wallace, QBism by C. Fuchs, D. Mermin and R. Schack, the relational interpretation by C. Rovelli, neo-Kantian and phenomenological interpretations by M. Bitbol, the informational interpretation by A. Zeilinger, the Nobel Prize Winner in Physics 2022, (...) and others. As is known compared to classical physics, quantum mechanics is a new physical paradigm. The author argues that from a philosophical point of view quantum mechanics is an anomaly within the paradigm of (post)modern philosophy. A new approach to understanding quantum mechanics and resolving its paradoxes, rejecting the assumptions and prejudices of (post)modern philosophy, is proposed – contextual quantum realism (CQR). It is a moderately deflationary approach that combines elements of (neo-)Copenhagen, informational and realist interpretations and recognizes the possibility of knowing the things themselves. From the point of view of CQR, the measurement problem – the basic problem of philosophy of quantum mechanics – is a pseudo-problem . (shrink)

This article defends the Doomsday Argument, the Halfer Position in Sleeping Beauty, the Fine-Tuning Argument, and the applicability of Bayesian confirmation theory to the Everett interpretation of quantum mechanics. It will argue that all four problems have the same structure, and it gives a unified treatment that uses simple models of the cases and no controversial assumptions about confirmation or self-locating evidence. The article will argue that the troublesome feature of all these cases is not self-location but selection (...) effects. (shrink)

One might suppose that Everettian quantum mechanics (EQM) is inhospitable to metaphysial indeterminacy (MI), given that, as A. Wilson (2020) puts it, "the central idea of EQM is to replace indeterminacy with multiplicity" (77). But as Wilson goes on to suggest, the popular decoherence-based understanding of EQM (henceforth: DEQM) appears to admit of indeterminacy in both world number and world nature, where the latter indeterminacy---our focus here---is plausibly metaphysical. After a brief presentation of DEQM (S1), we bolster the case for (...) there being MI in world nature in DEQM (S2). The remainder of the paper is devoted to a comparative assessment of the two main approaches to MI for purposes of accommodating this MI---namely, a metaphysical supervaluationist approach (as per Barnes and Williams 2011) and a determinable-based approach (as per Wilson 2013 and Calosi and Wilson 2018 and 2021). We briefly describe each approach (S3), then offer arguments in favour of a determinable-based approach to world nature MI in DEQM (S4). (shrink)

Privileged-perspective realism (PPR) is a version of metaphysical realism that takes certain irreducibly perspectival facts to be partly constitutive of reality. PPR asserts that there is a single metaphysically privileged standpoint from which these perspectival facts obtain. This chapter discusses several views that fall under the category of privileged-perspective realism. These include presentism, which is PPR about tensed facts, and non-multiverse interpretations of quantum mechanics, which the chapter argues, constitute PPR about world-indexed facts. Using the framework of the bird perspective (...) and the frog perspective, it argues that PPR views methodologically treat the frog perspective as metaphysically primary. This chapter considers case studies of metaphysical interpretations of special relativity and quantum mechanics in order to demonstrate that such motivations for PPR are non-naturalistic. Further, it considers psychological factors that motivate the appeal of PPR views and offers naturalistic explanations of why we should not expect them to produce an adequate metaphysics of science. (shrink)

This thesis develops a detailed account of the emergence of for all practical purposes continuous, quasi-classical world histories from the discontinuous, stochastic micro dynamics of Minimal Bohmian Mechanics (MBM). MBM is a non-relativistic quantum theory. It results from excising the guiding equation from standard Bohmian Mechanics (BM) and reinterpreting the quantum equilibrium hypothesis as a stochastic guidance law for the random actualization of configurations of Bohmian particles. On MBM, there are no continuous trajectories linking up individual configurations. Instead, individual configurations (...) are actualized independently of each other, carving out the decoherence-induced branching structure of the universal wave function. Yet, by contrast to the Everett interpretation, branches of the universal wave function are not actualized in parallel, i.e. all at the same time. Rather, world branches, on MBM, are actualized sequentially. -/- For an introduction to MBM, the transition from BM to MBM is described, and their empirical equivalence is established. I present the conditions under which MBM can be classified as a primitive ontology (PO) theory, regarded as crucial for the acceptance of a theory as Bohmian by many proponents of BM. While rendering MBM compatible with the PO approach, it must not fall prey to the problem of communication, arising from the two-space reading of BM. -/- The issue of temporal solipsism, identified by Bell as a serious problem for his “Everett (?) theory” – the historic predecessor of MBM – is discussed. I argue that Barbour’s time capsule approach does not provide a satisfactory solution. In particular, his adopting a more than minimal psychophysical parallelism between brain processes and experience of macroscopic change is argued to be reasonable in light of our current best neuroscience, yet problematic for theories relying solely on time capsules, understood as highly structured, individual, internally static configurations. As a solution, I introduce worlds, and world histories, as key concepts in providing a link between MBM’s micro dynamics and macroscopic phenomena. Worlds, other than time capsules, are coarse-grained regions in phase- or configuration space, defined as sets of possible micro states satisfying a relation of sufficient similarity from a macroscopic perspective, with respect to a given micro state. Hence, worlds may overlap. -/- I argue that worlds thus construed are a reasonable option for replacing the disjoint macro regions of phase space, resulting from the usual way of partitioning phase space in the standard framework of Boltzmannian statistical mechanics. This move solves the issue of discontinuous change of macro variables upon the micro state crossing the boundary between different macro regions. -/- I adapt this move for MBM’s discontinuous micro dynamics in configuration space. Issues revolving around the microscopic-macroscopic distinction, particle identity, impenetrability and haecceity in light of the desideratum of particle number conservation, etc., are discussed. I provide a detailed explanation of how overlapping worlds in MBM form world histories, thereby linking up macroscopically distinct worlds. Thus, the problem of temporal solipsism is resolved in a way that is compatible with a more than minimal psychophysical parallelism. (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)

Thinking about time travel is an entertaining way to explore how to understand time and its location in the broad conceptual landscape that includes causation, fate, action, possibility, experience, and reality. It is uncontroversial that time travel towards the future exists, and time travel to the past is generally recognized as permitted by Einstein’s general theory of relativity, though no one knows yet whether nature truly allows it. Coherent time travel stories have added flair to traditional debates over the metaphysical (...) status of the past, the reality of temporal passage, and the existence of free will. Moreover, plausible models of time travel and time machines can be used to investigate the subtle relation between space-time structure and causality. -/- It surveys some philosophical issues concerning time travel and should serves as a quick introduction. It includes a new and improved way to define a time machine. (shrink)

How should we update our beliefs when we learn new evidence? Bayesian confirmation theory provides a widely accepted and well understood answer – we should conditionalize. But this theory has a problem with self-locating beliefs, beliefs that tell you where you are in the world, as opposed to what the world is like. To see the problem, consider your current belief that it is January. You might be absolutely, 100%, sure that it is January. But you will soon believe it (...) is February. This type of belief change cannot be modelled by conditionalization. We need some new principles of belief change for this kind of case, which I call belief mutation. In part 1, I defend the Relevance-Limiting Thesis, which says that a change in a purely self-locating belief of the kind that results in belief mutation should not shift your degree of belief in a non-self-locating belief, which can only change by conditionalization. My method is to give detailed analyses of the puzzles which threaten this thesis: Duplication, Sleeping Beauty, and The Prisoner. This also requires giving my own theory of observation selection effects. In part 2, I argue that when self-locating evidence is learnt from a position of uncertainty, it should be conditionalized on in the normal way. I defend this position by applying it to various cases where such evidence is found. I defend the Halfer position in Sleeping Beauty, and I defend the Doomsday Argument and the Fine-Tuning Argument. (shrink)

After some suggestions about how to clarify the confused metaphysical distinctions between dispositional and non-dispositional or categorical properties, I review some of the main interpretations of QM in order to show that – with the relevant exception of Bohm’s minimalist interpretation – quantum ontology is irreducibly dispositional. Such an irreducible character of dispositions must be explained differently in different interpretations, but the reducibility of the contextual properties in the case of Bohmian mechanics is guaranteed by the fact that the (...) positions of particles play the role of the categorical basis, a role that in other interpretations cannot be filled by anything else. In Bohr’s and Everett-type interpretations, dispositionalism is instrumentalism in disguise. (shrink)

The second law of thermodynamics is traditionally interpreted as a coarse-grained result of classical mechanics. Recently its relation with quantum mechanical processes such as decoherence and measurement has been revealed in literature. In this paper we will formulate the second law and the associated time irreversibility following Everett’s idea: systems entangled with an object getting to know the branch in which they live. Accounting for this self-locating knowledge, we get two forms of entropy: objective entropy measuring the uncertainty of (...) the state of the object alone, and subjective entropy measuring the information carried by the self-locating knowledge. By showing that the summation of the two forms of entropy is a conserved and perspective-free quantity, we interpret the second law as a statement of irreversibility in knowledge acquisition. This essentially derives the thermodynamic arrow of time from the subjective arrow of time, and provides a unified explanation for varieties of the second law, as well as the past hypothesis. (shrink)

A longstanding issue in attempts to understand the Everett (Many-Worlds) approach to quantum mechanics is the origin of the Born rule: why is the probability given by the square of the amplitude? Following Vaidman, we note that observers are in a position of self-locating uncertainty during the period between the branches of the wave function splitting via decoherence and the observer registering the outcome of the measurement. In this period it is tempting to regard each branch as equiprobable, but (...) we argue that the temptation should be resisted. Applying lessons from this analysis, we demonstrate (using methods similar to those of Zurek's envariance-based derivation) that the Born rule is the uniquely rational way of apportioning credence in Everettian quantum mechanics. In doing so, we rely on a single key principle: changes purely to the environment do not affect the probabilities one ought to assign to measurement outcomes in a local subsystem. We arrive at a method for assigning probabilities in cases that involve both classical and quantum self-locating uncertainty. This method provides unique answers to quantum Sleeping Beauty problems, as well as a well-defined procedure for calculating probabilities in quantum cosmological multiverses with multiple similar observers. (shrink)

This paper shows that several live philosophical and scientific hypotheses – including the holographic principle and multiverse theory in quantum physics, and eternalism and mind-body dualism in philosophy – jointly imply an audacious new theory of free will. This new theory, "Libertarian Compatibilism", holds that the physical world is an eternally existing array of two-dimensional information – a vast number of possible pasts, presents, and futures – and the mind a nonphysical entity or set of properties that "read" that physical (...) information off to subjective conscious awareness (in much the same way that a song written on an ordinary compact-disc is only played when read by an outside medium, i.e. a CD-player). According to this theory, every possible physical “timeline” in the multiverse may be fully physically deterministic or physically-causally closed but each person’s consciousness still entirely free to choose, ex nihilo, outside of the physical order, which physically-closed timeline is experienced by conscious observers. Although Libertarian Compatibilism is admittedly fantastic, I show that it not only follows from several live scientific and philosophical hypotheses, I also show that it (A) is a far more explanatorily powerful model of quantum mechanics than more traditional interpretations (e.g. the Copenhagen, Everett, and Bohmian interpretations), (B) makes determinate, testable empirical predictions in quantum theory, and finally, (C) predicts and explains the very existence of a number of philosophical debates and positions in the philosophy of mind, time, personal identity, and free will. First, I show that whereas traditional interpretations of quantum mechanics are all philosophically problematic and roughly as ontologically “extravagant” as Libertarian Compatibilism – in that they all posit “unseen” processes – Libertarian Compatibilism is nearly identical in structure to the only working simulation that human beings have ever constructed capable of reproducing (and so explaining) every general feature of quantum mechanics we perceive: namely, massive-multiplayer-online-roleplaying videogames (or MMORPGs). Although I am not the first to suggest that our world is akin to a computer simulation, I show that existing MMORPGs (online simulations we have already created) actually reproduce every general feature of quantum mechanics within their simulated-world reference-frames. Second, I show that existing MMORPGs also replicate (and so explain) many philosophical problems we face in the philosophy of mind, time, personal identity, and free will – all while conforming to the Libertarian Compatibilist model of reality. -/- I conclude, as such, that as fantastic and metaphysically extravagant as Libertarian Compatibilism may initially seem, it may well be true. It explains a number of features of our reality that no other physical or metaphysical theory does. (shrink)

We provide a derivation of the Born Rule in the context of the Everett (Many-Worlds) approach to quantum mechanics. Our argument is based on the idea of self-locating uncertainty: in the period between the wave function branching via decoherence and an observer registering the outcome of the measurement, that observer can know the state of the universe precisely without knowing which branch they are on. We show that there is a uniquely rational way to apportion credence in such cases, (...) which leads directly to the Born Rule. Our analysis generalizes straightforwardly to cases of combined classical and quantum self-locating uncertainty, as in the cosmological multiverse. (shrink)

The paper takes up Bell's “Everett theory” and develops it further. The resulting theory is about the system of all particles in the universe, each located in ordinary, 3-dimensional space. This many-particle system as a whole performs random jumps through 3N-dimensional configuration space – hence “Tychistic Bohmian Mechanics”. The distribution of its spontaneous localisations in configuration space is given by the Born Rule probability measure for the universal wavefunction. Contra Bell, the theory is argued to satisfy the minimal desiderata (...) for a Bohmian theory within the Primitive Ontology framework. TBM's formalism is that of ordinary Bohmian Mechanics, without the postulate of continuous particle trajectories and their deterministic dynamics. This “rump formalism” receives, however, a different interpretation. We defend TBM as an empirically adequate and coherent quantum theory. Objections voiced by Bell and Maudlin are rebutted. The “for all practical purposes”-classical, Everettian worlds exist sequentially in TBM. In a temporally coarse-grained sense, they quasi-persist. By contrast, the individual particles themselves cease to persist. (shrink)

The many-worlds view is one of the most discussed “interpretations” of quantum mechanics. As is well known, this view has some very controversial and much discussed aspects. This paper focuses on one particular problem arising from the combination of quantum mechanics with Special Relativity. It turns out that the ontology of the many-worlds view – the account of what there is and what branches of the universe exist – is relative to inertial frames. If one wants to avoid relativizing ontology, (...) one has to argue either that there is an additional source of branching due to Special Relativity and thus additional branches or worlds. Or one has to argue that there are not only many worlds but also many universes ; there is thus not only one tree of many world-branches but many frame-specific trees, a “forest” of many world-trees. The main problem here is how one can understand all or any of this. (shrink)

This paper provides a brief introduction to quantum theory and the proceeds to discuss the different ways in which the relationship between quantum theory and mind/consciousness is seen in some of the main alternative interpretations of quantum theory namely by Bohr; von Neumann; Penrose: Everett; and Bohm and Hiley. It briefly considers how qualia might be explained in a quantum framework, and makes a connection to research on quantum biology, quantum cognition and quantum computation. The paper notes that it (...) is widely agreed that conscious experience has dynamical and holistic features. It asks whether these features might in some way be a reflection of the dynamic and holistic quantum physical processes associated with the brain that may underlie (and make possible) the more mechanistic neurophysiological processes that contemporary cognitive neuroscience is measuring. If so, these macroscopic processes would be a kind of shadow, or amplification of the results of quantum processes at a deeper (pre-spatial or "implicate") level where our minds and conscious experience essentially live and unfold. The macroscopic, mechanistic level is of course necessary for communication, cognition and life as we know it, including science; but perhaps the experiencing (consciousness) of that world and the initiation of our actions takes place at a more subtle, non-mechanical level of the physical world, which quantum theory has begun to discover. At the very least a quantum perspective will help a “classical” consciousness theorist to become better aware of some of the hidden assumptions in his or her approach. Given that consciousness is widely thought to be a “hard” problem, its solution may well require us to question and revise some of our assumptions that now seem to us completely obvious. This is what quantum theory is all about – learning, on the basis of scientific experiments, to question the “obvious” truths about the nature of the physical world and to come up with more coherent alternatives. (shrink)

This paper investigates the historical origin and ancestors of typicality, which is now a central concept in Boltzmannian Statistical Mechanics and Bohmian Mechanics. Although Ludwig Boltzmann did not use the word typicality, its main idea, namely, that something happens almost always or is valid for almost all cases, plays a crucial role for his explanation of how thermodynamic systems approach equilibrium. At the beginning of the 20th century, the focus on almost always or almost everywhere was fruitful for developing measure (...) theory and probability theory. It was apparently Hugh Everett III who first mentioned typicality in physics in 1957 while searching for a justification of the Born rule in his interpretation of quantum mechanics. The historically closest concept before these developments is moral certainty, which was invented by the medieval French theologian Jean Gerson, and it became a standard concept at least until the Age of Enlightenment, when Jakob Bernoulli proved the Law of Large numbers. (shrink)

What is a physical object according to the theory of quantum mechanics? The first answer to be considered is that given by Bohr in terms of the concept of complementarity. This interpretation is illustrated by way of an example, the two slit experiment, which highlights some of the associated problems of ontology. One such problem is the so-called problem of measurement or observation. Various interpretations of measurement in Quantum Theory, including those of Heisenberg, von Neumann, Everett and Bohr, (...) are compared and contrasted. A second problem concerns whether or not QT can be considered complete and therefore satisfactory as a basis for physics. Various attempts to complete QT by means of the addition of ‘hidden variables’ to the quantum mechanical state function are considered and their aims and achievements assessed. Finally, we investigate some of the characteristic ontological problems for the orthodox interpretation of Relativistic Quantum Theory. -/- . (shrink)

Tous les chercheurs intéressés aux fondements de la théorie quantique s’entendent sur le fait que celle-ci a profondément modifié notre conception de la réalité. Là s’arrête, toutefois, le consensus. Le formalisme de la théorie, non problématique, donne lieu à plusieurs interprétations très différentes, qui ont chacune des conséquences sur la notion de réalité. Cet article analyse comment l’interprétation de Copenhague, l’effondrement du vecteur d’état de von Neumann, l’onde pilote de Bohm et de Broglie et les mondes multiples d’Everett modifient, (...) chacun à sa manière, la conception classique de la réalité, dont le caractère local, en particulier, requiert une révision. (shrink)

A non-relativistic quantum mechanical theory is proposed that describes the universe as a continuum of worlds whose mutual interference gives rise to quantum phenomena. A logical framework is introduced to properly deal with propositions about objects in a multiplicity of worlds. In this logical framework, the continuum of worlds is treated in analogy to the continuum of time points; both “time” and “world” are considered as mutually independent modes of existence. The theory combines elements of Bohmian mechanics and of (...) class='Hi'>Everett’s many-worlds interpretation; it has a clear ontology and a set of precisely defined postulates from where the predictions of standard quantum mechanics can be derived. Probability as given by the Born rule emerges as a consequence of insufficient knowledge of observers about which world it is that they live in. The theory describes a continuum of worlds rather than a single world or a discrete set of worlds, so it is similar in spirit to many-worlds interpretations based on Everett’s approach, without being actually reducible to these. In particular, there is no splitting of worlds, which is a typical feature of Everett-type theories. Altogether, the theory explains (1) the subjective occurrence of probabilities, (2) their quantitative value as given by the Born rule, and (3) the apparently random “collapse of the wavefunction” caused by the measurement, while still being an objectively deterministic theory. (shrink)

This paper aims to determine whether we can locate temporal passage in a non-dynamical (block universe) world. In particular, we seek to determine both whether temporal passage can be located somewhere in our world if it is non-dynamical, and also to home in on where in such a world temporal passage can be located, if it can be located anywhere. We investigate this question by seeking to determine, across three experiments, whether the folk concept of temporal passage can be satisfied (...) in our world if it is non-dynamical, and, if it can, what sort of thing in our world satisfies that concept. In particular, we focus on the question of whether that concept (if satisfied) is satisfied by something mind-dependent or something mind-independent. In other words, we ask, is temporal passage something that is at least partially in the mind, or is it entirely external to the mind? We find, contrary to what is often assumed by dynamists and non-dynamists alike, that the folk concept of temporal passage is satisfied in our world conditional on it being non-dynamical, and that the concept is satisfied by something mind-independent. This provides further ammunition for recent deflationary accounts of temporal passage that attempt to locate passage somewhere in our non-dynamical world. (shrink)

Recent research has begun treating the perennial philosophical question, “what makes a person the same over time?” as an empirical question. A long tradition in philosophy holds that psychological continuity and connectedness of memories are at the heart of personal identity. More recent experimental work, following Strohminger & Nichols (2014), has suggested that persistence of moral character, more than memories, is perceived as essential for personal identity. While there is a growing body of evidence supporting these findings, a critique by (...) Starmans & Bloom (2018) suggests that this research program conflates personal identity with mere similarity. To address this criticism, we explore how loss of someone’s morality or memories influence perceptions of identity change, and perceptions of moral duties towards the target of the change. We present participants with a classic ‘body switch’ thought experiment and after assessing perceptions of identity persistence, we present a moral dilemma, asking participants to imagine that one of the patients must die (Study 1) or be left alone in a care home for the rest of their life (Study 2). Our results highlight the importance of the continuity of moral character, suggesting lay intuitions are tracking (something like) personal identity, not just mere similarity. (shrink)

There is an old worry, which dates back to Mill but has analogs even in Sextus, that the very definition of ‘validity’ implies that all valid arguments are circular. This paper investigates how contemporary formal tools can ellucidate that old worry. Its main finding is the existence of a genuine puzzle: a difficult-to-avoid correspondence between the definitions of ‘valid argument’ and ‘premise circular argument’.

This paper presents a new solution to the problem of peer disagreement that distinguishes two principles of rational belief, here called probability and autonomy. When we discover that we disagree with peers, there is one sense in which we rationally ought to suspend belief, and another in which we rationally ought to retain our original belief. In the first sense, we aim to believe what is most probably true according to our total evidence, including testimony from peers and authorities. In (...) the second, we aim to base our beliefs only on objective evidence and argumentation, even if that lowers the probability of their being true. The first principle of rational belief tends to serve the short-term epistemic interests of individuals, while the second tends to serve the long-term epistemic interests of both individuals and groups. The best way to reconcile these principles in cases of peer disagreement is to associate them with two corresponding species of belief, here called perception and opinion. (shrink)

In two recent papers, Michael Della Rocca accuses Descartes of reasoning circularly in the Fourth Meditation. This alleged new circle is distinct from, and more vicious than, the traditional Cartesian Circle arising in the Third Meditation. We explain Della Rocca’s reasons for this accusation, showing that his argument is invalid.

Recent research has relied on trolley-type sacrificial moral dilemmas to study utilitarian versus nonutili- tarian modes of moral decision-making. This research has generated important insights into people’s attitudes toward instrumental harm—that is, the sacrifice of an individual to save a greater number. But this approach also has serious limitations. Most notably, it ignores the positive, altruistic core of utilitarianism, which is characterized by impartial concern for the well-being of everyone, whether near or far. Here, we develop, refine, and validate a (...) new scale—the Oxford Utilitarianism Scale—to dissociate individual differences in the ‘negative’ (permissive attitude toward instrumental harm) and ‘positive’ (impartial concern for the greater good) dimensions of utilitarian thinking as manifested in the general population. We show that these are two independent dimensions of proto-utilitarian tendencies in the lay population, each exhibiting a distinct psychological profile. Empathic concern, identification with the whole of humanity, and concern for future generations were positively associated with impartial beneficence but negatively associated with instrumental harm; and although instrumental harm was associated with subclinical psychopathy, impartial beneficence was associated with higher religiosity. Importantly, although these two dimensions were independent in the lay population, they were closely associated in a sample of moral philosophers. Acknowledging this dissociation between the instrumental harm and impartial beneficence components of utilitarian thinking in ordinary people can clarify existing debates about the nature of moral psychology and its relation to moral philosophy as well as generate fruitful avenues for further research. (shrink)

When you and I seriously argue over whether a man of seventy is old enough to count as an "old man", it seems that we are appealing neither to our own separate standards of oldness nor to a common standard that is already fixed in the language. Instead, it seems that both of us implicitly invoke an ideal, shared standard that has yet to be agreed upon: the place where we ought to draw the line. As with other normative standards, (...) it is hard to know whether such borderlines exist prior to our coming to agree on where they are. But epistemicists plausibly argue that they must exist whether we ever agree on them or not, as this provides the only logically acceptable response to the sorites paradox. This paper argues that such boundaries do typically exist as hypothetical ideals, but not as determinate features of the present actual world. There is in fact no general solution to the paradox, but attention to practice in resolving vague disagreements shows that its instances can be dealt with separately, as they arise, in many reasonable ways. (shrink)

In this chapter, we outline the interdisciplinary contributions that philosophy, psychology, and neuroscience have provided in the understanding of the self and identity, focusing on one specific line of burgeoning research: the importance of morality to perceptions of self and identity. Of course, this rather limited focus will exclude much of what psychologists and neuroscientists take to be important to the study of self and identity (that plethora of self-hyphenated terms seen in psychology and neuroscience: self-regulation, self-esteem, self-knowledge, self-concept, self-perception, (...) and more). We will likewise not engage with many canonical philosophical treatments of self and identity. But we will lay out a body of research that brings together classic themes in philosophy, psychology, and neuroscience to raise empirically tractable philosophical questions, and philosophically rigorous empirical questions about self and identity. More specifically, in section 4.2, we will review some recent research that has treated traditional philosophical questions about self and identity as empirical questions. Within this body of work, we will be primarily concerned with the finding that morality (more so than memory) is perceived to be at the core of self and identity. Then, in section 4.3, we raise and respond to a variety of questions and criticisms: first, about the operationalization of identity concepts in the empirical literature; second, about the generalizability of the moral self effect; third, about the direction of change; fourth, about connections with recent work in neuroscience; and fifth, about the target of evaluation. Finally, in section 4.4, we consider a variety of implications and applications of this work on the moral self. Throughout, we aim to highlight connections between classical themes in philosophy, psychology, and neuroscience, while also suggesting new directions for interdisciplinary collaboration. (shrink)

It has been hypothesized that our believing that, or its seeming to us as though, the world is in some way dynamical partially explains (and perhaps rationalizes) future-bias. Recent work has, in turn, found a correlation between future-bias and near-bias, suggesting that there is a common explanation for both. Call the claim that what partially explains our being both future- and near-biased is our believing/it seeming to us as though the world is dynamical, the dynamical explanation. We empirically test two (...) versions of the dynamical explanation. The first is the moving ego explanation—according to which it is our belief that the ego moves, or our phenomenology as of the ego moving, that jointly (partially) explains future- and near-bias. The second is the moving time explanation—according to which it is our belief that time robustly passes, or our phenomenology as of robust passage, which jointly (partially) explain future- and near-bias. We found no evidence in favour of either explanation. (shrink)

Gini coefficients, which measure gross inequalities rather than their unfair components, are often used as proxy measures of absolute or relative distributive injustice in Western societies. This presupposes that the fair inequalities in these societies are small and stable enough to be ignored. This article presents a model for a series of ideal, perfectly just societies, where comfortable lives are equally available to everyone, and calculates the Gini coefficients for each. According to this model, inequalities produced by age and other (...) demographic factors, together with reasonable choices under equal opportunity, can raise the Gini coefficients for perfectly just societies to levels at least as high as those of any current Western country, and can as easily account for differences in Gini coefficients between such societies or within one such society over time. If Gini coefficients at these levels are possible for ideal societies without distributive injustice, then they should not be used as proxy measures of distributive injustice in real societies. (shrink)

Why is science so rare and faith so common in human history? Traditional cultures persist because it is subjectively rational for each maturing child to defer to the unanimous beliefs of his elders, regardless of any personal doubts. Science is possible only when individuals promote new theories (which will probably be proven false) and forgo the epistemic advantages of accepting established views (which are more likely to be true). Hence, progressive science must rely upon the epistemic altruism of experimental thinkers, (...) while traditions of faith depend on the epistemic self-interest of their followers. (shrink)

This paper raises an underappreciated paradox for classical theism. Love seems to be an inherently biased and partial relation. Justice seems to require the opposite, detached impartiality (think of the attributes of the just judge). But if these are conceptual facts, then classical theism is guilty of ascribing inconsistent attributes to God: perfect love and perfect justice. I resolve this paradox in a manner that weighs in favor of the principle of divine simplicity.

Why are we conscious? What does consciousness enable us to do that cannot be done by zombies in the dark? This paper argues that introspective consciousness probably co-evolved as a "spandrel" along with our more useful ability to represent the mental states of other people. The first part of the paper defines and motivates a conception of consciousness as a kind of "double vision" – the perception of how things seem to us as well as what they are – along (...) lines recently explored by Peter Carruthers. The second part explains the basic socioepistemic function of consciousness and suggests an evolutionary pathway to this cognitive capacity that begins with predators and prey. The third part discusses the relevance of these considerations to the traditional problem of other minds. (shrink)

There are things of which it is true to say that there are no such things. How can we resolve this paradox? Panayot Butchvarov argues that there are objects of reference that are not also entities, where the former must merely be thinkable but the latter must be indefinitely re-identifiable. This paper argues that fictional and many other unreal objects are indeed indefinitely re-identifiable, so they must be counted as existing things on Butchvarov's theory. The paradox is best resolved by (...) distinguishing among domains of existence: Sherlock Holmes exists in the unrestricted domain of objects and in the fictional domain created by Conan Doyle, but not in the domain of the real world. Thus to exist and to be real are different things; all objects exist in some domain, but only real objects really exist. (shrink)

Solipsism can be refuted along fairly traditional, internalist lines, by means of a second-order induction. We are justified in believing in other minds, because other people tell us that they have minds, and we have good inductive reason to believe that whatever certain others say is likely to be true. This simple argument is sound, the author argues, even though we are in no prior position to believe that other thinking people exist as such, or that the sounds they make (...) have any meaning. The mere phenomenal surfaces of others' statements form sufficient grounds for the induction that the argument requires. (shrink)

This article provides an intuitive semantic account of a new logic for comparisons (CL), in which atomic statements are assigned both a classical truth-value and a “how much” value or extension in the range [0, 1]. The truth-value of each comparison is determined by the extensions of its component sentences; the truth-value of each atomic depends on whether its extension matches a separate standard for its predicate; everything else is computed classically. CL is less radical than Casari’s comparative logics, in (...) that it does not allow for the formation of comparative statements out of truth-functional molecules. It is argued that CL provides a better analysis of predicate vagueness than classical logic, fuzzy logic or supervaluation theory. (shrink)