In this paper, it is argued that the prima facie conflict between special relativity and the quantum-mechanical collapse postulate is only apparent, and that the seemingly incompatible accounts of entangled systems undergoing collapse yielded by different reference frames can be regarded as no more than differing accounts of the same processes and events. Attention to the transformation properties of quantum-mechanical states undergoing unitary, non-collapse evolution points the way to a treatment of collapse evolution consistent with (...) the demands of relativity. r 2002 Elsevier Science Ltd. All rights reserved. (shrink)

Everett proposed resolving the quantum measurement problem by dropping the nonlinear collapse dynamics from quantum mechanics and taking what is left as a complete physical theory. If one takes such a proposal seriously, then the question becomes how much of the predictive and explanatory power of the standard theory can one recover without the collapse postulate and without adding anything else. Quantum mechanics without the collapse postulate has several suggestive properties, which we will consider in (...) some detail. While these properties are not enough to make it acceptable given the usual standards for a satisfactory physical theory, one might want to exploit these properties to cook up a satisfactory no-collapse formulation of quantum mechanics. In considering how this might work, we will see why any no-collapse theory must generally fail to satisfy at least one of two plausible-sounding conditions. (shrink)

Because of the measurement problem, the standard theory of quantum mechanics is at best incomplete and at worst logically inconsistent. Everett suggested that the measurement problem could be resolved by taking the linear dynamics to be a complete and accurate description of the time-evolution of every physical system. The purpose of this dissertation is to see what happens when one takes Everett's proposal seriously. This dissertation includes a discussion of the standard theory of quantum mechanics and its origins, the measurement (...) problem, Everett's relative-state formulation, the many-worlds interpretation, Albert's bare theory and its suggestive properties, and Albert and Loewer's single-mind and many-minds theories. I will show how one might construct a theory that exploits the bare theory's suggestive properties without encountering its empirical problems. (shrink)

In this paper, it is argued that the prima facie conflict between special relativity and the quantum-mechanical collapse postulate is only apparent, and that the seemingly incompatible accounts of entangled systems undergoing collapse yielded by different reference frames can be regarded as no more than differing accounts of the same processes and events. Attention to the transformation properties of quantum-mechanical states undergoing unitary, non-collapse evolution points the way to a treatment of collapse evolution consistent with (...) the demands of relativity. (shrink)

Proposed derivations of the Born rule for Everettian theory are controversial. I argue that they are unnecessary but may provide justification for a simplified version of the Principal Principle. It’s also unnecessary to replace Everett’s idea that a subject splits in measurement contexts with the idea that subjects have linear histories which partition Many worlds? Everett, quantum theory, and reality, Oxford University Press, Oxford, pp 181–205, 2010; Wallace in The emergent multiverse, Oxford University Press, Oxford, 2012, Chapter 7; Wilson in (...) Br J Philos Sci 64:709–737, 2013; The nature of contingency: quantum physics as modal realism, Oxford University Press, Oxford, forthcoming). Linear histories were introduced to provide a concept of pre-measurement uncertainty and I explain why pre-measurement uncertainty for splitting subjects is after all coherent, though not necessary because Everett’s original fission interpretation of branching can arguably be rendered coherent without it, via reference to Vaidman, Tappenden, Sebens and Carroll and McQueen and Vaidman. A deterministic and probabilistic quantum mechanics can be made intelligible by replacing the standard collapse postulate with a no-collapse postulate which identifies objective probability with relative branch weight, supplemented by the simplified Principal Principle and some revisionary metaphysics. (shrink)

It is emphasized that the collapse postulate of standard quantum theory can violate conservation of energy-momentum and there is no indication from where the energy-momentum comes or to where it goes. Likewise, in the Continuous Spontaneous Localization (CSL) dynamical collapse model, particles gain energy on average. In CSL, the usual Schrödinger dynamics is altered so that a randomly fluctuating classical field interacts with quantized particles to cause wavefunction collapse. In this paper it is shown how to (...) define energy for the classical field so that the average value of the energy of the field plus the quantum system is conserved for the ensemble of collapsing wavefunctions. While conservation of just the first moment of energy is, of course, much less than complete conservation of energy, this does support the idea that the field could provide the conservation law balance when events occur. (shrink)

The conjunction of Schrodinger dynamics and the usual way of thinking about the conditions under which quantum systems exhibit determinate values implies that measurements don't have outcomes. The orthodox fix to this quantum measurement problem is von Neumann's postulate of measurement collapse, which suspends Schrodinger dynamics in measurement contexts. Contending that the fundamental dynamical law of quantum theory breaks down every time we test the theory empirically, the collapse postulate is unsatisfactory. Recently philosophers and physicists have (...) proposed a less violent solution to the measurement problem. Their modal interpretations of quantum mechanics advocate unusual ways of thinking about the situations under which quantum systems exhibit determinate observable values, semantics which reconcile determinate measurement outcomes with universal Schrodinger dynamics. Thus modal interpretations hold out hope that quantum theory is complete and exceptionless. ;This dissertation tempers that hope. I consider the modal approach to the neglected problem of state preparation. A promising modal account exploits standard quantum transition probabilities. But, I claim, modal interpretations must subject these transition probabilities to a consistency constraint which they can be shown to violate. Non-standard transition probabilities might avoid this inconsistency, but they would also introduce novel dynamics, and so undo the modal triumph of taking Schrodinger dynamics to be complete and universal. Next I consider Albert and Loewer's assault on modal accounts of "error-prone" measurements. I argue that the Albert-Loewer problem is more general than Albert, Loewer, or their critics appreciate, and that the Araki-Yanase theorem implies the existence of a class of observables whose error-free measurements succumb to the Albert-Loewer problem. I review modal responses to Albert and Loewer which appeal to the palliative effects of a decohering environment and find them incomplete. Finally, based on the physicist Anthony Leggett's work with SQUIDs, I present a system concerning which the empirical commitments of modal interpretations contradict those of the quantum statistical algorithm, minimally interpreted. I conclude that these modal difficulties can be resolved only by taking the quantum formalism to be incomplete. (shrink)

There has been an upsurge of interest lately in developing Wigner’s hypothesis that conscious observation causes collapse by exploring dynamical collapse models in which some purportedly quantifiable aspect of consciousness resist superposition. Kremnizer–Ranchin, Chalmers–McQueen and Okon–Sebastián have explored the idea that collapse may be associated with a numerical measure of consciousness. More recently, Chalmers–McQueen have argued that any single measure is inadequate because it will allow superpositions of distinct states of equal consciousness measure to persist. They suggest (...) a satisfactory model needs to associate collapse with a set of measures quantifying aspects of consciousness, such as the “Q-shapes” defined by Tononi et al. in their “integrated information theory” of consciousness. I argue here that Chalmers–McQueen’s argument against associating a single measure with collapse requires a precise symmetry between brain states associated with different experiences and thus does not apply to the only case where we have strong intuitions, namely human observers. In defence of Chalmers–McQueen’s stance, it might be argued that idealized artificial information processing networks could display such symmetries. However, I argue that the most natural form of any theory that postulates a map from network states to mind states is one that assigns identical mind states to isomorphic network states. This suggests that, if such a map exists, no familiar components of mind states, such as viewing different colours, or experiencing pleasure or pain, are likely to be related by symmetries. (shrink)

The projection postulate, which prescribes “collapse of the state vector” upon measurement, is not an essential part of quantum mechanics. Rather it is only an optional discarding of certain branches of the state vector that are expected to be irrelevant for the purpose at hand. However, its use is hazardous, and there are examples of repeated measurements for which the conventional application of the projection postulate leads to incorrect results.

The collapse of quantum states is analyzed in terms of a breakdown into two generic phases: Phase I, in which the field of potentialities that the quantum state represents undergoes a discontinuous and unpredictable change into one of the base states which corresponds to the measurement performed, and phase II, in which a transition from the level of potentialities to the level of actualities takes place. Phase I is discussed in relation to a comment about collapse, made by (...) Dirac in conversation with the author, “Nature makes a choice.” An analysis of phase II leads to the suggestion that it occurs only through and as an act of experience. This postulate is shown to elucidate basic questions regarding the interpretation of quantum mechanics, such as the elusive demarcation line between the classical and quantum domains, and the controversy of the ontological vs. epistemological interpretation of quantum mechanics. (shrink)

Highlights: -/- • -/- Proposes forward-looking approach to studying climate collapse risks. • -/- Suggests diminishing returns on climate adaptation as a collapse mechanism. • -/- Suggests strategies for sustainable adaptation pathways in face of climate change. • -/- Illustrates analysis with examples of small island states and global food security. -/- Abstract: -/- This article proposes a forward-looking approach to studying societal collapse risks related to climate change. Such an approach should indicate how to study emerging (...) collapse risks and suggest strategies for adapting to them. Our approach is based on three postulates that facilitate a forward-looking approach: (1) collapse, if it occurred, would be a lengthy process rather than an abrupt event; (2) significant collapse risks already exist in some places; and (3) diminishing returns on adaptation to intensifying climate impacts are a key driver of collapse risks. The first two postulates suggests that collapse risks can be studied in process, while the third points to strategies for adaptation pathways that avoid unsustainable diminishing returns. Applying diminishing returns to climate change adaptation, rather than sociopolitical complexity or resource extraction, is also a novel theoretical contribution to collapse literature. [Open access]. (shrink)

A common way of characterizing Boltzmann’s explanation of thermodynamics in term of statistical mechanics is with reference to three ingredients: the dynamics, the past hypothesis, and the statistical postulate. In this paper I focus on the statistical postulate, and I have three aims. First, I wish to argue that regarding the statistical postulate as a probability postulate may be too strong: a postulate about typicality would be enough. Second, I wish to show that there is (...) no need to postulate anything, for the typicality postulate can be suitably derived from the dynamics. Finally, I discuss how the attempts to give preference to certain stochastic quantum theories (such as the spontaneous collapse theory) over deterministic alternatives on the basis that they do not need the statistical postulate fail. (shrink)

A common way of characterizing Boltzmann’s explanation of thermodynamics in term of statistical mechanics is with reference to three ingredients: the dynamics, the past hypothesis, and the statistical postulate. In this paper I focus on the statistical postulate, and I have three aims. First, I wish to argue that regarding the statistical postulate as a probability postulate may be too strong: a postulate about typicality would be enough. Second, I wish to show that there is (...) no need to postulate anything, for the typicality postulate can be suitably derived from the dynamics. Finally, I discuss how the attempts to give preference to certain stochastic quantum theories (such as the spontaneous collapse theory) over deterministic alternatives on the basis that they do not need the statistical postulate fail. (shrink)

We prove a uniqueness theorem showing that, subject to certain natural constraints, all 'no collapse' interpretations of quantum mechanics can be uniquely characterized and reduced to the choice of a particular preferred observable as determine (definite, sharp). We show how certain versions of the modal interpretation, Bohm's 'causal' interpretation, Bohr's complementarity interpretation, and the orthodox (Dirac-von Neumann) interpretation without the projection postulate can be recovered from the theorem. Bohr's complementarity and Einstein's realism appear as two quite different proposals (...) for selecting the preferred determinate observable--either settled pragmatically by what we choose to observe, or fixed once and for all, as the Einsteinian realist would require, in which case the preferred observable is a 'beable' in Bell's sense, as in Bohm's interpretation (where the preferred observable is position in configuration space). (shrink)

Ever since the early days of quantum mechanics it has been suggested that consciousness could be linked to the collapse of the wave function. However, no detailed account of such an interplay is usually provided. In this paper we present an objective collapse model where the collapse operator depends on integrated information, which has been argued to measure consciousness. By doing so, we construct an empirically adequate scheme in which superpositions of conscious states are dynamically suppressed. Unlike (...) other proposals in which “consciousness causes the collapse of the wave function,” our model is fully consistent with a materialistic view of the world and does not require the postulation of entities suspicious of laying outside of the quantum realm. (shrink)

Modal interpretations of quantum mechanics admit two kinds of state: physical states, which specify the values of observables on a system, and theoretical states, which specify a probability distribution over possible physical states. They appear to use this distinction to deny the projection postulate, claiming that collapse corresponds only to a change from discussing the theoretical state to discussing the physical state. I argue that modal interpretations should adopt a projection postulate at the level of the theoretical (...) state. However, other features of modal interpretations might render the projection postulate immune from the usual objections. (shrink)

I briefly sketch Bohm's causal interpretation (BCI) and its solution to the measurement problem. Crucial to BCI's no-collapse account of both ideal and non-ideal measurement is the existence of particles in addition to wavefunctions. The particles in their role as the producers of the observable experimental outcomes render practical considerations, such as what observables can be reasonably measured or how to get rid of interference terms in non-ideal measurements, secondary to BCI's account of measurement. I then explain why it (...) is not easy for BCI to justify its statistical postulate. To successfully justify the postulate would be to solve the distribution problem. Two proposed deterministic solutions to this problem are only briefly set out and not discussed in detail. BCI can solve the measurement problem whether or not the distribution problem is solved. However, if the distribution problem is not solved, BCI cannot be shown to be empirically adequate. (shrink)

Quantum mechanics without the collapse postulate, the bare theory, was proposed by Albert (1992) as a way of understanding Everett's relative-state formulation of quantum mechanics. The basic idea is to try to account for an observer's beliefs by appealing to a type of illusion predicted by the bare theory. This paper responds to some recent objections to the bare theory by providing a more detailed description of the sense in which it can and the sense in which it (...) cannot account for our experience. (shrink)

Criteria of adequacy for scientific representation of the phenomena pertain to accuracy and truth. But that representation is selective and may require distortion even in the selected parameters; this point is intimately connected with the fact that representation is intentional, and its adequacy relative to its particular purpose. Since observation and measurement are perspectival and the appearances to be saved are perspectival measurement outcomes, the question whether this “saving” is an explanatory relation provides a new focus for the realist/antirealist debate. (...) The Born rule and von Neumann's “collapse” postulate in quantum mechanics provide a telling case for this question in recent physics. (shrink)

In order to judge whether a theory is empirically adequate one must have epistemic access to reliable records of past measurement results that can be compared against the predictions of the theory. Some formulations of quantum mechanics fail to satisfy this condition. The standard theory without the collapse postulate is an example. Bell's reading of Everett's relative-state formulation is another. Furthermore, there are formulations of quantum mechanics that only satisfy this condition for a special class of observers, formulations (...) whose empirical adequacy could only be judged by an observer who records her measurement results in a special way. Bohm's theory is an example. It is possible to formulate hidden-variable theories that do not suffer from such a restriction, but these encounter other problems. (shrink)

Spontaneous collapse theories of quantum mechanics turn the usual Schrödinger equation into a stochastic dynamical law. In particular, in this paper, I will focus on the GRW theory. Two philosophical issues that can be raised about GRW concern (i) the ontology of the theory, in particular the nature of the wave function and its role within the theory, and (ii) the interpretation of the objective probabilities involved in the dynamics of the theory. During the last years, it has been (...) claimed that we can take advantage of dispositional properties in order to develop an ontology for GRW theory, and also in order to ground the objective probabilities which are postulated by it. However, in this paper, I will argue that the dispositional interpretations which have been discussed in the literature so far are either flawed or – at best – incomplete. If we want to endorse a dispositional interpretation of GRW theory we thus need an extended account that specifies the precise nature of those properties and which makes also clear how they can correctly ground all the probabilities postulated by the theory. Thus, after having introduced several different kinds of probabilistic dispositions, I will try to fill the gap in the literature by proposing a novel and complete dispositional account of GRW, based on what I call spontaneous weighted multi-track propensities. I claim that such an account can satisfy both of our desiderata. (shrink)

Although the present paper looks upon the formal apparatus of quantum mechanics as a calculus of correlations, it goes beyond a purely operationalist interpretation. Having established the consistency of the correlations with the existence of their correlata, and having justified the distinction between a domain in which outcome-indicating events occur and a domain whose properties only exist if their existence is indicated by such events, it explains the difference between the two domains as essentially the difference between the manifested world (...) and its manifestation. A single, intrinsically undifferentiated Being manifests the macroworld by entering into reflexive spatial relations. This atemporal process implies a new kind of causality and sheds new light on the mysterious nonlocality of quantum mechanics. Unlike other realist interpretations, which proceed from an evolving-states formulation, the present interpretation proceeds from Feynman’s formulation of the theory, and it introduces a new interpretive principle, replacing the collapse postulate and the eigenvalue–eigenstate link of evolving-states formulations. Applied to alternatives involving distinctions between regions of space, this principle implies that the spatiotemporal differentiation of the physical world is incomplete. Applied to alternatives involving distinctions between things, it warrants the claim that, intrinsically, all fundamental particles are identical in the strong sense of numerical identical. They are the aforementioned intrinsically undifferentiated Being, which manifests the macroworld by entering into reflexive spatial relations. (shrink)

The bare theory is the standard von Neumann·Dirac formulation of quantum mechanics without the collapse postulate but with the eigenvalueeigenstate link. Albert (1992, 1i6-125) presented the bare theory as one way of understanding EverettRi7;s relative-state interpretation. At first glance, it looks as if the bare theory cannot possibly account for our experience. After all, at the end of a measurement an observer will typically be in a superposition of having recorded mutually incompatible results, which on the standard interpretation (...) of states (the interpretation provided by the eigenvalue-eigenstate.. (shrink)

There seems to be a growing consensus that any interpretation of quantum mechanics other than an instrumentalist interpretation will have to abandon the requirement of Lorentz invariance, at least at the fundamental level, preserving at best Lorentz invariance of phenomena. In particular, it is often said that the collapse postulate is incompatible with the demands of relativity. It is the purpose of this paper to argue that such a conclusion is premature, and to defend the view that a (...) covariant account of collapse can be given according to which the state histories yielded by different reference frames are the Lorentz transforms of each other. Objections that have been raised to such a view are considered. (shrink)

The author attempts to investigate connections and interdependencies between periphery countries and the globalisation process, including the attitude of these countries to unification blocs, such as the European integration project. The basic research tool used in this work is a systemic analysis, as well as the core-periphery method, derived from social sciences. Its fundamental hypothesis is that the decline of the liberal architecture of the globe may translate into the periphery’s tendency to abandon real convergence in favour of the fragmentary (...) imitation of supranational bodies, potentially leading to intensified disintegration tendencies within phenomena, such as the consolidation of Europe. In the past, the powerless core of the community only contemplated the imitative Europeanisation of marginal territories. Today, however – because the idea to construct a homogeneous polity has collapsed – postulates of “multi-speed” integration can lead to the reconstruction of the historical division into the core and periphery of the old continent. (shrink)

Beyond Peaceful Coexistence: The Emergence of Space, Time and Quantum brings together leading academics in mathematics and physics to address going beyond the 'peaceful coexistence' of space-time descriptions (local and continuous ones) and quantum events (discrete and non-commutative ones). Formidable challenges waiting beyond the Standard Model require a new semantic consistency within the theories in order to build new ways of understanding, working and relating to them. The original A. Shimony meaning of the peaceful coexistence (the collapse postulate (...) and non-locality) appear to be just the tip of the iceberg in relation to more serious fundamental issues across physics as a whole. Chapters in this book present perspectives on emergent, discrete, geometrodynamic and topological approaches, as well as a new interpretative spectrum of quantum theories after Copenhagen, discrete time theories, time-less approaches and 'super-fluid' pictures of space-time. As well as stimulating further research among established theoretical physicists, the book can also be used in courses on the philosophy and mathematics of theoretical physics. (shrink)

The measurement problem concerns an apparent conflict between the two fundamental principles of quantum mechanics, namely the Schrödinger equation and the measurement postulate. These principles describe inconsistent behavior for quantum systems in so-called "measurement contexts." Many theorists have thought that the measurement problem can only be resolved by proposing a mechanistic explanation of (genuine or apparent) wavefunction collapse that avoids explicit reference to "measurement." However, I argue here that the measurement problem dissolves if we accept Humeanism about laws (...) of nature. On a Humean metaphysics, there is no conflict between the two principles, nor is there any inherent problem with the concept of "measurement" figuring into the account of collapse. (shrink)

Christopher Fuchs has recently offered a provocative version of quantum mechanical realism, which is based on the suggestion that quantum probabilities merit a subjective interpretation. His proposal, however, has been charged with inconsistency by Amit Hagar (2003), who argues that interpreting quantum probabilities subjectively is inconsistent with the realist claims Fuchs wants to maintain for the quantum system and the dimensionality of the Hilbert space that accompanies it. In this paper I first outline the fundamentals of Fuchs's approach and then (...) take up the task of rebutting Hagar's charge by demonstrating the internal coherence of Fuchs's realism. (shrink)

In 1957, Feyerabend delivered a paper titled ‘On the Quantum-Theory of Measurement’ at the Colston Research Symposium in Bristol to sketch a completion of von Neumann's measurement scheme without collapse, using only unitary quantum dynamics and well-motivated statistical assumptions about macroscopic quantum systems. Feyerabend's paper has been recognised as an early contribution to quantum measurement, anticipating certain aspects of decoherence. Our paper reassesses the physical and philosophical content of Feyerabend's contribution, detailing the technical steps as well as its overall (...) philosophical motivations and consequences. Summarising our results, Feyerabend interpreted collapse as a positivist assumption in quantum mechanics leading to a strict distinction between the uninterpreted formalism of unitary evolution in quantum mechanics and the classically interpreted observational language describing post-measurement outcomes. Thus Feyerabend took the no-collapse completion of the von Neumann measurement scheme to show the dispensability of the positivist assumption, leading the way to a realistic interpretation of quantum theory. We note, however, that there are substantial problems with his account of measurement that bring into question its viability as a legitimate foil to the orthodox view. We further argue that his dissatisfaction with the von Neumann measurement scheme is indicative of early views on theoretical pluralism. (shrink)

This paper presents a new Symmetrical Interpretation (SI) of relativistic quantum mechanics which postulates: quantum mechanics is a theory about complete experiments, not particles; a complete experiment is maximally described by a complex transition amplitude density; and this transition amplitude density never collapses. This SI is compared to the Copenhagen Interpretation (CI) for the analysis of Einstein’s bubble experiment. This SI makes several experimentally testable predictions that differ from the CI, solves one part of the measurement problem, resolves some inconsistencies (...) of the CI, and gives intuitive explanations of some previously mysterious quantum effects. (shrink)

Spontaneous collapse theories provide a promising solution to the measurement problem. But they also introduce a number of problems of their own concerning dimensionality, vagueness, and locality. In response to these problems, advocates of collapse theories have proposed various accounts of the primitive ontology of collapse theories—postulated underlying entities governed by the collapse theory and underwriting our observations. The most prominent of these are a mass density distribution over three-dimensional space, and a set of discrete “flash” (...) events at space-time points. My argument here is that these primitive ontologies are redundant, in the sense that the structures exhibited by the primitive ontologies that allow them to solve the problems facing spontaneous collapse theories are also present in the wave function. But redundancy is not nonexistence; indeed, the fact that the relevant structures are already there in the wave function shows that the mass density ontology and the flash ontology exist whether they are explicitly postulated or not. By the same token, there is no need to decide between a wave function ontology, a mass density ontology and a flash ontology. (shrink)

The postulate that a stalled/collapsed replication fork will be generated when the replication complex encounters a UV‐induced lesion in the template for leading‐strand DNA synthesis is based on the model of semi‐discontinuous DNA replication. A review of existing data indicates that the semi‐discontinuous DNA replication model is supported by data from in vitro studies, while the discontinuous DNA replication model is supported by in vivo studies in Escherichia coli. Until the question of whether DNA replicates discontinuously in one or (...) both strands is clearly resolved, any model building based on either one of the two DNA replication models should be treated with caution. BioEssays 27:633–636, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

Aristotle explains existence through postulating essences that are intrinsic and percep- tion independent. I argue that his theory is more plausible than Hume’s and Russell’s theories of existence. Russell modifies Hume’s theory because he wants to allow for the existence of mathematical objects. However, Russell’s theory facilitates a problematic collapse of ontology into epistemology, which has become a feature of much analytic philosophy. This collapse obscures the nature of truth. Aristotle is to be praised for starting with a (...) clear account of ordinary objects rather than immediately reifying mathematical objects. He thus allows us to have a coherent account of existence and truth, and to easily resist collapsing ontology into epistemology. (shrink)

Aristotle explains existence through postulating essences that are intrinsic and perception independent. I argue that his theory is more plausible than Hume’s and Russell’s theories of existence. Russell modifies Hume’s theory because he wants to allow for the existence of mathematical objects. However, Russell’s theory facilitates a problematic collapse of ontology into epistemology, which has become a feature of much analytic philosophy. This collapse obscures the nature of truth. Aristotle is to be praised for starting with a clear (...) account of ordinary objects rather than immediately reifying mathematical objects. He thus allows us to have a coherent account of existence and truth, and to easily resist collapsing ontology into epistemology. (shrink)

In "Finance Capital" (1910), Rudolf Hilferding put forward a theory of capitalist development and imperialism that exerted a powerful influence on Marxist thinking throughout the Twentieth Century. After the First World War, however, Hilferding radically altered that theory. Instead of global capitalist development fueling rivalries among the capitalist states that would likely lead to war, he postulated that mutual economic interests, buttressed by close political and cultural affinities, would be more likely to promote cooperative relations among the western powers which (...) would seek to maintain international peace. Hilferding believed that the “unbridled competition of individual sovereign states” was gradually giving way to a “community of interests.” He suggested that international treaties, the expansion of democracy, and the construction of the League of Nations, would reduce the importance of national sovereignty and would pave the way for peace and socialism. The Second World War and the Cold War seemed to relegate Hilferding’s ideas to the dustbin of history, but the collapse of the communist world and the “triumph of capitalism” have, once again, radically altered the international terrain. This paper argues that important elements of Hilferding’s theory apply to the present capitalist order in which, though imperialism remains alive and well, war among the major powers seems improbable. (shrink)

Bohmian mechanics and the Ghirardi-Rimini-Weber theory provide opposite resolutions of the quantum measurement problem: the former postulates additional variables (the particle positions) besides the wave function, whereas the latter implements spontaneous collapses of the wave function by a nonlinear and stochastic modification of Schrödinger's equation. Still, both theories, when understood appropriately, share the following structure: They are ultimately not about wave functions but about 'matter' moving in space, represented by either particle trajectories, fields on space-time, or a discrete set of (...) space-time points. The role of the wave function then is to govern the motion of the matter. (shrink)

We defend the many-worlds interpretation of quantum mechanics against the objection that it cannot explain why measurement outcomes are predicted by the Born probability rule. We understand quantum probabilities in terms of an observer's self-location probabilities. We formulate a probability postulate for the MWI: the probability of self-location in a world with a given set of outcomes is the absolute square of that world's amplitude. We provide a proof of this postulate, which assumes the quantum formalism and two (...) principles concerning symmetry and locality. We also show how a structurally similar proof of the Born rule is available for collapse theories. We conclude by comparing our account to the recent account offered by Sebens and Carroll. (shrink)

In this paper we attempt to physically interpret the Modal Kochen–Specker theorem. In order to do so, we analyze the features of the possible properties of quantum systems arising from the elements in an orthomodular lattice and distinguish the use of “possibility” in the classical and quantum formalisms. Taking into account the modal and many worlds non-collapse interpretation of the projection postulate, we discuss how the MKS theorem rules the constraints to actualization, and thus, the relation between actual (...) and possible realms. (shrink)

In this work we attempt to confront the orthodox widespread claim, present in the philosophical and foundational debates about Quantum Mechanics (QM), that ‘superpositions are never actually observed in the lab’. In order to do so, we begin by providing a critical analysis of the famous measurement problem which, we will argue, was originated as a consequence of the strict application of the empirical-positivist requirements to subsume the quantum formalism under their specific understanding of a physical ‘theory’. In particular, the (...) ad hoc introduction of the projection postulate (or measurement rule) can be understood as the necessity of imposing a naive empiricist standpoint which presupposes that observations are self evident givens of “common sense” experience independent of metaphysical (or conceptual) presuppositions yet necessarily represented in binary terms. We then turn our attention to two “non-collapse” interpretations of QM—namely, modal and many worlds—which even though deny that the “collapse” is a real physical process retain anyhow the projection rule as a necessary axiom of the theory itself. In contraposition, following Einstein’s claim that “it is only the theory which decides what can be observed”, we propose a return to the realist representational understanding of physical theories in which ‘observation’ is not a “self evident” given of experience but something that can be only understood in the context of a theoretical (formal-conceptual) scheme. It is from this standpoint that we discuss a new non-classical conceptual representation which allows us to understand quantum phenomena in an intuitive (anschaulicht) manner. Leaving behind the projection postulate, we discuss the general physical conditions for measuring and observing quantum superpositions in the lab. (shrink)

The Quantum Measurement Problem is arguably one of the most debated issues in the philosophy of Quantum Mechanics, since it represents not only a technical difficulty for the standard formulation of the theory, but also a source of interpretational disputes concerning the meaning of the quantum postulates. Another conundrum intimately connected with the QMP is the Wigner friend paradox, a thought experiment underlining the incoherence between the two dynamical laws governing the behavior of quantum systems, i.e the Schrödinger equation and (...) the projection rule. Thus, every alternative interpretation aiming to be considered a sound formulation of QM must provide an explanation to these puzzles associated with quantum measurements. It is the aim of the present essay to discuss them in the context of Relational Quantum Mechanics. In fact, it is shown here how this interpretative framework dissolves the QMP. More precisely, two variants of this issue are considered: on the one hand, I focus on the “the problem of outcomes” contained in Maudlin (1995)—in which the projection postulate is not mentioned—on the other hand, I take into account Rovelli’s reformulation of this problem proposed in Rovelli (2022), where the tension between the Schrödinger equation and the stochastic nature of the collapse rule is explicitly considered. Moreover, the relational explanation to the Wigner’s friend paradox is reviewed, taking also into account some interesting objections contra Rovelli’s theory contained in Laudisa (2019). I contend that answering these critical remarks leads to an improvement of our understanding of RQM. Finally, a possible objection against the relational solution to the QMP is presented and addressed. (shrink)

A drastic resolution of the quantum paradoxes is proposed, combining (I) von Neumann's postulate that collapse of the state vector is due to the act of observation, and (II) my reinterpretation of von Neumann's quantal irreversibility as an equivalence between wave retardation and entropy increase, both being “factlike” rather than “lawlike” (Mehlberg). This entails a coupling of the two de jure symmetries between (I) retarded and (II) advanced waves, and between Aristotle's information as (I) learning and (II) willing (...) awareness. Symmetric acceptance of cognizance as a source of retarted waves, and of will as a sink of advanced waves, is submitted as a central “paradox” of the Copernican or Einsteinian sort, out of which new light is shed upon previously known paradoxes, such as the EPR paradox, Schrödinger's cat, and Wigner's friend. Parapsychology is thus found to creep into the picture. (shrink)

We look into the ontology of quantum theory as distinct from that of the classical theory in the sciences. Theories carry with them their own ontology while the metaphysics may remain the same in the background. We follow a broadly Kantian tradition, distinguishing between the noumenal and phenomenal realities where the former is independent of our perception while the latter is assembled from the former by means of fragmentary bits of interpretation. Theories do not tell us how the noumenal world (...) is constituted but are conceptual constructs applying to models generated in the phenomenal world within limited contexts. -/- The ontology of quantum theory principally rests on the view that entities in the world are pervasively correlated with one another not by means of probabilities as in the case of the classical theory, but by means of probability amplitudes involving finely tuned phases characterising the oscillatory behaviour of quantum mechanical states. -/- The amplitude-dependent correlations (quantum entanglement) exist over and above the classical ones expressed in terms of probabilities. While the classical correlations are essentially local in nature, quantum correlations are shared globally in the process of environment-induced decoherence. The decoherence is an effectively random process that removes local correlations in the course of global sharing of entanglement—the removal being especially manifest in the case of systems that appear as classical ones. It is this aspect of the decoherence process that makes the so-called measurement postulate (one relating to wave function collapse) cohere with the rest of the principles of quantum theory where the latter implies a Schrodinger type time evolution of quantum mechanical systems. -/- The mathematical basis of the quantum correlations consists of the description of pure states of a system in terms of vectors in a linear vector space (a mixed state appears as an admixture of pure states with some probability distribution associated with it) and, in addition, the description of (pure) states of composite systems as vectors in the product space arising from the component sub-systems. -/- The crucial aspect of the decoherence process, of significance in the context of the apparent incompatibility of the measurement postulate with the unitary Schrodinger evolution, relates to the fact that it is almost instantaneous in the case of a classical object (one that is nevertheless amenable to a quantum description). Indeed, the decoherence time is, in all likelihood, of the order of the Planck scale, being driven by field fluctuations in the Planck regime. This points to factors of an unknown nature determining the finest details of the decoherence process since Planck scale physics remains an obscure terrain. -/- In other words, quantum theory is, to all intents and purposes, in the need of a radical revision, in keeping with the fact that all theories are defeasible and need revision as our domains of experience expand and get realigned in a complex manner. The context within which quantum theory (and quantum field theory too) is defined is set precisely by the Planck scale, across which a novel theoretical framework is likely to emerge. However, as in the case of theory revisions in general, that emerging theory will stand in an asymmetric relation of incommensurability with the present-day quantum theory, where the concepts of the latter will be comprehensible in terms of those of the former, but the converse will not hold. (shrink)

Over the last decade, attention has crawled from out of the shadows into the philosophical limelight with several important books and widely read articles. Carolyn Dicey Jennings has been a key player in the attention revolution, actively publishing in the area and promoting awareness. This book was much anticipated by insiders and does not disappoint. It is in no way redundant with respect to other recent monographs, covering both a different range of material and developing novel positions throughout. The book (...) might have been called The Attending Self, since Jennings defines attention as mental prioritization controlled by the self. This invocation of the self is among her central innovations, and may prove to be the main source of controversy. I will highlight points of contention here, but want to emphasize at the outset that the book is essential reading for anyone interested in attention. Jennings also contributes to a range of other debates, which will help a broader audience appreciate the importance this topic.After a brief introduction, Jennings provides “a philosophical landscape” of attention (chap. 2), tracing the concept through history. This is an invaluable achievement that will be welcomed by both newcomers and veterans. Jennings exhibits enormous breadth, covering areas that contemporary philosophers of mind tend to neglect: medieval philosophy, Buddhist thought, and phenomenology, to name a few. We also get perspectives on attention from core figures in the Western canon, such as Descartes, Locke, and Kant, as well as thinkers who gave the topic a more political inflection: Mary Wollstonecraft and W. E. B. DuBois. Jennings surveys contemporary literature as well, locating recent work in these older lineages. Some authors get more treatment later in the book (e.g., William James and Wayne Wu). Overall, Jennings provides the best overview of this history I have seen. She proves that attention is not a new topic, but one with deep roots and one that can inform current debates; Jennings draws on these roots throughout. I would love to see a companion piece surveying scientific theories, including “gain control” and “biased competition,” which get little airtime in the book. Some recent philosophical theories are under-explored as well, including Chris Mole’s concept of cognitive unison (Jennings discusses other aspects of his view), Carlos Montemayor and Harry Haladjian’s exploration of attention’s diversity (we get a touch of this), and my own proposal that attention is a gateway to working memory (not mentioned here). That said, no extant survey is more complete.Chapter 3 begins with the empirical claim that attention is regulated by slow brainwaves, and then takes up two issues. The first is mental causation. Endorsing moderate emergentism, Jennings argues that slow brain waves are causally efficacious even though they are not reducible to lower-level processes. (The metaphysics and neuroscience are presented accessibly, aided by three appendixes.) Second, Jennings argues that these slow brain waves indicate that attention is controlled by the self. As someone who was never moved by the mental causation problem—I don’t think overdetermination threatens efficacy—I would have welcomed more development of this second issue. For one thing, in linking attention to subjective control, Jennings eschews the idea that there can be purely “bottom-up” attention driven by stimulus features alone. This goes against the orthodoxy in attention science, and makes it hard for her to accommodate phenomena such as “pop-out,” or the commonsense idea that attention can be “captured” by a sudden flash or loud sound. For another thing, I wanted to hear more on why Jennings relates slow brain waves to the self. Does this include the slow waves that occur during deep sleep? Is there even such a thing as the self? Is there one self or many? How do slow brain waves reflect our interests, projects, values, self-conceptions, autobiographical narratives, or social identities? Does the social self invoked by Wollstonecraft and DuBois gain a foothold here? The whole chapter campaigns against metaphysical reductionism, but arrives at a perspective on the self that will strike some readers as highly reductive.In the fourth chapter, Jennings sheds further light on her conjecture that attention involves the self by advancing the thesis that attention endows sensory information with meaning. On the face of it, this may sound implausible. Object recognition, reading, and many other meaning-involving processes can take place outside of attention and outside of consciousness. But Jennings has a richer notion of “meaning” in mind. She develops the idea of “subject unity,” which is imposition of structure on perception that reflects the interests of the perceiving subject. This, she claims, is what brings perception into the space of reasons. Along the way, she has interesting observations about binding, feature integration, and demonstrative reference. The material is highly original, and Jennings’s postulation of interest-based perceptual organization is compelling. At the same time, one might wonder whether interests are really relegated to the ambit of attentional control. Consider the cocktail party effect, wherein one’s own name captures attention. This implies a preattentive filter that reflects our interests. Emotionally charged words, facial expressions, and dangerous objects also work this way, and social biases can operate preattentively as well. If these reflect our interests, then meaning may arise outside attention.Jennings’s fifth chapter explores the relationship between attention and consciousness. Some authors have argued that attention is necessary and sufficient for consciousness. Jennings focuses primarily on the necessity claim. She does not systematically review the empirical literature here, but she addresses some of the key findings, and effectively rebuts studies that allege to find consciousness outside attention. She does not rest her case there, however. Instead, she identifies a new class of examples that purport to establish the possibility of consciousness without attention. Her central example she calls “conscious entrainment,” which is what we experience when engaged in habitual or skilled activities. Other possible examples touched on in the chapter include hypervigilance in individuals with attention deficit hyperactivity disorder (ADHD), passive movie watching, dreaming, and “attentional neglect.” These states all involve intense focus, Jennings admits, but not attention. To some readers this may sound contradictory. Isn’t focus a kind of attention? Don’t these states of absorption involve stimulus selection and enhancement of relevant features, suppression of distractors, and other hallmarks of attention? Jennings says none of this is tantamount to attention. Recall that she thinks attention is controlled by the self. In these cases, we are invited to imagine that the self takes a passive role: control is either ceded to the world (movie watching) or to previously mastered routines (skills and habits). Thus, Jennings’s claim that there is no attention in these cases hangs on her contentious thesis that attention requires a controlling self. One might also push back by arguing that, in some of Jennings’s allegedly selfless examples, the self remains involved. Skilled activities and hypervigilance, for example, can reflect personal interests.Skills and hypervigilance get more airtime in chapter 6. There, Jennings turns to questions of responsibility—a neglected topic in attention research. The chapter begins with a manslaughter trial in which the teenage plaintiff was given a light sentence because the judge evidently believed that the teen’s ADHD compromised his ability to control his actions. The example may be a bit triggering for people who have a personal relationship with this diagnosis, but, putting that aside, Jennings uses it to introduce the important concept of attention-based control. With reduced control, Jennings argues, comes reduced responsibility. I am inclined to see ADHD as involving dysregulation of attention (difficulty disengaging and dividing attention, for example) rather than diminished attention, but that can still be characterized as an issue with control of attention; therefore ADHD still illustrates Jennings’s point that there is a link between responsibility and control of attention. This, it turns out, is only half of her story. Having argued for this link, one might expect Jennings to follow Wayne Wu, who contends that attention is necessary for action, and hence for responsibility. She does not. Instead, she says argues that responsibility can also arise in cases of “strategic automaticity.” This brings us back to skills. When skills are deployed, action is governed by learned pairings between stimuli and responses. The choice to exercise a skill requires attention, so attention is needed for being a responsible agent, but once a skill kicks in, attention is no longer required, and one can be held responsible for actions performed skillfully—thus attention is not required for responsibility tout court. Jennings addresses an opposing view (defended by Wu, Ellen Fridland, and Barbara Montero), according to which skills involve “automatic attention” rather than no attention. Jennings worries that this move will collapse the distinction between attention and other kinds of selection and filtering that occur throughout the nervous system, including the retina. She says that the attentional interpretation of skilled action is at odds with the lack of top-down reweighing of sensory inputs, regulated by lateral frontal cortex. These objections to automatic attention warrant response. My own view is that attention involves broadcasting to working memory, so retinal filtering is ruled out. Jennings’s insistence on top-down reweighing will not move those who believe attention can be purely bottom-up. For all that, I side with Jennings in wanting to allow for responsibility without attentional control. I think we can be responsible for implicit biases, for example. I also think attentional control is insufficient for responsibility, as when we act under duress.Jennings offers fresh perspective on the nature of attention, and its role in meaningful perception, consciousness, action, and responsibility. Each chapter can be read separately, but they hang together well, and each reflects her thesis that attention is essentially linked to the self. Though I am skeptical of that strong claim, we would do well to follow Jennings in regarding attention as interest-laden interface between mind and world. I look forward to a sequel in which attention is related to richer conceptions of identity, and where the political consequences of this link are actively explored. Meanwhile, one can hardly fault Jennings for covering too little. She tackles a remarkable range of topics, from metaphysics to ethics. Her arguments throughout demand response, repay careful study, and propel the field forward. (shrink)

Friedrich Hölderlin argued that consciousness requires division and unity. Consciousness emerges through the fundamental distancing of the subject from its surroundings, without which the subject-object distinction would collapse and both objectivity and consciousness would be lost. Nevertheless, insofar as conscious knowledge is unitary, division demands a ground for unity. Hölderlin calls this ground ‘Being [Seyn].’ However, once Being is affirmed, the question of how it is accessed arises. Hölderlin’s scholars disagreed on this issue. This disagreement gave rise to two (...) camps: those who deny that Hölderlin accepts the idea of direct access to Being and believe that he proves Being through an act of reflection (Henrich); and those who argue that for Hölderlin, ‘Being’ is directly accessed. Those who hold the latter position can be further divided into those who conceive of this direct access as knowledge (Frank) and those who argue that this access does not have a cognoscitive character, but rather an aesthetic one (Waibel). This article considers these positions and shows that the direct apprehension of ‘Being’ is part of Hölderlin’s argument aimed at solving a fundamental problem; an argument that differs both from the postulate of access to Being as knowledge of transcendence and from the affirmation of a purely aesthetic mode of access. (shrink)

This work examines whether the environmentally-induced decoherence approach in quantum mechanics brings us any closer to solving the measurement problem, and whether it contributes to the elimination of subjectivism in quantum theory. A distinction is made between ,collapse, and ,decoherence,, so that an explanation for decoherence does not imply an explanation for collapse. After an overview of the measurement problem and of the open-systems paradigm, we argue that taking a partial trace is equivalent to applying the projection (...) class='Hi'>postulate. A criticism of Zurek's decoherence approach to measurements is also made, based on the restriction that he must impose on the interaction between apparatus and environment. We then analyze the element of subjectivity involved in establishing the boundary between system and environment, and criticize the incorporation of Everett's branching of memory records into the decoherence research program. Sticking to this program, we end by sketching a proposal for ‘environmentally-induced collapse’. (shrink)

We propose a technical reformulation of the measurement problem of quantum mechanics, which is based on the postulate that the final state of a measurement is classical; this accords with experimental practice as well as with Bohr’s views. Unlike the usual formulation (in which the post-measurement state is a unit vector in Hilbert space), our version actually opens the possibility of admitting a purely technical solution within the confines of conventional quantum theory (as opposed to solutions that either modify (...) this theory, or introduce unusual and controversial interpretative rules and/or ontologies). To that effect, we recall a remarkable phenomenon in the theory of Schrödinger operators (discovered in 1981 by Jona-Lasinio, Martinelli, and Scoppola), according to which the ground state of a symmetric double-well Hamiltonian (which is paradigmatically of Schrödinger’s Cat type) becomes exponentially sensitive to tiny perturbations of the potential as ħ→0. We show that this instability emerges also from the textbook wkb approximation, extend it to time-dependent perturbations, and study the dynamical transition from the ground state of the double well to the perturbed ground state (in which the cat is typically either dead or alive, depending on the details of the perturbation). Numerical simulations show that adiabatically arising perturbations may (quite literally) cause the collapse of the wave-function in the classical limit. Thus, at least in the context of a simple mathematical model, we combine the technical and conceptual virtues of decoherence (which fails to solve the measurement problem but launches the key idea that perturbations may come from the environment) with those of dynamical collapse models à la grw (which do solve the measurement problem but are ad hoc), without sharing their drawbacks: single measurement outcomes are obtained (instead of merely diagonal reduced density matrices), and no modification of quantum mechanics is needed. (shrink)

Consciousness and quantum mechanics are two great mysteries of our time--and recently scholars have postulated a deeper connection between them. Exploring this possible connection can be fruitful: an analysis of the conscious mind and psychophysical connection can be indispensable in understanding quantum mechanics and solving the notorious measurement problem, and there is also likely some kind of intimate connection between quantum mechanics--the most fundamental theory of the physical world--and our efforts to explain, naturalistically, the phenomenon of consciousness. The sixteen newly (...) written chapters in this volume are divided into three sections: Consciousness and the Wave Function Collapse, Consciousness in Quantum Theories, and Quantum Approaches to Consciousness. This is the first volume to provide a comprehensive review and thorough analysis of intriguing conjectures about the connection between consciousness and quantum mechanics. Written by leading experts in physics, philosophy, and cognitive science, Consciousness and Quantum Mechanics will be of value to students and researchers working on the foundations of quantum mechanics and the philosophy of mind. (shrink)

We propose a technical reformulation of the measurement problem of quantum mechanics, which is based on the postulate that the final state of a measurement is classical; this accords with experimental practice as well as with Bohr’s views. Unlike the usual formulation (in which the post-measurement state is a unit vector in Hilbert space), our version actually opens the possibility of admitting a purely technical solution within the confines of conventional quantum theory (as opposed to solutions that either modify (...) this theory, or introduce unusual and controversial interpretative rules and/or ontologies).To that effect, we recall a remarkable phenomenon in the theory of Schrödinger operators (discovered in 1981 by Jona-Lasinio, Martinelli, and Scoppola), according to which the ground state of a symmetric double-well Hamiltonian (which is paradigmatically of Schrödinger’s Cat type) becomes exponentially sensitive to tiny perturbations of the potential as ħ→0. We show that this instability emerges also from the textbook wkb approximation, extend it to time-dependent perturbations, and study the dynamical transition from the ground state of the double well to the perturbed ground state (in which the cat is typically either dead or alive, depending on the details of the perturbation).Numerical simulations show that adiabatically arising perturbations may (quite literally) cause the collapse of the wave-function in the classical limit. Thus, at least in the context of a simple mathematical model, we combine the technical and conceptual virtues of decoherence (which fails to solve the measurement problem but launches the key idea that perturbations may come from the environment) with those of dynamical collapse models à la grw (which do solve the measurement problem but are ad hoc), without sharing their drawbacks: single measurement outcomes are obtained (instead of merely diagonal reduced density matrices), and no modification of quantum mechanics is needed. (shrink)

The existence of non-local correlations between outcomes of measurements in quantum entangled systems strongly suggests that we are dealing with some form of causation here. An assessment of this conjecture in the context of the collapse interpretation of quantum mechanics is the primary goal of this paper. Following the counterfactual approach to causation, I argue that the details of the underlying causal mechanism which could explain the non-local correlations in entangled states strongly depend on the adopted semantics for counterfactuals. (...) Several relativistically-invariant interpretations of spatiotemporal counterfactual conditionals are discussed, and the corresponding causal stories describing interactions between parts of an entangled system are evaluated. It is observed that the most controversial feature of the postulated causal connections is not so much their non-local character as a peculiar type of circularity that affects them. (shrink)

The Copenhagen interpretation, which informs the textbook presentation of quantum mechanics, depends fundamentally on the notion of ontological wave-particle duality and a viewpoint called “complementarity.” In this paper, Bohr's own interpretation is traced in detail and is shown to be fundamentally different from and even opposed to the Copenhagen interpretation in virtually all its particulars. In particular, Bohr's interpretation avoids the ad hoc postulate of wave function ‘collapse' that is central to the Copenhagen interpretation. The strengths and weakness (...) of both interpretations are summarized. ‡I thank Edward Mackinnon, Henry Folse, and Greg Anderson for valuable comments on the penultimate draft. The final responsibility for the paper rests with the author. †To contact the author, please write to: Bhaktivedanta Institute, 2334 Stuart Street, Berkeley, CA; e-mail: [email protected]. I have been unable to achieve a sharp formulation of Bohr's principle of complementarity despite much effort I have expended on it. (Einstein 1949, 674) While imagining that I understand the position of Einstein, as regards the EPR correlations, I have very little understanding of his principal opponent, Bohr. (Bell 1987, 155) Niels Bohr brain-washed a generation of physicists into believing that the problem had been solved fifty years ago. (Gell-Mann 1979, 29) Every sentence I say must be understood not as an affirmation, but as a question. (Niels Bohr, quoted in Jammer 1966, 175) Bohr's interpretation has never been fully clarified. It needs an interpretation itself, and only that will be its defense. (Weizsäcker 1971, 25). (shrink)