It will be shown that the Peres–Mermin square admits value-definite noncontextual hidden-variable models if the observables associated with the operators can be measured only sequentially but not simultaneously. Namely, sequential measurements allow for noncontextual models in which hidden states update between consecutive measurements. Two recent experiments realizing the Peres–Mermin square by sequential measurements will also be analyzed along with other hidden-variable models accounting for these experiments.

The common cause principle says that every correlation is either due to a direct causal effect linking the correlated entities or is brought about by a third factor, a so-called common cause. The principle is of central importance in the philosophy of science, especially in causal explanation, causal modeling and in the foundations of quantum physics. Written for philosophers of science, physicists and statisticians, this book contributes to the debate over the validity of the common cause principle, by proving results (...) that bring to the surface the nature of explanation by common causes. It provides a technical and mathematically rigorous examination of the notion of common cause, providing an analysis not only in terms of classical probability measure spaces, which is typical in the available literature, but in quantum probability theory as well. The authors provide numerous open problems to further the debate and encourage future research in this field. (shrink)

A partition $\{C_i\}_{i\in I}$ of a Boolean algebra $\cS$ in a probability measure space $(\cS,p)$ is called a Reichenbachian common cause system for the correlated pair $A,B$ of events in $\cS$ if any two elements in the partition behave like a Reichenbachian common cause and its complement, the cardinality of the index set $I$ is called the size of the common cause system. It is shown that given any correlation in $(\cS,p)$, and given any finite size $n>2$, the probability space (...) $(\cS,p)$ can be embedded into a larger probability space in such a manner that the larger space contains a Reichenbachian common cause system of size $n$ for the correlation. It also is shown that every totally ordered subset in the partially ordered set of all partitions of \cS$ contains only one Reichenbachian common cause system. Some open problems concerning Reichenbachian common cause systems are formulated. (shrink)

This essay has two main claims about EPR’s Reality Criterion. First, we claim that the application of the Reality Criterion makes an essential difference between the EPR argument and Einstein’s later arguments against quantum mechanics. We show that while the EPR argument, making use of the Reality Criterion, does derive that certain interpretations of quantum mechanics are incomplete, Einstein’s later arguments, making no use of the Reality Criterion, do not prove incompleteness, but rather point to the inadequacy of the Copenhagen (...) interpretation. We take this fact as an indication that the Reality Criterion is a crucial, indispensable component of the incompleteness argument(s). The second claim is more substantive. We argue that the Reality Criterion is a special case of the Common Cause Principle. Finally, we relate this proposal to Tim Maudlin’s recent assertion that the Reality Criterion is an analytic truth. (shrink)

A condition is formulated in terms of the probabilities of two pairs of correlated events in a classical probability space which is necessary for the two correlations to have a single (Reichenbachian) common-cause and it is shown that there exists pairs of correlated events probabilities of which violate the necessary condition. It is concluded that different correlations do not in general have a common common-cause. It is also shown that this conclusion remains valid even if one weakens slightly Reichenbach's definition (...) of common-cause. The significance of the difference between common-causes and common common-causes is emphasized from the perspective of Reichenbach's Common Cause Principle. (shrink)

A partition $\{C_i\}_{i\in I}$ of a Boolean algebra Ω in a probability measure space (Ω, p) is called a Reichenbachian common cause system for the correlation between a pair A,B of events in Ω if any two elements in the partition behave like a Reichenbachian common cause and its complement; the cardinality of the index set I is called the size of the common cause system. It is shown that given any non-strict correlation in (Ω, p), and given any finite (...) natural number n > 2, the probability space (Ω,p) can be embedded into a larger probability space in such a manner that the larger space contains a Reichenbachian common cause system of size n for the correlation. (shrink)

I will argue that Kochen-Specker arguments do not provide an algebraic proof for quantum contextuality since, for the argument to be effective, operators must be uniquely associated with measur...

I will argue that the Peres-Mermin square does not necessarily rule out a value-definite (deterministic) noncontextual hidden variable model if the operators are not given a physical interpretation satisfying the following two requirements: (i) each operator is uniquely realized by a single physical measurement; (ii) commuting operators are realized by simultaneous measurements. To underpin this claim, I will construct three hidden variable models for three different physical realizations of the Peres-Mermin square: one violating (i), another violating (ii), and a third (...) one violating both (i) and (ii). (shrink)

Standard derivations of the Bell inequalities assume a common common cause system that is a common screener-off for all correlations and some additional assumptions concerning locality and no-conspiracy. In a recent paper (Grasshoff et al., 2005) Bell inequalities have been derived via separate common causes assuming perfect correlations between the events. In the paper it will be shown that the assumptions of this separate-common-cause-type derivation of the Bell inequalities in the case of perfect correlations can be reduced to the assumptions (...) of common-common-cause-system-type derivation. However, in the case of non-perfect correlations a non-reducible separate-common-cause-type derivation of some Bell-like inequalities can be given. The violation of these Bell-like inequalities proves Szabó's (2000) conjecture concerning the non-existence of a local, non-conspiratorial, separate-common-cause-model for a delta δ-neighborhood of perfect EPR correlations. (shrink)

Bell inequalities, understood as constraints between classical conditional probabilities, can be derived from a set of assumptions representing a common causal explanation of classical correlations. A similar derivation, however, is not known for Bell inequalities in algebraic quantum field theories establishing constraints for the expectation of specific linear combinations of projections in a quantum state. In the paper we address the question as to whether a ‘common causal justification’ of these non-classical Bell inequalities is possible. We will show that although (...) the classical notion of common causal explanation can readily be generalized for the non-classical case, the Bell inequalities used in quantum theories cannot be derived from these non-classical common causes. Just the opposite is true: for a set of correlations there can be given a non-classical common causal explanation even if they violate the Bell inequalities. This shows that the range of common causal explanations in the non-classical case is wider than that restricted by the Bell inequalities. (shrink)

The Borel–Kolmogorov Paradox is typically taken to highlight a tension between our intuition that certain conditional probabilities with respect to probability zero conditioning events are well defined and the mathematical definition of conditional probability by Bayes’ formula, which loses its meaning when the conditioning event has probability zero. We argue in this paper that the theory of conditional expectations is the proper mathematical device to conditionalize and that this theory allows conditionalization with respect to probability zero events. The conditional probabilities (...) on probability zero events in the Borel–Kolmogorov Paradox also can be calculated using conditional expectations. The alleged clash arising from the fact that one obtains different values for the conditional probabilities on probability zero events depending on what conditional expectation one uses to calculate them is resolved by showing that the different conditional probabilities obtained using different conditional expectations cannot be interpreted as calculating in different parametrizations of the conditional probabilities of the same event with respect to the same conditioning conditions. We conclude that there is no clash between the correct intuition about what the conditional probabilities with respect to probability zero events are and the technically proper concept of conditionalization via conditional expectations—the Borel–Kolmogorov Paradox is just a pseudo-paradox. (shrink)

Standard derivations of the Bell inequalities assume a common-commoncause-system that is a common screener-off for all correlations and some additional assumptions concerning locality and no-conspiracy. In a recent paper Graßhoff et al., "The British Journal for the Philosophy of Science", 56, 663–680 ) Bell inequalities have been derived via separate common causes assuming perfect correlations between the events. In the paper it will be shown that the assumptions of this separate-common-cause-type derivation of the Bell inequalities in the case of perfect (...) correlations can be reduced to the assumptions of a common-common-cause-system-type derivation. However, in the case of non-perfect correlations a non-reducible separate-common-cause-type derivation of some Bell-like inequalities can be given. The violation of these Bell-like inequalities proves Szabo's ) conjecture concerning the non-existence of a local, non-conspiratorial, separate-common-cause-model for a δ-neighborhood of perfect EPR correlations. (shrink)

In the paper it will be shown that Reichenbach’s Weak Common Cause Principle is not valid in algebraic quantum field theory with locally finite degrees of freedom in general. Namely, for any pair of projections A, B supported in spacelike separated double cones ${\mathcal{O}}_{a}$ and ${\mathcal{O}}_{b}$ , respectively, a correlating state can be given for which there is no nontrivial common cause (system) located in the union of the backward light cones of ${\mathcal{O}}_{a}$ and ${\mathcal{O}}_{b}$ and commuting with the both (...) A and B. Since noncommuting common cause solutions are presented in these states the abandonment of commutativity can modulate this result: noncommutative Common Cause Principles might survive in these models. (shrink)

The aim of this paper is to give a sharp definition of Bell's notion of local causality. To this end, first we unfold a framework, called local physical theory, integrating probabilistic and spatiotemporal concepts. Formulating local causality within this framework and classifying local physical theories by whether they obey local primitive causality---a property rendering the dynamics of the theory causal, we then investigate what is needed for a local physical theory, with or without local primitive causality, to be locally causal. (...) Finally, comparing Bell's local causality with the Common Cause Principles and relating both to the Bell inequalities we find a nice parallelism: Bell inequalities cannot be derived neither from local causality nor from a common cause unless the local physical theory is classical or the common cause is commuting, respectively. (shrink)

This paper is the philosopher-friendly version of our more technical work. It aims to give a clear-cut definition of Bell's notion of local causality. Having provided a framework, called local physical theory, which integrates probabilistic and spatiotemporal concepts, we formulate the notion of local causality and relate it to other locality and causality concepts. Then we compare Bell's local causality with Reichenbach's Common Cause Principle and relate both to the Bell inequalities. We find a nice parallelism: both local causality and (...) the Common Cause Principle are more general notions than captured by the Bell inequalities. Namely, Bell inequalities cannot be derived neither from local causality nor from a common cause unless the local physical theory is classical or the common cause is commuting, respectively. (shrink)

​This book summarizes the results of research the authors have pursued in the past years on the problem of implementing Bell's notion of local causality in local physical theories and relating it to other important concepts and principles in the foundations of physics such as the Common Cause Principle, Bell's inequalities, the EPR scenario, and various other locality and causality concepts. The book is intended for philosophers of science with an interest in the formal background of sciences, philosophers of physics (...) and physicists working in foundation of physics. (shrink)

It is a well known fact that a common common causal explanation of the EPR scenario which consists in providing a local, non-conspiratorial common common cause system for a set of EPR correlations is excluded by various Bell inequalities. But what if we replace the assumption of a common common cause system by the requirement that each correlation of the set has a local, non-conspiratorial separate common cause system? In the paper we show that this move does not yield a (...) solution by providing a general recipe how to derive any Bell(δ) inequality—that is an inequality differing from some Bell inequality in a term of order of δ—from the assumption that an appropriate set of almost perfect anticorrelations has a separate common causal explanation. (shrink)

This paper is a further consideration of Hemmo and Shenker’s ideas about the proper conceptual characterization of macrostates in statistical mechanics. We provide two formulations of how macrostates come about as elements of certain partitions of the system’s phase space imposed on by the interaction between the system and an observer, and we show that these two formulations are mathematically equivalent. We also reflect on conceptual issues regarding the relationship of macrostates to distinguishability, thermodynamic regularity, observer dependence, and the general (...) phenomenon of measurement. (shrink)

The aim of the paper is to relate Bell’s notion of local causality to the Causal Markov Condition. To this end, first a framework, called local physical theory, will be introduced integrating spatiotemporal and probabilistic entities and the notions of local causality and Markovity will be defined. Then, illustrated in a simple stochastic model, it will be shown how a discrete local physical theory transforms into a Bayesian network and how the Causal Markov Condition arises as a special case of (...) Bell’s local causality and Markovity. (shrink)

This paper aims to implement Bell’s notion of local causality into a framework, called local physical theory, which is general enough to integrate both probabilistic and spatiotemporal concepts and also classical and quantum theories. Bell’s original idea of local causality will then arise as the classical case of our definition. First, we investigate what is needed for a local physical theory to be locally causal. Then we compare local causality with Reichenbach’s common cause principle and relate both to the Bell (...) inequalities. We find a nice parallelism: both local causality and the common cause principle are more general notions than captured by the Bell inequalities. Namely, Bell inequalities cannot be derived neither from local causality nor from a common cause unless the local physical theory is classical or the common cause is commuting, respectively. (shrink)

In the paper the relation between the standard probabilistic characterization of the common cause and Bell's notion of local causality will be investigated. It will be shown that the probabilistic common cause follows from local causality if one accepts, as Bell did, two assumptions concerning the common cause: first, the common cause is localized in the intersection of the past of the correlating events; second, it provides a complete specification of the `beables' of this intersection. However, neither assumptions are a (...) priori requirements. In the paper the logical role of these assumptions will be studied and it will be shown that only the second assumption is necessary for the derivation of the probabilistic common cause from local causality. (shrink)

In the paper we compare three principles accounting for correlations, namely Reichenbach's Common Cause Principle, Bell's Local Causality Principle, and Einstein's Reality Criterion and relate them to the Bell inequalities. We show that there are two routes connecting the principles to the Bell inequalities. In case of Reichenbach's Common Cause Principle and Bell's Local Causality Principle one assumes a non-conspiratorial joint common cause for a set of correlations. In case of Einstein's Reality Criterion one assumes strongly non-conspiratorial separate common causes (...) for a set of perfect correlations. Strongly non-conspiratorial separate common causes for perfect correlations, however, form a non-conspiratorial joint common cause. Hence the two routes leading the Bell inequalities meet. (shrink)

Our approach aims at accounting for causal claims in terms of how the physical states of the underlying dynamical system evolve with time. Causal claims assert connections between two sets of physicals states—their truth depends on whether the two sets in question are genuinely connected by time evolution such that physical states from one set evolve with time into the states of the other set. We demonstrate the virtues of our approach by showing how it is able to account for (...) typical causes, causally relevant factors, being ‘the’ cause, and cases of overdetermination and causation by absences. (shrink)

It is shown that, given any finite set of pairs of random events in a Boolean algebra which are correlated with respect to a fixed probability measure on the algebra, the algebra can be extended in such a way that the extension contains events that can be regarded as common causes of the correlations in the sense of Reichenbach's definition of common cause. It is shown, further, that, given any quantum probability space and any set of commuting events in it (...) which are correlated with respect to a fixed quantum state, the quantum probability space can be extended in such a way that the extension contains common causes of all the selected correlations, where common cause is again taken in the sense of Reichenbach's definition. It is argued that these results very strongly restrict the possible ways of disproving Reichenbach's Common Cause Principle. (shrink)

Anything other than paraphrasing the well-known Heraclitean aphorism would not be more appropriate to portray the crux of the contribution of the three philosophers of the Budapest School, Gábor Hofer-Szabó, Miklós Rédei and Lázló E. Szabó, in the ongoing discussion of the principle of the common cause . Indeed, ‘common causes love to hide’ and for that reason critics and aspirant falsifiers of PCC find correlations which, at a first level of analysis, might lack a common cause explanation. But (...) as the authors argue such correlations do not amount to disconfirming evidence for the principle, since PCC does not specify where to search for a common cause of a correlation; it just states that there is one. PCC is neither falsifiable, nor verifiable; it is a metaphysical doctrine that can only be assessed for its plausibility in the light of theories of empirical science. This idea fosters the investigation of the existence of common causes of correlations in two fundamental physical t .. (shrink)

A one-page editorial including one-sentence summaries of papers authored by Carsten Held, Elise Crull, Johanna Wolff, Elay Shech, Richard Dawid, and Gábor Hofer-Szabó.

This special issue includes papers authored by Carsten Held, Elise Crull, Johanna Wolff, Elay Shech, Richard Dawid, and Gábor Hofer-Szabó.

Based on the existence of polysemy (e.g., lunch can refer to both food and events), it is argued that central tenets of externalist semantics and Fodorian concept atomism, an externalist theory on which words lack semantic structure, are unsound. We evaluate the premise that these arguments rely on—that polysemous words have separate, finer‐grained senses. We survey the evidence across psychology and linguistics and argue that it shows that polysemy does not exist, at least not in this “sense”. The upshot is (...) that if polysemy does not exist, it cannot pose a problem for atomism or externalism. (shrink)

In this short study, I attempt to reconstruct the main conceptual components of Edmund Husserl’s concept of death following the leading clue of his late transcendental phenomenological methodology. First, I summarise his thoughts on death, from the point of view of “the natural attitude”, as an event in the world. Then, I try and explore the manifold senses of the limit phenomenon of death as a multidimensional transcendental phenomenological problem in all of its intersubjective-world constitutive, personal-primordial, and metaphysical-constructive layers of (...) meanings, respectively. By doing so, I also hope that the path we travel can serve the reader as an opportunity for a personal and reflective confrontation with death. (shrink)

We explain the general significance of integer-based descriptors for natural shapes and show that the evolution of two such descriptors, called mechanical descriptors (the number _N_(_t_) of static balance points and the Morse–Smale graph associated with the scalar distance function measured from the center of mass) appear to capture (unlike classical geophysical shape descriptors) one of our most fundamental intuitions about natural abrasion: shapes get monotonically _simplified_ in this process. Thus mechanical descriptors help to establish a correlation between subjective and (...) objective descriptors of perceived objects. (shrink)

Plato claimed that the regular solids are the building blocks of all matter. His views, commonly referred to as the geometric atomistic model, had enormous impact on human thought despite the fact that four of the five Platonic solids can not fill space without gaps. In this paper we quantify these gaps, showing that the errors in Plato’s estimates were quite small. We also develop a mean field approximation to convex honeycombs using a generalized version of Plato’s idea. This approximation (...) not only admits to view convex mosaics in$$d=3$$d=3dimensions as a continuum but we also find that it is quite accurate, showing that Plato’s geometric intuition may have been remarkable. (shrink)

Play is not only a kind of activity, but also a set of attitudes. We may join a card game in a casino without assuming a play attitude; conversely we may transform a seemingly tedious action, such as a walk to the store, into a pleasant experience of spontaneous movements by adopting an attitude of play. Attitudes of Play is a comprehensive study of the persistent human tendency to bring a cheerful and good-humoured outlook to any kind of situation, including (...) the serious and the mundane. Gabor Csepregi offers a phenomenological description of forms of playfulness, showing how, time and again, our attitudes of play redefine and shape diverse activities and experiences – from teaching, healing, or worshipping to political conflict or walking down the street. With play attitudes, we exercise our freedom to colour these scenes or give them an altogether new form, evoking in us more refined sentiments and more acute perceptions. This book seeks to distinguish play activities from attitudes of play, showing that the latter hold value not merely for their educational or other instrumental benefits but also, and perhaps most importantly, for the overall fulfillment and well-being they offer in all stages of human existence. (shrink)

Which works and tenets of early modern natural law reached East-Central Europe, and how? How was it received, what influence did it have? And how did theorists and users of natural law in East- Central Europe enrich the pan-European discourse? This volume is pioneering in two ways; it draws the east of the Empire and its borderlands into the study of natural law, and it adds natural law to the practical discourse of this region. Drawing on a large amount of (...) previously neglected printed or handwritten sources, the authors highlight the impact that Grotius, Pufendorf, Heineccius and others exerted on the teaching of politics and moral philosophy as well as on policies regarding public law, codification praxis, or religious toleration. Contributors are: Péter Balázs, Ivo Cerman, Karin Friedrich, Gábor Gángó, Anna Grześkowiak-Krwawicz, Knud Haakonssen, Steffen Huber, Borbála Lovas, Martin P. Schennach, and József Simon. (shrink)