This article explains why Bohr does not need to discuss the projection postulate or the "problem of measurement". Beginning with a thumbnail sketch of Bohr 's general views, it is argued that Bohr interprets the state function as giving a statistical summary of experimental outcomes. Against the objection that Bohr was too much a microrealist to endorse such an instrumentalist statistical interpretation it is suggested that he rejected the issue of microrealism as not well formed. It is shown (...) that on his statistical interpretation Bohr does not need the projection postulate or face the usual problem of measurement. (shrink)

The projection postulate is the source of a long standing controversy in the interpretation of the axiomatic foundations of quantum mechanics. In a sense which is made precise in chapter II the projection postulate is a mathematical theorem easily derivable within the mathematical framework of the theory. This theorem receives a clear and straightforward interpretation if Luders' rule is given only statistical significance. Under the assumption that an interpretation of quantum mechanics has to provide an account (...) of the process of measurement as a change on the state of individual systems, however, additional interpretive assumptions are needed in order to arrive at a satisfactory interpretation of Luders' rule. ;I show in chapter III that there are serious problems with the usual interpretation by making explicit in a quantum logical framework the concept of individual state and minimal disturbance implicit in this view. In chapter IV I show that it is possible to formulate a natural interpretation of Luders' rule as a description of 'dispersion free' state transformations within a semantic framework that takes states of individual systems to be represented by Boolean ultrafilters , as opposed to the usual approach that takes individual states to be represented by lattice ultrafilters. This lay the ground for the clarification of several interpretive issues in the foundations of quantum mechanics. It is shown that Luders' rule can be justified as a description of individual state transformations without the need of imposing additional assumptions. The derivation of Luders' rule within the semantic framework of B-states shows an important connection between interpretation that take individual state to be 'relative' to experimental situations and the statistical structure of the theory. (shrink)

It is widely held that quantum mechanics is the first scientific theory to present scientifically internal, fundamental difficulties for a realistic interpretation (in the philosophical sense). The standard (Copenhagen) interpretation of the quantum theory is often described as the inevitable instrumentalistic response. It is the purpose of the present article to argue that quantum theory doesnot present fundamental new problems to a realistic interpretation. The formalism of quantum theory has the same states—it will be argued—as the formalisms of older physical (...) theories and is capable of the same kinds of philosophical interpretation. This result is reached via an analysis of what it means to give a realistic interpretation to a theory. The main point of difference between quantum mechanics and other theories—as far as the possibilities of interpretation are concerned—is the special treatment given tomeasurement by the “projection postulate.” But it is possible to do without this postulate. Moreover, rejection of the projection postulate does not, in spite of what is often maintained in the literature, automatically lead to the many-worlds interpretation of quantum mechanics. A realistic interpretation is possible in which only the reality ofone (our) world is recognized. It is argued that the Copenhagen interpretation as expounded by Bohr is not in conflict with the here proposed realistic interpretation of quantum theory. (shrink)

If we take the state function of quantum mechanics to describe belief states, arguments by Stairs and Friedman-Putnam show that the projection postulate may be justified as a kind of minimal change. But if the state function takes on a physical interpretation, it provides no more than what I call a fortuitous approximation of physical measurement processes, that is, an unsystematic form of approximation which should not be taken to correspond to some one univocal "measurement process" in nature. (...) This fact suggests that the projection postulate does not provide a proper locus for interpretive investigation. Readers will also find section 3's analysis of fortuitous approximations of independent interest and presented without the perils of quantum mechanics. (shrink)

Previous work has shown that the problem of measurement in quantum mechanics is not correctly seen as one of understanding some allegedly univocal process of measurement in nature which corresponds to the projection postulate. The present paper introduces a new perspective by showing that how we are to understand the nature of the change of quantum mechanical state on measurement depends very sensitively on the interpretation of the state function, and by showing how attention to this dependence can (...) greatly sharpen the problems and relations between them. In particular, the problems take a form resembling their traditional formulation only on an inexact value interpretation, according to which the state function attributes inexact values of quantities to systems. On other interpretations we can apply (with various drawbacks) the subensemble idea, according to which a discontinuous change of quantum mechanical description results on measurement simply because we need a new state function to describe a new object. (shrink)

The purpose of this paper is to solve a serious problem for the projection postulate involving the time-energy uncertainty relation. The problem was recently raised by Teller, who believes that the problem is insoluble and, consequently, that the projection postulate should no longer be regarded as a serious focus for interpretive investigation.

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)

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.

I show that the quantum state ω can be interpreted as defining a probability measure on a subalgebra of the algebra of projection operators that is not fixed (as in classical statistical mechanics) but changes with ω and appropriate boundary conditions, hence with the dynamics of the theory. This subalgebra, while not embeddable into a Boolean algebra, will always admit two-valued homomorphisms, which correspond to the different possible ways in which a set of “determinate” quantities (selected by ω and (...) the boundary conditions) can have values. The probabilities defined by ω (via the Born rule) are probabilities over these two-valued homomorphisms or value assignments. So any universe of interacting systems, including those functioning as measuring instruments, can be modelled quantum mechanically without the projection postulate. (shrink)

This paper explores the status of the von Neumann-Luders state transition rule (the "projection postulate") within "real-logic" quantum logic. The entire discussion proceeds from a reading of the Luders rule according to which, although idealized in applying only to "minimally disturbing" measurements, it nevertheless makes empirical claims and is not a purely mathematical theorem. An argument (due to Friedman and Putnam) is examined to the effect that QL has an explanatory advantage over Copenhagen and other interpretations which relativize (...) truth-value assignments to experimental arrangements. Two versions of QL, the lattice-theoretic (LT) and partial-Boolean-algebra (PBA), are considered. It turns out that the projection postulate is intimately connected with the choice of conditional connective for QL. The effect of the projection postulate is obtained with the Sasaki conditional. However, this choice is found to require extra assumptions, on both the LT and PBA versions, which are either just as ad hoc as the projection postulate itself or indefensible from within the real-logic QL framework. (shrink)

Much of the recent discussion of problematic aspects of quantum-mechanical measurement centers around that feature of quantum theory which is called "the projection postulate." This is roughly the claim that a change of a certain sort occurs in the state of a physical system when a measurement is made on the system. In this paper an argument for the projection postulate due to von Neumann is considered. Attention is focused on trying to provide an understanding of (...) the notion of "the state of a physical system" which is compatible with the argument von Neumann offers. An attempt is made to formulate the argument in terms of an objectivistic interpretation of probability concepts. It is seen that such an interpretation does not provide a suitable way of understanding the argument. An attempt is made to illustrate the source of this failure in terms of a non-quantum-mechanical example. (shrink)

I defend the projection postulate against two of Margenau's criticisms. One involves two types of nonideal measurements, measurements that disturb and measurements that annihilate. Such measurements cannot be characterized using the original version of the projection postulate. This is one of the most interesting and powerful objections to the projection postulate since most realistic measurements are nonideal, in Margenau's sense. I show that a straightforward generalization of the projection postulate is capable of (...) handling the more realistic kinds of measurements considered by Margenau. His other objection involves the EPR (Einstein-Podolsky-Rosen) situation. He suggests that there is a significant potential for violations of the no-superluminalsignals requirement of the special theory of relativity, if projections occur in this situation and others like it. He also suggests that what is paradoxical about this situation disappears if the projection postulate is rejected. I show that it is not possible to use measurements on pairs of spatially-separated systems whose states are entangled to transmit information superluminally, and generalize this result to include nonideal measurements. I also show that EPR's dilemma does not really depend on the projection postulate. (shrink)

It is suggested that the world is locally projectively flat rather than Euclidean. From this postulate it is shown that an (N+1)-particle system has the global geometry of the symmetric spaceSO(4,N+1)/SO(4)×SO(N+1). A complex representation also exists, with structureSU(2,N+1)/S[U(2)×U(N+1)]. Several aspects of these geometrics are developed. Physical states are taken to be eigenfunctions of the Laplace-Beltrami operators. The theory may provide a rational basis for comprehending the groupsSO(4, 2),SU(2)×U(1),SU(3), etc., of current interest.

A suitable unified statistical formulation of quantum and classical mechanics in a *-algebraic setting leads us to conclude that information itself is noncommutative in quantum mechanics. Specifically we refer here to an observer's information regarding a physical system. This is seen as the main difference from classical mechanics, where an observer's information regarding a physical system obeys classical probability theory. Quantum mechanics is then viewed purely as a mathematical framework for the probabilistic description of noncommutative information, with the projection (...) postulate being a noncommutative generalization of conditional probability. This view clarifies many problems surrounding the interpretation of quantum mechanics, particularly problems relating to the measuring process. (shrink)

In the Critique of Practical Reason, Kant grounds his postulate for the immortality of the soul on the presupposed practical necessity of the will’s endless progress toward complete conformity with the moral law. Given the important role that this postulate plays in Kant’s ethical and political philosophy, it is hard to understand why it has received relatively little attention. It is even more surprising considering the attention given to his other postulates of practical reason: the existence of God (...) and freedom. The project of this paper is to examine Kant’s postulate of the immortality of the soul, examine critiques of this argument, and show why the argument succeeds in showing that belief in the moral law also obligates one to believe in the soul’s immortality. (shrink)

Although the category “race” fails as a postulated natural kind, racial, ethnic, national, linguistic, religious, and other group designations might nonetheless be considered projectible insofar as they support inductive inferences in biomedicine. This article investigates what it might mean for group concepts in population genetics and genomics to be projectible and whether the projectibility of such predicates licenses the representation of their corresponding classes as natural kinds according to currently prevailing projectibility-based accounts of natural kinds. The article draws on a (...) case study from cancer genetics, specifically, breast cancer risk in Ashkenazi Jewish women. (shrink)

Born’s quantum probability rule is traditionally included among the quantum postulates as being given by the squared amplitude projection of a measured state over a prepared state, or else as a trace formula for density operators. Both Gleason’s theorem and Busch’s theorem derive the quantum probability rule starting from very general assumptions about probability measures. Remarkably, Gleason’s theorem holds only under the physically unsound restriction that the dimension of the underlying Hilbert space \ must be larger than two. Busch’s (...) theorem lifted this restriction, thereby including qubits in its domain of validity. However, while Gleason assumed that observables are given by complete sets of orthogonal projectors, Busch made the mathematically stronger assumption that observables are given by positive operator-valued measures. The theorem we present here applies, similarly to the quantum postulate, without restricting the dimension of \ and for observables given by complete sets of orthogonal projectors. We also show that the Born rule applies beyond the quantum domain, thereby exhibiting the common root shared by some quantum and classical phenomena. (shrink)

In this paper it is shown how a partial semantics for presuppositions can be given which is empirically more satisfactory than its predecessors, and how this semantics can be integrated with a technically sound, compositional grammar in the Montagovian fashion. Additionally, it is argued that the classical objection to partial accounts of presupposition projection, namely that they lack “flexibility,” is based on a misconception. Partial logics can give rise to flexible predictions without postulating any ad hoc ambiguities. Finally, it (...) is shown how the partial foundation can be combined with a dynamic system of common-ground maintenance to account for accommodation. (shrink)

This project is in the first place an attempt to clarify what transcendental logic is and how Kant uses it in order to achieve his goals. I use two keys in unlocking transcendental logic: Kant's philosophy of mathematics and his account of modality. I argue that Kant's categorical separation of philosophical and mathematical cognition in his reflections on method is too sweeping and undifferentiated to account for his practice in transcendental logic. On the basis of an examination of what it (...) would take in order to sustain Kant's claim for the peculiarity of modal judgments---their subjective syntheticity---I argue that the positive claims that transcendental logic makes regarding objects are legitimated by the construction of an object as such, whose concept is provided by the sum total of the categories. I suggest that the schemata play a role analogous to that of the a priori constructed figure in a mathematical proof and provide a reconstruction of the Transcendental Doctrine of the Capacity of Judgment which makes sense of Kant's decision to label the modal principles 'postulates' in the precise sense of the Euclidean mathematicians. Part Two argues that Kant's practical philosophy is grounded on something which deserves to be called a transcendental logic every bit as much as the logic that we find in the Critique of Pure Reason. Instead of being based upon our capacity for theoretical judgment, in which we refer a concept to an ontic object via intuition, practical transcendental logic is based upon our capacity for practical judgment , in which we refer a concept to a deontic object via feeling. I show how the central arguments of Kant's practical philosophy rely implicitly upon the construction of a good will as such, which plays a semantic role analogous to that of the object as such in theoretical philosophy. One part of my case is contained in the demonstration that 'good' functions as a practical modal concept and that predications of goodness have a peculiar logical form, analogous to that exhibited by theoretical predications of existence. (shrink)

In this expository article, a presentation is given of A.C. Crombie's life work in the history of science, Styles of Scientific Thinking in the European Tradition. The History of Argument and Explanation in the Mathematical and Biomedical Sciences and Arts (1994). The importance of this work for the philosophy of science and epistemology is comparable to the more renowned work of the 1960's and '70s, but threatens to be paradoxically overlooked because of its gigantic proportions. (No thorough study of the (...) book appeared up to now.) Crombie's earlier work started from a provocative version of continuism in the debate about the rise of modern science, ascribing the origin of the experimental tradition to methodological forebears in the thirteenth century (Grosseteste). Rather than revivifying this quarrel now, Crombie has offered us an emergentist picture of the rise of six subsequent major styles of science (using grand units of analysis) from the Greeks up to Darwin. These styles of thinking are superimposed upon another in that the definite breakthrough of each next style is consequent upon the recognition of the proper limits of the full grown previous style. In a first group, Crombie assembles three major styles for revealing regularities in individual phenomena, i.e. where the consideration of the collective to which the phenomenon belongs is not required for recognizing the regularity. Here we have (S1) the ancient style of postulating principles and entities according to a more or less apriorical evidence type or in axiomatic fashion; (S2) the experimental tradition from Alhazen up to Newton, and (S3) the style of hypothetical modelling, combining the former two in the vein of the rational artist as an (ultimately, also cognitive) engineer. In a second group the styles dealing with regularities discoverable only in a collectivity of phenomena are dealt with. Here we have the (S4) probabilistic style superimposed on the classical picture of rationality made up by the achieved styles in the first group. Then (S5) the taxonomic style is ready to be combined, finally, with S4, in order to discover the statistical economy of living nature in (S6), the 'genetic' style, culminating in Darwin's history of nature (which was to be expected). On the other hand, the latter style is traced back to the 16th and 17th century project of a history of languages and culture, of knowledge, and of mankind (which is a more surprising connection made by Crombie). In a final section some philosophical remarks are made regarding Crombie's project; mainly with respect to the larger perspective, in Crombie's terms, of an 'intellectual anthropology', or alternatively, in terms of a 'comparative epistemology'. Also the absence of a real analysis of the very concept of style is noted. (shrink)

The axioms of projective and affine plane geometry are turned into rules of proof by which formal derivations are constructed. The rules act only on atomic formulas. It is shown that proof search for the derivability of atomic cases from atomic assumptions by these rules terminates . This decision method is based on the central result of the combinatorial analysis of derivations by the geometric rules: The geometric objects that occur in derivations by the rules can be restricted to those (...) known from the assumptions and cases. This “subterm property” is proved by permuting suitably the order of application of the geometric rules. As an example of the decision method, it is shown that there cannot exist a derivation of Euclid’s fifth postulate if the rule that corresponds to the uniqueness of the parallel line construction is taken away from the system of plane affine geometry. (shrink)

At the present time, there are several interpretations and modes of Kant’s transcendental philosophy (TP). Which of these interpretations and modes of transcendentalism most adequately express the spirit of TP, i.e. can claim the title of the transcendental ones? For the explication of the ‘idea of transcendental philosophy’ [KrV, A1], here I distinguish two transcendental shifts: methodological and metaphysical ones, which in their totality predetermine the essence and set the specificity of Kant’s transcendental idealism. The methodological transcendental shift that Kant (...) postulates in his definitions of TP in the Critique of Pure Reason [KrV, A11; B25] represents a shift from studying of objects to the analysis and justification of our mode of cognition of objects. This shift sets a fairly wide range of a la Kantian a priori doctrines and predetermines the transcendental turn (Re–Transcendentalising) of modern philosophy. The metaphysical transcendental shift that can be correlated with “the altered method of our way of thinking [in metaphysics]” [KrV, BXVIII], is associated with the splitting of the “thing” into the actual object (or Kantian thing-in-itself) and object of experience (or Kantian appearance), and involves a transition from the study of thing-in-itself to the analysis of the appearance. More precisely, this shift finds its expression in the transcendental triad “object (thing-in-itself; Ding an sich) – appearance (Erscheinung) – representation (Vorstellung)”, which determines the ‘idea’ (essence) of transcendental idealism/metaphysics. (shrink)

RESUMEN. Este artículo trata sobre la labor llevada a cabo por el iusfilósofo Luis Recaséns Siches de renovación de la Filosofía del Derecho en España mediante la introducción de los postulados neokantianos y kelsenianos. Lo que se puede denominar el proyecto Recasens fue, sin embargo, abruptamente interrumpido por el estallido de la Guerra Civil. Las críticas al neokantismo que contiene fueron incorporadas en trabajos posteriores de Recasens, así como en la obra del profesor Legaz y Lacambra, conservando de este modo (...) el proyecto algo de su impulso inicial. ABSTRACT. This article addresses the renovation effort conducted by the Law philosopher Luis Recaséns Siches, who aimed to update Philosophy of Law in Spain through the introduction of neokantian and kelsenian postulates. What can be denominated as “the Recaséns’ project” was, however, harshly interrupted by the outbreak of the Spanish Civil War. The judgments targeting neokantism that can be found in such texts were included in Recaséns’ later publications, as well as in the work of the professor Legaz y Lacambra, hence yielding the project to maintain some of its original impulse. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Philosophy and Rhetoric 37.1 (2004) 1-20 [Access article in PDF] Endoxa, Epistemological Optimism, and Aristotle's Rhetorical Project Ekaterina V. Haskins Communication Department Boston College Aristotle's crucial role in institutionalizing the art of rhetoric in the fourth century BCE is beyond dispute, but the significance of Aristotle's rhetorical project remains a point of lively controversy among philosophers and rhetoricians alike. There are many ways of reading and evaluating Aristotle's Rhetoric (...) that depend on the philosophical, theoretical, and pedagogical purposes of the scholar.1 Most philosophical and rhetorical exegeses of the Rhetoric, however, while focusing on the text's connections to Aristotle's corpus and to the rhetorical tradition before and after Aristotle, seem to lack a critical perspective on Aristotle's relationship with his cultural context. Yet, like other parts of Aristotle's encyclopedic intellectual endeavor, much of Rhetoric 's cultural content was provided by endoxa, "reputable or received opinions."Since G. E. L. Owen's essay "Tithenai ta phainomena" (1961) many scholars have accepted the claim that endoxa, rather than empirical observations, are the source of Aristotle's own philosophical principles. The "linguistic" turn within Aristotelian studies has drawn attention to the role of "facts" of language and ordinary experience within Aristotle's philosophical method. As a result, a view of Aristotle as a hard-core empiricist has given way to a picture of a humanist who is attuned to the nuances of his cultural milieu. Still, this new portrait fails to take into account that Aristotle's manner of selecting and categorizing his linguistic resources allows him to transform what we would consider cultural beliefs into natural, and hence, atemporal premises. This pattern can be explained by Aristotle's "epistemological optimism," in itself a blend of several cultural assumptions about perception in general and vision in particular, the function of language, and the cyclical nature of human history. Part of this essay's objective, then, will be an explanation of these components of Aristotle's epistemological optimism. By appreciating Aristotle's difference [End Page 1] on these issues from our modern assumptions, we will be in a better position to understand why Aristotle relies on endoxa on all three levels of philosophical discourse (theoretical science, moral philosophy, and productive arts of poetics and rhetoric). Aristotle remains consistent in his treatment of endoxa throughout; rhetoric, however, presents a major challenge to Aristotle's epistemological optimism and his conception of language. I shall argue that Aristotle recognized this challenge and that he answered it by isolating proofs and rhetorical genres from their linguistic medium (lexis ), and postulating linguistic transparency (sapheneia ) as a stylistic norm. I. Aristotle's openness to appearances (phainomena ) and opinions (endoxa ) was accorded prominence especially thanks to the work of G. E. L. Owen and Martha Nussbaum. Owen was first to defend a linguistic translation of Aristotle's phainomena as "ordinary beliefs" and "appearances" against the then-prevalent rendition "observed facts." In so doing he asserted the crucial impact of the philosopher's cultural context on the formation of speculative discourse. Owen (1961) nonetheless demanded that phainomena be understood as empirical observations in Aristotle' treatises on biology and meteorology (84-86), so as to preserve the methodological and epistemological distinctions between inquiries into the natural world, on the one hand, and the world inhabited by human agents, on the other. Nussbaum (1986) went much further than Owen in asserting the role of phainomena and endoxa in Aristotle's inquiry. Unlike Owen, Nussbaum sees no fundamental difference between "experiences" of a philosopher and linguistic expressions of cultural beliefs and interpretations—his discursive data—from which Aristotle constructs his philosophical accounts. Nussbaum's chief (and highly influential) claim is that Aristotle's method is marked by a deep concern for the experiential world of his fellow men and their language. Aristotle's philosophical insights into the human condition, on this reading, echo and amplify classical Greek tragedy, despite the austere diction of Aristotle's extant treatises.Owing to this openness to the world of ordinary beliefs, Aristotle seems to depart from the Eleatic and Platonic distrust of human... (shrink)

The standard axiomatization of quantum mechanics (QM) is not fully explicit about the role of the time-parameter. Especially, the time reference within the probability algorithm (the Born Rule, BR) is unclear. From a probability principle P1 and a second principle P2 affording a most natural way to make BR precise, a logical conflict with the standard expression for the completeness of QM can be derived. Rejecting P1 is implausible. Rejecting P2 leads to unphysical results and to a conflict with a (...) generalization of P2, a principle P3. All three principles are shown to be without alternative. It is thus shown that the standard expression of QM completeness must be revised. An absolutely explicit form of the axioms is provided, including a precise form of the projection postulate. An appropriate expression for QM completeness, reflecting the restrictions of the Gleason and Kochen-Specker theorems is proposed. (shrink)

Based on the theory of self-organization, the objective of this paper is tocritically discuss the theses defended by the postulators of two projects that aim toimprove human nature: eugenics and transhumanism. We will try to show that the“science of eugenics”, proposed by Francis Galton, and the contemporarytranshumanist project, outlined since the second half of the 20th century, share thecontroversial belief that human beings, through science and technology, are able tosuccessfully control the evolutionary processes of human species. We will try to (...) showthat this belief disregards the central characteristics of the complex self-organizedadaptive evolutionary processes of organisms in general. For this purpose, we willcritically analyse the central theses of the transhumanist project and the “status quo bias”argument proposed by Bolton and Ord in defence of such theses. We conclude byemphasizing that the proponents of the contemporary transhumanist project would benefitfrom a fallibilistic perspective that would allow them to face the project's social andethical possible implications with epistemic prudence. (shrink)

The article is devoted to the study of the philosophy of the common cause of N.F. Fedorov (1829–1903). The ideas related to the active-historical function of humanity in the world ontology are the subject of analytical attention. The method of meaningful analysis re­veals the main intentions of cosmosophy, aimed at the implementation of the project for the comprehensive regulation of nature and for the ontological transformation of the world. A semantic disclosure of a number of systemic categories of the philosophy (...) of cosmism is proposed and the fundamental concept of unrelatedness is explicated. It is noted that projectivism that draws a sharp line between cosmosophy and contemplative cosmic views is a carrier methodological principle of the cosmosophical paradigm. Fe­dorov’s teaching is characterized as an axiological system of supramoralism, aimed at changing the spontaneous natural order, transforming the empirical being. Based on this, it is concluded that Fedorov’s teaching can be defined as a cultural-evolutionary deonto­logy, postulating the need for a conscious stage of the global evolutionary process. It is noted that the axiomatics of the philosophy of cosmism is based on the traditions of the Orthodox creed. At the same time, it is the projective attitude to the world that makes it possible to realize the historical potential of Christianity as a “living religion” that synthesizes science, art and creed. Supramoralism proposes a project of creative eschato­logy, opposed to the passive expectation of a history catastrophic break. Cosmosophy af­firms the imperative of a real apocatastasis, requiring the physical resurrection of all gen­erations of dead people. It is concluded that the target historiosophical vector of cosmism determines the transition of an adult society into a god-like state. (shrink)

The Principia Cybernetica Project was created to develop an integrated philosophy or world view, based on the theories of evolution, self-organization, systems and cybernetics. Its conceptual network has been implemented as an extensive website. The present paper reviews the assumptions behind the project, focusing on its rationale, its philosophical presuppositions, and its concrete methodology for computer-supported collaborative development. Principia Cybernetica starts from a process ontology, where a sequence of elementary actions produces ever more complex forms of organization through the mechanism (...) of variation and selection, and metasystem transition. Its epistemology is constructivist and evolutionary: models are constructed by subjects for their own purposes, but undergo selection by the environment. Its ethics takes fitness and the continuation of evolution as the basic value, and derives more concrete guidelines from this implicit purpose. Together, these postulates and their implications provide answers to a range of age-old philosophical questions. (shrink)

In this essay I wish to add my voice to Michael H. Mitias’s polemic with Robert E. Allinson’s view that an Enlightenment-driven reform of the human world is desirable, and even necessary. Allinson calls the outcome of such a reform the “New Enlightenment.” I also consider the few main threads of Mitias’s alternative proposal for repairing the human world, which involves the reinterpretation of the Enlightenment ideology, and I strive to show that, contrary to Mitias’s belief, both his and Allinson’s (...) positions have important common points. Moreover, I also take a closer look at Mitias’s project, especially his postulate to begin funding the reforming of the human world in human nature. (shrink)

This chapter expounds Hacking’s project of styles of reasoning more systematically than Hacking himself has done, while the following chapters examine its philosophical implications. I shall show that, in addition to the statistical and the laboratory style described in Chap. 3, there exist other four styles of reasoning that share a set of common characterizing features: the algorithmic, the postulational, the historico-genetic and the taxonomic style of reasoning. All the differences notwithstanding, striking parallels can be drawn between these different styles (...) of reasoning: they emerged suddenly at certain points in time, crystallized around communities that shared certain standards of evidence and represent basic and inescapable forms of reasoning. Finally, I shall argue that there are other ways of thinking that differ from styles of reasoning in the sense of Hacking. What I consider a relevant difference is that only styles of reasoning have strong techniques of self-authentication, techniques that are intrinsic to their forms of reasoning. (shrink)

Despite the historical and contemporary significance of the Sharia, it has not yet been possible to solve the puzzle of its origins. Whereas previous research has postulated a greater or lesser degree of endogenous Islamic development, the present study reaches a different conclusion, namely that at the end of the 8th century Muslim state lawyers in Baghdad codified an Islamic "Imperial Law", oriented strongly towards Roman-Byzantine law. It is part of an Islamic-Byzantine context, and can only be explained against this (...) intercultural background. (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)

It is argued that formal reconstructions of the EPR-argument do not only show semantical incompleteness, but also incorrectness of quantum mechanics together with the projection postulate. The latter has to be rejected because it contradicts Schrödinger's equation. A logical analogon to the problem is given.

The so-called quantum Zeno effect is essentially a consequence of the projection postulate for ideal measurements. To test the effect, Itanoet al. have performed an experiment on an ensemble of atoms where rapidly repeated level measurements were realized by means of short laser pulses. Using dynamical considerations, we give an explanation why the projection postulate can be applied in good approximation to such measurements. Corrections to ideal measurements are determined explicitly. This is used to discuss how (...) far the experiment of Itanoet al. can be considered as a test of the quantum Zeno effect. We also analyze a new possible experiment on a single atom where stochastic light and dark periods can be interpreted as manifestation of the quantum Zeno effect. We show that the measurement point of view gives a quick and intuitive understanding of experiments of the above type, although a finer analysis has to take the corrections into account. (shrink)

What is called ``orthodox'' quantum mechanics, as presented in standard foundational discussions, relies on two substantive assumptions --- the projection postulate and the eigenvalue-eigenvector link --- that do not in fact play any part in practical applications of quantum mechanics. I argue for this conclusion on a number of grounds, but primarily on the grounds that the projection postulate fails correctly to account for repeated, continuous and unsharp measurements and that the eigenvalue-eigenvector link implies that virtually (...) all interesting properties are maximally indefinite pretty much always. I present an alternative way of conceptualising quantum mechanics that does a better job of representing quantum mechanics as it is actually used, and in particular that eliminates use of either the projection postulate or the eigenvalue-eigenvector link, and I reformulate the measurement problem within this new presentation of orthodoxy. (shrink)

Facts happen at every interaction, but they are not absolute: they are relative to the systems involved in the interaction. Stable facts are those whose relativity can effectively be ignored. In this work, we describe how stable facts emerge in a world of relative facts and discuss their respective roles in connecting quantum theory and the world. The distinction between relative and stable facts resolves the difficulties pointed out by the no-go theorem of Frauchiger and Renner, and is consistent with (...) the experimental violation of the Local Friendliness inequalities of Bong et al.. Basing the ontology of the theory on relative facts clarifies the role of decoherence in bringing about the classical world and solves the apparent incompatibility between the ‘linear evolution’ and ‘projection’ postulates. (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)

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 a cloud chamber, the quantum measurement problem amounts to explaining the first droplet in a charged-particle track; subsequent droplets are explained by Mott’s 1929 wave-theoretic argument about collision-induced wavefunction collimation. I formulate a mechanism for how the first droplet in a cloud chamber track arises, making no reference to quantum measurement axioms. I look specifically at tracks of charged particles emitted in the simplest slow decays, because I can reason about rather than guess the form that wave packets take. (...) The first visible droplet occurs when a randomly occurring, barely-subcritical vapor droplet is pushed past criticality by ionization triggered by the faint wavefunction of the emitted charged particle. This is possible because potential energy incurred when an ionized vapor molecule polarizes the other molecules in a droplet can balance the excitation energy needed for the emitted charged particle to create the ion in the first place. This degeneracy is a singular condition for Coulombic scattering, leading to infinite or near-infinite ionization cross sections, and from there to an emergent Born rule in position space, but not an operator projection as in the projection postulate. Analogous mechanisms may explain canonical quantum measurement behavior in detectors such as ionization chambers, proportional counters, photomultiplier tubes or bubble chambers. This work is important because attempts to understand canonical quantum measurement behavior and its limitations have become urgent in view of worldwide investment in quantum computing and in searches for super-rare processes. (shrink)

In a recent paper, Michael Friedman and Hilary Putnam argued that the Luders rule is ad hoc from the point of view of the Copenhagen interpretation but that it receives a natural explanation within realist quantum logic as a probability conditionalization rule. Geoffrey Hellman maintains that quantum logic cannot give a non-circular explanation of the rule, while Jeffrey Bub argues that the rule is not ad hoc within the Copenhagen interpretation. As I see it, all four are wrong. Given that (...) there is to be a projection postulate, there are at least two natural arguments which the Copenhagen advocate can offer on behalf of the Luders rule, contrary to Friedman and Putnam. However, the argument which Bub offers is not a good one. At the same time, contrary to Hellman, quantum logic really does provide an explanation of the Luders rule, and one which is superior to that of the Copenhagen account, since it provides an understanding of why there should be a projection postulate at all. (shrink)

This is the second, mathematically more detailed part of a paper consisting of two articles, the first having appeared in the immediately preceding issue of this Journal. It shows that a measurement converts a pure case into a mixture with reducible probabilities. The measurement as such permits no inference whatever as to the state of the physical system subjected to measurement after the measurement has been performed. But because the probabilities after the act are classical and therefore reducible, it is (...) often possible to adjust them so that Von Neumann's projection postulate is true. Among the more specific features dealt with in Part II is the occurrence of negative joint probabilities for the measurement of non-commuting operators in certain (not all!) quantum states. The general conclusions reached are stated at the end of the article. (shrink)

The extended semantic realism (ESR) model proposes a new theoretical perspective which embodies the mathematical formalism of standard (Hilbert space) quantum mechanics (QM) into a noncontextual framework, reinterpreting quantum probabilities as conditional instead of absolute. We provide in this review an overall view on the present status of our research on this topic. We attain in a new, shortened way a mathematical representation of the generalized observables introduced by the ESR model and a generalization of the projection postulate (...) of elementary QM. Basing on these results we prove that the Bell-Clauser-Horne-Shimony-Holt (BCHSH) inequality, a modified BCHSH inequality and quantum predictions hold together in the ESR model because they refer to different parts of the picture of the physical world supplied by the model. Then we show that a new mathematical representation of mixtures must be introduced in the ESR model which does not coincide with the standard representation in QM and avoids some deep problems that arise from the representation of mixtures provided by QM. Finally we get a nontrivial generalization of the Lüders postulate, which is justified in a special case by introducing a reasonable physical assumption on the evolution of the compound system made up of the measured system and the measuring apparatus. (shrink)

Accepted quantum description is stochastic, yet history is nonstochastic, i.e., not representable by a probability distribution. Therefore ordinary quantum mechanics is unsuited to describe history. This is a limitation of the accepted quantum theory, rather than a failing of mechanics in general. To remove the limitation, it would be desirable to find a form of quantum mechanics that describes the future stochastically and the past nonstochastically. For this purpose it proves sufficient to introduce into quantum mechanics, by means of a (...) perfected formal correspondence, certain analogs of the classical initial-condition constants. Through the restoration of such parameters at the quantum level one accomplishes a natural accommodation of time anisotropy, wave-function reduction, and “event” description by quantum mechanical equations of motion alone, without the need for extra postulates (e.g., a projection postulate). This requires a complete restructuring of quantum measurement theory. (shrink)

Is the Copenhagen interpretation really a subjective one? What is the special role that observations play in quantum theory? Is there really something peculiar about the projection postulate? Why does the Copenhagenist treat probabilities as properties of individual systems? Is there a measurement problem, and if so, can itin principle be solved within the framework of quantum theory? We offer aconceptual treatment of the Copenhagen interpretation of quantum mechanics in which these questions are answered and contrast it with (...) another interpretation which we call Popperism. The interpretations differ in their choice of a state description, from which it follows that they will offer a different account of the relation of measurements to states and different ways of describing quantum theory. But the two descriptions are equally consistent and physically completely equivalent. (shrink)

The EPR problem is studied both from an instrumentalistic and from a realistic point of view. Bohr's reply to the EPR paper is analyzed and demonstrated to be not completely representative of Bohr's general views on the possibility of defining properties of a microscopic object. A more faithful Bohrian answer would not have led Einstein to the conclusion that Bohr's completeness claim of quantum mechanics implies nonlocality. The projection postulate, already denounced in 1936 by Margenau as the source (...) of the EPR paradox, is found to be also at the origin of the nonlocality conundrum. Its unobservability in EPR-like experiments is demonstrated, thus showing the redundancy of the idea of nonlocality in the instrumentalist interpretation of quantum mechanics. It is argued that also from a realist point of view there is no reason to assume nonlocality. The relevance of Bohm's quantum potential and of Bell's inequalities with respect to the (non)locality problem is discussed. (shrink)

Heisenberg'sgendanken experiments in quantum mechanics have given rise to a widespread belief that the indeterminacy relations holding for the variables of a quantal system can be explained quasiclassically in terms of a disturbance suffered by the system in interaction with a quantal measurement, or state preparation, agent. There are a number of criticisms of this doctrine in the literature, which are critically examined in this article and found to be ininconclusive, the chief error being the conflation of this disturbance with (...) the projection postulate. We present a critique of the disturbance theory based on the fact that the required disturbance will in general depend on the interaction time of the system and state-preparer. This point is exploited in the construction of a spin-interaction model which acts as a counterexample to the disturbance doctrine, while remaining faithful to the spirit of Heisenberg'sgedanken experiments. Several consequences of this result are discussed. (shrink)