What would it mean to apply quantum theory, without restriction and without involving any notion of measurement and state reduction, to the whole universe? What would realism about the quantum state then imply? This book brings together an illustrious team of philosophers and physicists to debate these questions. The contributors broadly agree on the need, or aspiration, for a realist theory that unites micro- and macro-worlds. But they disagree on what this implies. Some argue that if unitary quantum evolution has (...) unrestricted application, and if the quantum state is taken to be something physically real, then this universe emerges from the quantum state as one of countless others, constantly branching in time, all of which are real. The result, they argue, is many worlds quantum theory, also known as the Everett interpretation of quantum mechanics. No other realist interpretation of unitary quantum theory has ever been found. Others argue in reply that this picture of many worlds is in no sense inherent to quantum theory, or fails to make physical sense, or is scientifically inadequate. The stuff of these worlds, what they are made of, is never adequately explained, nor are the worlds precisely defined; ordinary ideas about time and identity over time are compromised; no satisfactory role or substitute for probability can be found in many worlds theories; they can't explain experimental data; anyway, there are attractive realist alternatives to many worlds. Twenty original essays, accompanied by commentaries and discussions, examine these claims and counterclaims in depth. They consider questions of ontology - the existence of worlds; probability - whether and how probability can be related to the branching structure of the quantum state; alternatives to many worlds - whether there are one-world realist interpretations of quantum theory that leave quantum dynamics unchanged; and open questions even given many worlds, including the multiverse concept as it has arisen elsewhere in modern cosmology. A comprehensive introduction lays out the main arguments of the book, which provides a state-of-the-art guide to many worlds quantum theory and its problems. (shrink)

This volume complements two highly successful previously published volumes of Richard Rorty's philosophical papers: Objectivity, Relativism, and Truth, and Essays on Heidegger and Others. The essays in the volume engage with the work of many of today's most innovative thinkers including Robert Brandom, Donald Davidson, Daniel Dennett, Jacques Derrida, Jürgen Habermas, John McDowell, Hilary Putnam, John Searle, and Charles Taylor. The collection also touches on problems in contemporary feminism raised by Annette Baier, Marilyn Frye, and Catherine MacKinnon, and considers issues (...) connected with human rights and cultural differences. Anyone with a serious interest in contemporary philosophy and what it can do for us in the modern world will enjoy this invaluable collection. (shrink)

The central claim that understanding quantum mechanics requires a conscious observer, which is made by B. Rosenblum and F. Kuttner in their book “Quantum Enigma: Physics encounters consciousness”, is shown to be based on various misunderstandings and distortions of the foundations of quantum mechanics.

While its applications have made quantum theory arguably the most successful theory in physics, its interpretation continues to be the subject of lively debate within the community of physicists and philosophers concerned with conceptual foundations. This situation poses a problem for a pragmatist for whom meaning derives from use. While disputes about how to use quantum theory have arisen from time to time, they have typically been quickly resolved, and consensus reached, within the relevant scientific sub-community. Yet rival accounts of (...) the meaning of quantum theory continue to proliferate . In this article I offer a diagnosis of this situation and outline a pragmatist solution to the problem it poses, leaving further details for subsequent articles. (shrink)

Jeffrey Barrett presents the most comprehensive study yet of a problem that has puzzled physicists and philosophers since the 1930s.

These articles and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the papers are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Includes an essay in which Bohr and Einstein discuss quantum and_wave equation theories. 1961 edition.

Vaihinger... shows that thought is primarily a biological function turned into a conscious art. It is an art of adjustment, whose chief instrument is the construction of fictions by which men may manage to live. Thought is to be tested not by correspondence to an objective reality (that fiction is neatly disposed of) nor by its mirroring in consciousness an objective external world. Thought is to be tested by its fruits. The constructions of thought are not copies of or transcripts (...) of reality; they are programs, guess-work plans; possible programs for operation. Their validity is to be measured not by verisimilitude but by value. The fruits of thought are not "true," but especially where they are false, it may be important to act as if they were true... Vaihinger's chief originality consists in his defining of fictions and his distinction of fictions from hypotheses on the one hand, and from dogmatisms on the other. An hypothesis is a tentative discovery about the universe; a fiction is a deliberate, often clearly false and internally contradictory invention of thought... Evolution is the hypothesis that man is descended from the lower animals. We assume that we can indirectly turn to the remote facts which would justify that hypothesis. But the concept of infinity in the calculus, the atom and the ether in physics, the economic man in Adam Smith, are deliberate self-contradictory fictions, and fictions at variance with all experience. But though they are not only imaginary, false to the reality they allegedly represent and logically incoherent, they nevertheless facilitate thought and proper action. They are vital lies, human conveniences. They are the faiths, the palpably false faiths, the clearly useful falsities by which we live... The discovery that fictions were fictions has led, in the past, says Vaihinger, to an abandonment of them, and a turning to other fictions believed to be truer. Pathetic and foolish adventure! What the race needs is more faith in its own effective imaginations. The myths that it has told itself, the world pictures that it has made, are not to be dismissed because they are found to be creations of the imagination. They tally with no world and they carry the canker of logical inconsistency within them. The important thing is their utility; their human scope and mortal relevance. If we ceased making fictions, we should cease altogether to be. Let us beware to plunge from fruitful fictions to less fruitful ones that masquerade as truths and are really dogmatisms. (Review of As If by Irwin Edman, Saturday Review of Literature, 10 January, 1925) This is a well-formatted version of C.K. Ogden's translation of Philosophie des Als Ob, originally published in 1925 by Kegan Paul. (shrink)

Presents German physicist Werner Heisenberg's 1958 text in which he discusses the philosophical implications and social consequences of quantum mechanics and other physical theories.

This book comes to the rescue of scientific realism, showing that reports of its death have been greatly exaggerated. Philosophical realism holds that the aim of a particular discourse is to make true statements about its subject matter. Ilkka Niiniluoto surveys different kinds of realism in various areas of philosophy and then sets out his own critical realist philosophy of science.

This book is about how to understand quantum mechanics by means of a modal interpretation. Modal interpretations provide a general framework within which quantum mechanics can be considered as a theory that describes reality in terms of physical systems possessing definite properties. Quantum mechanics is standardly understood to be a theory about probabilities with which measurements have outcomes. Modal interpretations are relatively new attempts to present quantum mechanics as a theory which, like other physical theories, describes an observer-independent reality. In (...) this book, Pieter Vermaas summarises the results of this work. The book will be of great value to undergraduates, graduate students and researchers in philosophy of science, and physics departments with an interest in learning about modal interpretations of quantum mechanics. (shrink)

Thomas S. Kuhn's classic book is now available with a new index.

A Philosopher Looks at Quantum Mechanics’ (Putnam [1965]) explained why the interpretation of quantum mechanics is a philosophical problem in detail, but with only the necessary minimum of technicalities, in the hope of making the difficulties intelligible to as wide an audience as possible. When I wrote it, I had not seen Bell ([1964]), nor (of course) had I seen Ghirardi et al. ([1986]). And I did not discuss the ‘Many Worlds’ interpretation. For all these reasons, I have decided to (...) make a similar attempt forty years later, taking account of additional interpretations and of our knowledge concerning non-locality. (The Quantum Logical interpretation proposed in Putnam [1968] is not considered in the present paper, however, because Putnam [1994b] concluded that it was unworkable.) Rather than advocate a particular interpretation, this paper classifies the possible kinds of interpretation, subject only to the constraints of a very broadly construed scientific realism. Section 7 does, however, argue that two sorts of interpretation—ones according to which a ‘collapse’ is brought about by the measurement (e.g. the traditional ‘Copenhagen’ interpretation), and the Many Worlds interpretation or interpretations—should be ruled out. The concluding section suggests some possible morals of a cosmological character. Background Scientific realism is the premise of my discussion What ‘quantum mechanics’ says—and some problems Other interpretations of quantum mechanics The problem of Einstein's bed Classification of the possible kinds of interpretation Which interpretations I think we can rule out The ‘moral’ of this discussion. (shrink)

This essay contains a partial exploration of some key concepts associated with the epistemology of realist philosophies of science. It shows that neither reference nor approximate truth will do the explanatory jobs that realists expect of them. Equally, several widely-held realist theses about the nature of inter-theoretic relations and scientific progress are scrutinized and found wanting. Finally, it is argued that the history of science, far from confirming scientific realism, decisively confutes several extant versions of avowedly 'naturalistic' forms of scientific (...) realism. (shrink)

What is commonly known as the Copenhagen interpretation of quantum mechanics, regarded as representing a unitary Copenhagen point of view, differs significantly from Bohr's complementarity interpretation, which does not employ wave packet collapse in its account of measurement and does not accord the subjective observer any privileged role in measurement. It is argued that the Copenhagen interpretation is an invention of the mid‐1950s, for which Heisenberg is chiefly responsible, various other physicists and philosophers, including Bohm, Feyerabend, Hanson, and Popper, having (...) further promoted the invention in the service of their own philosophical agendas. (shrink)

The discussion of determinism/indeterminism in the natural world is not only a concern for epistemology and philosophy of science; it also has strong implications for natural theology. On the one hand, the distinction between determinism and predictability has led to deeper research into the relationship between ontological and gnoseological realms. On the other hand, the multiple descriptions proposed by contemporary science cannot avoid the question of the cognitive status of the various scientific formulations and the possibility of a coexistence of (...) deterministic and indeterministic views. This chapter presents the methodological proposal of the abandonment of the mental limit which entails a deep renunciation of any form of monism and of the kind of uniqueness that results from resting at an objectification. Methodic-thematic pluralism not only relates the gnoseological to the ontological realms without confusing them, but also paves the way for establishing the cognitive status of the different scientific disciplines avoiding reduction. (shrink)

Attempts to solve the issue of divine action in nature have resulted in many innovative proposals seeking to explain how God can act within nature without disrupting the created order but introducing novelty in the history of the universe. My goal is to show how Aquinas' doctrine of providence, mainly as expressed in his De Potentia Dei, fulfils the criteria for an account of divine action: that God's action is providential in the sense that God is involved in the individual (...) and particular here and now. -/- . (shrink)

Contrary to classical physics, which was strongly objective i.e. could be interpreted as a description of mind-independent reality, standard quantum mechanics (SQM) is only weakly objective, that is to say, its statements, though intersubjectively valid, still merely refer to operations of the mind. Essentially, in fact, they are predictive of observations. On the view that SQM is universal conventional realism is thereby refuted. It is shown however that this does not rule out a broader form of realism, called here ‘open (...) realism’, restoring the notion of mind-independent reality. (shrink)

Andrew Eshleman has argued that atheists can believe in God by being fully engaged members of religious communities and using religious discourse in a non-realist way. He calls this position 'fictionalism' because the atheist takes up religion as a useful fiction. In this paper I critique fictionalism along two lines: that it is problematic to successfully be a fictionalist and that fictionalism is unjustified. Reflection on fictionalism will point to some wider problems with religious anti-realism.

The notion of reality in the physical world has become, during the last century, somewhat problematic. The contrast between the simple and obvious reality of the innumerable instruments, machines, engines, and gadgets produced by our technological industry, which is applied physics, and of the vague and abstract reality of the fundamental concepts of physical science, as forces and fields, particles and quanta, is doubtlessly bewildering. There has already developed a gap between pure and applied science and between the groups of (...) men devoted to the one or the other activity, a separation that may lead to a dangerous estrangement. Physics needs a unifying philosophy, expressible in ordinary language, to bridge this gulf between "reality" as thought of in practice and in theory. I am not a philosopher but a theoretical physicist. I cannot provide a well balanced philosophy of science that would take due account of the ideas developed by differing schools, but I shall endeavor to formulate some ideas which have helped me in my own struggle with these problems. (shrink)

On several occasions I have pointed out that the lesson taught us by recent developments in physics regarding the necessity of a constant extension of the frame of concepts appropriate for the classification of new experiences leads us to a general epistemological attitude which might help us to avoid apparent conceptual difficulties in other fields of science as well. Since, however, the opinion has been expressed from various sides that this attitude would appear to involve a mysticism incompatible with the (...) true spirit of science, I am very glad to use the present opportunity of addressing this assembly of scientists working in quite different fields but united in their striving to find a common ground for our knowledge, to come back to this question, and above all to try to clear up the misunderstandings which have arisen. (shrink)

Kellert (In the Wake of Chars, University of Chicago press, Chicago, 1993) has argued that Laplacean determinism in classical physics is actually a layered concept, where various properties or layers composing this form of determinism can be peeled away. Here, I argue that a layered conception of determinism is inappropriate and that we should think in terms of different deterministic models applicable to different kinds of systems. The upshot of this analysis is that the notion of state is more closely (...) tied to the kind of system being investigated than is usually considered in discussions of determinism. So when investigating determinism corresponding changes to the appropriate notion of state – and, perhaps, the state space itself – also need to be considered. (shrink)

Essays discuss relativism, knowledge, creativity, progress, Aristotle, Galileo, cultural pluralism, and reason.

Papers resulting from a conference at the Center for Theology and the Natural Sciences, Berkeley, Calif., Aug. 1993.

Debates about scientific realism are closely connected to almost everything else in the philosophy of science, for they concern the very nature of scientific knowledge. Scientific realism is a positive epistemic attitude toward the content of our best theories and models, recommending belief in both observable and unobservable aspects of the world described by the sciences. This epistemic attitude has important metaphysical and semantic dimensions, and these various commitments are contested by a number of rival epistemologies of science, known collectively (...) as forms of scientific antirealism. This article explains what scientific realism is, outlines its main variants, considers the most common arguments for and against the position, and contrasts it with its most important antirealist counterparts. (shrink)

The aim of this paper is to introduce a new member of the family of the modal interpretations of quantum mechanics. In this modal-Hamiltonian interpretation, the Hamiltonian of the quantum system plays a decisive role in the property-ascription rule that selects the definite-valued observables whose possible values become actual. We show that this interpretation is effective for solving the measurement problem, both in its ideal and its non-ideal versions, and we argue for the physical relevance of the property-ascription rule by (...) applying it to well-known physical situations. Moreover, we explain how this interpretation supplies a description of the elemental categories of the ontology referred to by the theory, where quantum systems turn out to be bundles of possible properties. (shrink)

Cet ouvrage, un grand classique désormais, son auteur l'a écrit pour répondre au "devoir qui s'impose, aujourd'hui plus que jamais, aux hommes de science de penser leur discipline dans l'ensemble de la culture moderne pour l'enrichir non seulement de connaissances techniquement importantes, mais aussi des idées venues de leur science qu'ils peuvent croire humainement signifiantes. L ingénuité même d'un regard neuf (celui de la science l'est toujours) peut parfois éclairer d'un jour nouveau d'anciens problèmes...".

The recent debates concerning divine action in the context of quantum mechanics are examined with particular reference to the work of William Pollard, Robert J. Russell, Thomas Tracy, Nancey Murphy, and Keith Ward. The concept of a quantum mechanical “event” is elucidated and shown to be at the center of this debate. An attempt is made to clarify the claims made by the protagonists of quantum mechanical divine action by considering the measurement process of quantum mechanics in detail. Four possibilities (...) for divine influence on quantum mechanics are identified and the theological and scientific implications of each discussed. The conclusion reached is that quantum mechanics is not easily reconciled with the doctrine of divine action. (shrink)

. Donald MacKay has suggested that the logical concept of complementarity is needed to relate scientific and theological thinking. According to Ian Barbour, this concept should only be used within, not between, disciplines. This article therefore attempts to clarify that contrast from the standpoint of cognitive process. Thinking in terms of complementarity is explicated within a structuralist‐genetic, interactive‐constructivist, developmental theory of the neo‐ and post‐Piagetian kind, and its role in religious development is indicated. Adolescents'complementary views on Creation and on the (...) corresponding scientific accounts serve as an illustration. After further analysis of parallel and circular complementarity, it is shown under which conditions complementarity of science and theology can be better justified and may be potentially more fruitful than is apparent from Barbour's or even MacKay's considerations. (shrink)

. Neither the correspondence nor the coherence theory of truth does justice to the truth claims made in science and theology. I propose a new definition that relates truth to solving puzzles. I claim that this definition is more adequate than either of the traditional theories and that it offers two additional benefits: first, it provides grounds for a theory regarding the relations between theology and science that may stand up better to philosophical scrutiny than does critical realism; and second, (...) it blocks the move to relativism based on recognition of the plurality of perspectives and the historical and social conditioning of knowledge. (shrink)