A reply to a comment by Paul Tappenden (BJPS 59 (2008) pp. 307-314) on S. Saunders and D. Wallace, "Branching and Uncertainty" (BJPS 59 (2008) pp. 298-306).

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)

Relativistic quantum theory poses a number of conceptual problems over and above the non-relativistic mechanics. From a purely mathematical point of view it is also much more sophisticated. Even the kinematic theory poses considerable difficulties: locality, antimatter, negative energy, and charge are already systematically linked in ways that cannot simply be paraphrased. A further complication is that in the midst of this structure we have what is usually called the Newton-Wigner representation (or, in the case of the Dirac theory, the (...) Foldy-Wouthuysen representation), in which fields and states are no longer covariantly described and where the “local” self-adjoint quantities (NW-local observables) do not obey microcausality, but only satisfy equal-time commutators with respect to a particular inertial frame. If we pass to this represenation, we obtain at a stroke the basic structure of non-relativistic quantum field theory; it is not too hard to descend from that to a many-particle mechanics, and to recover the usual definitions of localization. (shrink)

Category Theory has developed rapidly. This book aims to present those ideas and methods which can now be effectively used by Mathe­ maticians working in a variety of other fields of Mathematical research. This occurs at several levels. On the first level, categories provide a convenient conceptual language, based on the notions of category, functor, natural transformation, contravariance, and functor category. These notions are presented, with appropriate examples, in Chapters I and II. Next comes the fundamental idea of an adjoint (...) pair of functors. This appears in many substantially equivalent forms: That of universal construction, that of direct and inverse limit, and that of pairs offunctors with a natural isomorphism between corresponding sets of arrows. All these forms, with their interrelations, are examined in Chapters III to V. The slogan is "Adjoint functors arise everywhere". Alternatively, the fundamental notion of category theory is that of a monoid -a set with a binary operation of multiplication which is associative and which has a unit; a category itself can be regarded as a sort of general­ ized monoid. Chapters VI and VII explore this notion and its generaliza­ tions. Its close connection to pairs of adjoint functors illuminates the ideas of universal algebra and culminates in Beck's theorem characterizing categories of algebras; on the other hand, categories with a monoidal structure lead inter alia to the study of more convenient categories of topological spaces. (shrink)

Although the compound adjective ‘psychosocial’ was first used by academic psychologists in the 1890s, it was only in the interwar period that psychiatrists, psychologists and social workers began to develop detailed models of the psychosocial domain. These models marked a significant departure from earlier ideas of the relationship between society and human nature. Whereas Freudians and Darwinians had described an antagonistic relationship between biological instincts and social forces, interwar authors insisted that individual personality was made possible through collective organization. This (...) argument was advanced by dissenting psychoanalysts such as Ian Suttie and Karen Horney; biologists including Julian Huxley and Hans Selye; philosophers (e.g. Olaf Stapledon), anthropologists (e.g. Margaret Mead) and physicians (e.g John Ryle and James Halliday). This introduction and the essays that follow sketch out the emergence of the psycho-social by examining the methods, tools and concepts through which it was articulated. New statistical technologies and physiological theories allowed individual pathology to be read as an index of broader social problems and placed medical expertise at the centre of new political programmes. In these arguments the intangible structure of social relationships was made visible and provided a template for the development of healthy and effective forms of social organization. By examining the range of techniques deployed in the construction of the psychosocial (from surveys of civilian neurosis, techniques of family observation through to animal models of psychotic breakdown) a critical genealogy of the biopolitical basis of modern society is developed. (shrink)

The Everett interpretation of quantum mechanics divides naturally into two parts: first, the interpretation of the structure of the quantum state, in terms of branching, and second, the interpretation of this branching structure in terms of probability. This is the first of two reviews of the Everett interpretation, and focuses on structure, with particular attention to the role of decoherence theory. Written in terms of the quantum histories formalism, decoherence theory just is the theory of branching structure, in Everett's sense.

The Politics is one of the most influential texts in the history of political thought, and it raises issues which still confront anyone who wants to think seriously about the ways in which human societies are organized and governed. The work of one of the world's greatest philosophers, it draws on Aristotle's own great knowledge of the political and constitutional affairs of the Greek cities. By examining the way societies are run - from households to city states - Aristotle establishes (...) how successful constitutions can best be initiated and upheld. For this edition Sir Ernest Barker's fine translation, which has been widely used for nearly half a century, has been extensively revised to meet the needs of the modern reader. The accessible introduction and clear notes by R F Stalley examine the historical and philosophical background of the work and discuss its significance for modern political thought. (shrink)

The Everett interpretation of quantum mechanics divides naturally into two parts: first, the interpretation of the structure of the quantum state, in terms of branching, and second, the interpretation of this branching structure in terms of probability. This is the second of two reviews of the Everett interpretation, and focuses on probability. Branching processes are identified as chance processes, and the squares of branch amplitudes are chances. Since branching is emergent, physical probability is emergent as well.

Particle indistinguishability has always been considered a purely quantum mechanical concept. In parallel, indistinguishable particles have been thought to be entities that are not properly speaking objects at all. I argue, to the contrary, that the concept can equally be applied to classical particles, and that in either case particles may (with certain exceptions) be counted as objects even though they are indistinguishable. The exceptions are elementary bosons (for example photons).

This is a self-contained introduction to the Everett interpretation of quantum mechanics. It is the introductory chapter of Many Worlds? Everett, quantum theory, and reality, S. Saunders, J. Barrett, A. Kent, and D. Wallace, Oxford University Press.

A variety of ideas arising in decoherence theory, and in the ongoing debate over Everett's relative-state theory, can be linked to issues in relativity theory and the philosophy of time, specifically the relational theory of tense and of identity over time. These have been systematically presented in companion papers (Saunders 1995; 1996a); in what follows we shall consider the same circle of ideas, but specifically in relation to the interpretation of probability, and its identification with relations in the Hilbert (...) Space norm. The familiar objection that Everett's approach yields probabilities different from quantum mechanics is easily dealt with. The more fundamental question is how to interpret these probabilities consistent with the relational theory of change, and the relational theory of identity over time. I shall show that the relational theory needs nothing more than the physical, minimal criterion of identity as defined by Everett's theory, and that this can be transparently interpreted in terms of the ordinary notion of the chance occurrence of an event, as witnessed in the present. It is in this sense that the theory has empirical content. (shrink)

Authorship has proven a magnetic topic for literary studies and is now identified as an index of the current state of literary history and theory. The significance of this topic stems from a characteristic that literary criticism shared with the other human sciences: its drive to adopt a reflexive and self-critical posture towards its own central objects and concepts. By reflecting on authorship, criticism aspires not just to describe a literary phenomenon; it also wishes to bring to light the conditions (...) that make this phenomenon possible and thinkable.At the heart of recent studies of authorship, no matter how historical their aspiration, we find a certain quasi-philosophical dialectic or play between authorship and its material conditions, between the author as an exemplary consciousness and the unconscious determinations that bring this consciousness into being and speak through it. The thematic name for this play is the ‘formation of the subject.’. Our purpose is to provide a historical and theoretical argument against this conception of authorship and to outline an alternative approach. David Saunders and Ian Hunter teach in the Division of the Humanities, Griffith University, in Brisbane, Australia. Saunders is the author of Law and Authorship , and is coauthor with Hunter and Dugald Williamson of Book Sex: Obscenity Law and the Policing of Pornography . Hunter is the author of Culture and Government: The Emergence of Literary Education . His current project is a study of aesthetics as an ethos or way of life. (shrink)

The spread of vaccine misinformation may contribute to vaccine refusal/hesitancy and consequent harms. Nonetheless, censorship is often rejected on the grounds of free expression. This article examines John Stuart Mill’s influential defence of free expression but finds that his arguments for freedom apply only to normal, reasonably favourable circumstances. In other cases, it may be permissible to restrict freedom, including freedom of speech. Thus, while Mill would ordinarily defend the right to express false views, such as that vaccines cause autism, (...) he might have accepted restrictions on anti-vaccine misinformation during the present pandemic. This illustrates that even the staunchest defenders of free speech can permit temporary restrictions in exceptional circumstances. (shrink)

In this review of the Korean cloning scandal involving Woo-Suk Hwang, the nature of the disaster is documented and reasons why it occurred are suggested. The general problems it raises for scientific research are highlighted and six possible ways of improving practice are offered in the light of this case: better education of science students; independent monitoring and validation; guidelines for tissue donation for research; fostering of debate about ethically contentious research in science journals; development of an international code of (...) ethical research practice; fostering of public involvement in ethical review and debate through the web. (shrink)

The question of whether or not early Chinese philosophers had a concept of truth has been the topic of some scholarly debate over the past few decades. The present essay offers a novel assessment of the debate, and suggests that no answer is fully satisfactory, as the plausibility of each turns in no small part on difficult and unsettled philosophical issues prior to the interpretation of any ancient Chinese philosophical texts—particularly the issues of what it means to “have a concept” (...) and how we understand the concept of truth itself. This essay summarizes prominent views within the debate over truth and Chinese philosophy and offers conditional assessments of each answer with respect to contemporary theories of concepts and theories of truth. The essay concludes with an appeal to methodological and interpretive pluralism, within reasonable constraints, in discussions of this topic. (shrink)

Freedom lies at the heart of Kant’s philosophy. Three recent edited collections explore this key idea in different ways, alongside other related concep...

The concept of indistinguishable particles in quantum theory is fundamental to questions of ontology. All ordinary matter is made of electrons, protons, neutrons, and photons and they are all indistinguishable particles. Yet the concept itself has proved elusive, in part because of the interpretational difficulties that afflict quantum theory quite generally, and in part because the concept was so central to the discovery of the quantum itself, by Planck in 1900; it came encumbered with revolution. I offer a deflationary reading (...) of the concept ‘indistinguishable’ that is identical to Gibbs’ concept ‘generic phase’, save that it is defined for state spaces with only finitely-many states of bounded volume and energy. That, and that alone, makes for the difference between the quantum and Gibbs concepts of indistinguishability. This claim is heretical on several counts, but here we consider only the content of the claim itself, and its bearing on the early history of quantum theory rather than in relation to contemporary debates about particle indistinguishability and permutation symmetry. It powerfully illuminates that history. (shrink)

The article considers structuralism as a philosophy of mathematics, as based on the commonly accepted explicit mathematical concept of a structure. Such a structure consists of a set with specified functions and relations satisfying specified axioms, which describe the type of the structure. Examples of such structures such as groups and spaces, are described. The viewpoint is now dominant in organizing much of mathematics, but does not cover all mathematics, in particular most applications. It does not explain why certain structures (...) are dominant, not why the same mathematical structure can have so many different and protean realizations. ‘structure’ is just one part of the full situation, which must somehow connect the ideal structures with their varied examples. (shrink)

It is widely accepted that the notion of an inertial frame is central to Newtonian mechanics and that the correct space-time structure underlying Newton’s methods in Principia is neo-Newtonian or Galilean space-time. I argue to the contrary that inertial frames are not needed in Newton’s theory of motion, and that the right space-time structure for Newton’s Principia requires the notion of parallelism of spatial directions at different times and nothing more. Only relative motions are definable in this framework, never absolute (...) ones. (shrink)

But this picture of a ‘block universe’, composed of a timeless web of ‘world-lines’ in a four-dimensional space, however strongly suggested by the theory of relativity, is a piece of gratuitous metaphysics. Since the concept of change, of something happening, is an inseparable component of the common-sense concept of time and a necessary component of the scientist's view of reality, it is quite out of the question that theoretical physics should require us to hold the Eleatic view that nothing happens (...) in ‘the objective world’. Here, as so often in the philosophy of science, a useful limitation in the form of representation is mistaken for a deficiency of the universe. (shrink)

In this paper, we draw attention to several important tensions between Kant’s account of moral education and his commitment to transcendental idealism. Our main claim is that, in locating freedom outside of space and time, transcendental idealism makes it difficult for Kant to both provide an explanation of how moral education occurs, but also to confirm that his own account actually works. Having laid out these problems, we then offer a response on Kant’s behalf. We argue that, while it might (...) look like Kant has to abandon his commitment to either moral education or transcendental idealism, there is a way in which he can maintain both. (shrink)

It is shown that the Hilbert-Bernays-Quine principle of identity of indiscernibles applies uniformly to all the contentious cases of symmetries in physics, including permutation symmetry in classical and quantum mechanics. It follows that there is no special problem with the notion of objecthood in physics. Leibniz's principle of sufficient reason is considered as well; this too applies uniformly. But given the new principle of identity, it no longer implies that space, or atoms, are unreal.

The three most common responses to Taurek’s ‘numbers problem’ are saving the greater number, equal chance lotteries and weighted lotteries. Weighted lotteries have perhaps received the least support, having been criticized by Scanlon What We Owe to Each Other ( 1998 ) and Hirose ‘Fairness in Life and Death Cases’ ( 2007 ). This article considers these objections in turn, and argues that they do not succeed in refuting the fairness of a weighted lottery, which remains a potential solution to (...) cases of conflict. Moreover, it shows how these responses actually lead to a new argument for weighted lotteries, appealing to fairness and Pareto-optimality. (shrink)

Divine Action and Modern Science considers the relationship between the natural sciences and the concept of God acting in the world. Nicholas Saunders examines the Biblical motivations for asserting a continuing notion of divine action and identifies several different theological approaches to the problem. He considers their theoretical relationships with the laws of nature, indeterminism, and probabilistic causation. His book then embarks on a radical critique of current attempts to reconcile special divine action with quantum theory, chaos theory and (...) quantum chaos. As well as considering the implications of these problems for common interpretations of divine action, Saunders also surveys and codifies the many different theological, philosophical and scientific responses to divine action. The conclusion reached is that we are still far from a satisfactory account of how God might act in a manner that is consonant with modern science despite the copious recent scholarship in this area. (shrink)

Ces études débordent le problème du temps chez les Stoïciens et se proposent d’établir que cette question, en apparence modeste, permet d’éclairer, et en même temps commande l’ensemble du système.Au premier abord en effet, la théorie du temps se présente comme une simple section d’un chapitre de la Physique, celui qui traite des Incorporels. Mais déjà la simple interprétation des textes transmis fait voir que cette théorie tient étroitement à d’autres théories, comme celle des incorporels en général, des catégories, de (...) la substance. Abordant ensuite les thèses majeures de la logique et de l’éthique, on s’aperçoit qu’à leur tour elles sont solidaires de la conception du temps qui, dans bien des cas, fait évanouir leur apparence de paradoxe. A cela même, il n’y a rien d’étrange, si l’on se souvient que le stoïcisme, plus que tout autre philosophie antique, constitue un système cohérent. Mais plus particulièrement, le problème du temps a dû former comme le noeud de la réflexion stoïcienne qui vise, contre les lourdes autorités de Platon et d’Aristote, à rétablir dans sa réalité et dans sa dignité, le concret, le sensible, disqualifié comme « sujet à la génération et à la corruption », c’est-à-dire, en un mot, comme « l’être dans le temps ». (shrink)

Following Lewis, it is widely held that branching worlds differ in important ways from diverging worlds. There is, however, a simple and natural semantics under which ordinary sentences uttered in branching worlds have much the same truth values as they conventionally have in diverging worlds. Under this semantics, whether branching or diverging, speakers cannot say in advance which branch or world is theirs. They are uncertain as to the outcome. This same semantics ensures the truth of utterances typically made about (...) quantum mechanical contingencies, including statements of uncertainty, if the Everett interpretation of quantum mechanics is true. The ‘incoherence problem’ of the Everett interpretation, that it can give no meaning to the notion of uncertainty, is thereby solved. IntroductionMetaphysicsPersonal fissionBranching worldsPhysicsObjections. (shrink)

Until relatively recently, few democrats had much to say about the constitution of the ‘demos' that ought to rule. A number of recent writers have, however, argued that all those whose interests are affected must be enfranchised if decision-making is to be fully democratic. This article criticizes this approach, arguing that it misunderstands democracy. Democratic procedures are about the agency of the people so only agents can be enfranchised, yet not all bearers of interests are also agents. If we focus (...) on agency, rather than who is affected, then this leads us to focus on the permissible limits of action, rather than who makes the decision. Just as individual sovereignty is ordinarily limited by the requirement not to injure others, we may apply similar restrictions to what a demos can permissibly do. Thus, any collection of individuals may choose to regulate their affairs collectively for mutual benefit, but should be prohibited from imposing negative externalities on outsiders. On this view, the constitution or definition of the demos is arbitrary, from the democratic point of view. Moreover, democracy does not require the expansion of the franchise, unless injuries cannot be avoided. (shrink)

Proposals for increasing organ donation are often rejected as incompatible with altruistic motivation on the part of donors. This paper questions, on conceptual grounds, whether most organ donors really are altruistic. If we distinguish between altruism and solidarity – a more restricted form of other-concern, limited to members of a particular group – then most organ donors exhibit solidarity, rather than altruism. If organ donation really must be altruistic, then we have reasons to worry about the motives of existing donors. (...) However, I argue that altruism is not necessary, because organ donation supplies important goods, whatever the motivation, and we can reject certain dubious motivations, such as financial profit, without insisting on altruism.Once solidaristic donation is accepted, certain reforms for increasing donation rates seem permissible. This paper considers two proposals. Firstly, it has been suggested that registered donors should receive priority for transplants. While this proposal appears based on a solidaristic norm of reciprocity, it is argued that such a scheme would be undesirable, since non-donors may contribute to society in other ways. The second proposal is that donors should be able to direct their organs towards recipients that they feel solidarity with. This is often held to be inconsistent with altruistic motivation, but most donation is not entirely undirected in the first place (for instance, donor organs usually go to co-nationals). While allowing directed donation would create a number of practical problems, such as preventing discrimination, there appears to be no reason in principle to reject it. (shrink)

Douglas Diekema influentially argues that interference with parental decisions is not in fact guided by the child’s best interests, but rather by a more permissive standard, which he calls the harm principle. This article first seeks to clarify this alternative position and defend it against certain existing criticisms, before offering a new criticism and alternative. This ‘harm principle’ has been criticized for (i) lack of adequate moral grounding, and (ii) being as indeterminate as the best interest standard that it seeks (...) to replace. I argue that these are not serious problems. I take Diekema’s negative point to be right—our actual standard for intervention is not literally the best interests of the child—but I disagree with his proposed replacement. First, Diekema’s proposed harm threshold should be more carefully distinguished from Mill’s harm principle. Second, there is no reason to assume that the standard for permissible intervention coincides with the threshold for harm (or serious harm). Thus, I propose that the best alternative to the best interests standard is not a harm principle, but rather a sufficiency threshold between adequate (or ‘good enough’) and inadequate (or ‘substandard’) parenting. (shrink)

In this chapter, we compare Kant and James’ accounts of freedom. Despite both thinkers’ rejecting compatibilism for the sake of practical reason, there are two striking differences in their stances. The first concerns whether or not freedom requires the possibility of an open future. James holds that morality hinges on the real possibility that the future can be affected by our actions. Kant, on the other hand, seems to maintain that we can still be free in the crucial sense, even (...) if none of our actions can have any effect on the future. The second difference between them is related, and concerns the location of freedom. Kant views experience as determined by natural necessity, and locates freedom outside of it, in things-in-themselves. James, on the other hand, has a richer conception of experience than Kant, and holds that we can locate our freedom within experience alone. In the end, we contend that James has a better account of how freedom relates to our experience, but this comes at a cost. For while Kant's account struggles with the relationship between freedom and experience, it has the advantage of insulating our freedom from potential empirical challenges. (shrink)

One way of increasing the supply of organs available for transplant would be to switch to an opt-out system of donor registration. This is typically assumed to operate on the basis of presumed consent, but this faces the objection that not all of those who fail to opt out would actually consent to the use of their cadaveric organs. This paper defuses this objection, arguing that people's actual, explicit or implicit, consent to use their organs is not needed. It borrows (...) David Estlund's notion of ‘normative consent’ from the justification of political authority and applies it to the case of organ donation. According to this idea, when it is wrong to withhold consent to something, the moral force of that lack of consent may be null and void. If it is wrong of a person to refuse to donate their cadaveric organs to others, then it may be that their actual consent is not needed. This supports an opt-out system, which provides protection for those who have genuine reasons to refuse donation, and spares the worries as to what the deceased would actually have wanted. (shrink)