Artificial intelligence research has foundered on the issue of representation. When intelligence is approached in an incremental manner, with strict reliance on interfacing to the real world through perception and action, reliance on representation disappears. In this paper we outline our approach to incrementally building complete intelligent Creatures. The fundamental decomposition of the intelligent system is not into independent information processing units which must interface with each other via representations. Instead, the intelligent system is decomposed into independent and parallel activity (...) producers which all interface directly to the world through perception and action, rather than interface to each other particularly much. The notions of central and peripheral systems evaporateeverything is both central and peripheral. Based on these principles we have built a very successful series of mobile robots which operate without supervision as Creatures in standard office environments. (shrink)

Comprehensive account of constructive theory of first-order predicate calculus. Covers formal methods including algorithms and epi-theory, brief treatment of Markov’s approach to algorithms, elementary facts about lattices and similar algebraic systems, more. Philosophical and reflective as well as mathematical. Graduate-level course. 1963 ed. Exercises.

CHAPTER Addenda to Pure Combinatory Logic This chapter will treat various additions to, and modifications of, the subject matter of Chapters-7. ...

Despite its pervasiveness, the concept of ‘levels of organization’ has received relatively little attention in its own right. I propose here an emerging approach that posits ‘levels’ as a fragmentary concept situated within an interest-relative matrix of operational usage within scientific practice. To this end I propose one important component of meaning, namely the epistemic goal motivating the term’s usage, which recovers a remarkably conserved and sufficiently unifying significance attributable to ‘levels’ across different instances of usage. This epistemic goal, to (...) provide structure to scientific problems, delegates tasks whose execution generates the term’s expressed content in a given instance. This treatment of levels does not diminish the concept’s general importance to science, but rather allows for its use in, and usefulness for, scientific practice to be better contextualized to particular tasks encompassing varying breadths of activity. (shrink)

Despite the ubiquity of “levels of organization” in the scientific literature, a nascent “levels skepticism” now claims that the concept of levels is an inherently flawed, misleading, or otherwise inadequate notion for understanding how life scientists produce knowledge about the natural world. However, levels skeptics rely on the maligned “layer-cake” account of levels stemming from Oppenheim and Putnam’s defense of the unity of science for their critical commentary. Recourse to layer-cake levels is understandable, as it is arguably the default conception (...) of levels in philosophy. However, relying on this conception of levels undermines the initial plausibility of general dismissals of the concept, because the problems skeptics identify within the “basic idea” of the concept “levels” are merely ones already widely acknowledged in this conception. I illustrate this “guilt by association” by looking at the embedded role of “levels” in articulating intertheoretical reductionism during the latter part of the 20th century. I conclude by suggesting a methodological framework focusing on local usage patterns as a promising means for future analysis of the levels concept. (shrink)

The concept of 'levels of organization' has come under fire recently as being useless for scientific and philosophical purposes. In this paper, we show that 'levels' is actually a remarkably resilient and constructive conceptual tool that can be, and in fact is, used for a variety of purposes. To this effect, we articulate an account of the importance of the levels concept seen in light of its status as a major organizing concept of biology. We argue that the usefulness of (...) ‘levels’ is best seen in the heuristic contributions the concept makes to treating and structuring scientific problems. We illustrate this with two examples from biological research. (shrink)

The majority of North American corporations awakened to the need for their own ethical guidelines during the late 1970s and early 1980s, even though modern corporations are subject to a surprising multiplicity of external codes of ethics or conduct. This paper provides an understanding of both internal and external codes through a discussion of the factors behind the development of the codes, an analysis of internal codes and an identification of problems with them.

Corporate sustainability introduces multiple tensions or paradoxes into organisations which defy traditional approaches such as trading-off contrasting options. We examine an alternative approach: to manage corporate sustainability with a paradoxical lens where contradictory elements are managed concurrently. Drawing on paradox theory, we focus on two specific pathways: to the organisation-wide acceptance of paradox and to paradoxical resolution. Introducing the concept of strategic agility, we argue that strategically agile organisations are better placed to navigate these paradox pathways. Strategic agility comprises three (...) organisational meta-capabilities: strategic sensitivity, collective commitment, and resource fluidity. We propose that strategically agile organisations draw on strategic sensitivity and collective commitment to achieve organisation-wide acceptance of paradox, and collective commitment and resource fluidity to achieve paradoxical resolution. For each of these meta-capabilities, we identify three organisational practices and processes specifically related to corporate sustainability that organisations can leverage in pursuit of strategic agility. We offer a conceptual framework depicting the strategic agility meta-capabilities, and associated practices and processes, which organisations draw on to successfully manage corporate sustainability with a paradoxical lens. (shrink)

Exploring the use of nudges and informed consent in medical ethics.

The future of philosophy is moving towards “global philosophy.” The idea of global philosophy is the view that different philosophical approaches may engage more substantially with each other to solve philosophical problems. Most solutions attempt to use only those available resources located within one philosophical tradition. A more promising approach might be to expand the range of available resources to better assist our ability to offer more compelling solutions. This search for new horizons in order to improve our clarity about (...) philosophical issues is at the heart of global philosophy. The idea of global philosophy encourages us to look beyond our traditions to improve our philosophical problem-solving by our own lights. Global philosophy is a new approach whose time is coming. This essay offers the first account of this approach and an assessment of its future promise. (shrink)

People frequently gesture when problem-solving, particularly on tasks that require spatial transformation. Gesture often facilitates task performance by interacting with internal mental representations, but how this process works is not well understood. We investigated this question by exploring the case of mental abacus, a technique in which users not only imagine moving beads on an abacus to compute sums, but also produce movements in gestures that accompany the calculations. Because the content of MA is transparent and readily manipulated, the task (...) offers a unique window onto how gestures interface with mental representations. We find that the size and number of MA gestures reflect the length and difficulty of math problems. Also, by selectively interfering with aspects of gesture, we find that participants perform significantly worse on MA under motor interference, but that perceptual feedback is not critical for success on the task. We conclude that premotor processes involved in the planning of gestures are critical to mental representation in MA. (shrink)

Integrating concepts of maintenance and of origins is essential to explaining biological diversity. The unified theory of evolution attempts to find a common theme linking production rules inherent in biological systems, explaining the origin of biological order as a manifestation of the flow of energy and the flow of information on various spatial and temporal scales, with the recognition that natural selection is an evolutionarily relevant process. Biological systems persist in space and time by transfor ming energy from one state (...) to another in a manner that generates structures which allows the system to continue to persist. Two classes of energetic transformations allow this; heat-generating transformations, resulting in a net loss of energy from the system, and conservative transformations, changing unusable energy into states that can be stored and used subsequently. All conservative transformations in biological systems are coupled with heat-generating transformations; hence, inherent biological production, or genealogical proesses, is positively entropic. There is a self-organizing phenomenology common to genealogical phenomena, which imparts an arrow of time to biological systems. Natural selection, which by itself is time-reversible, contributes to the organization of the self-organized genealogical trajectories. The interplay of genealogical (diversity-promoting) and selective (diversity-limiting) processes produces biological order to which the primary contribution is genealogical history. Dynamic changes occuring on times scales shorter than speciation rates are microevolutionary; those occuring on time scales longer than speciation rates are macroevolutionary. Macroevolutionary processes are neither redicible to, nor autonomous from, microevolutionary processes. (shrink)

Conditional cash transfers represent an innovation in social assistance policy by conditioning welfare benefits on recipients’ behaviors associated with human capital development. Although social assistance has expanded throughout the developing world in the 21st century, the political logic guiding CCT adoption differs sharply from that of unconditional cash transfers, and from the politics of social insurance development. Striking spatial and temporal correlations in their adoption also raise the specter of policy interdependence. A dynamic logit analysis of social assistance reforms in (...) developing nations from 1990 to 2011 reveals that although CCTs have been impelled by democratization in developing countries, the model is not embraced systematically by the left or the right of the political spectrum. Rather, CCTs are more likely to be adopted in contexts of divided government and where regional neighbors, and more democratic countries in the region, have previously adopted them. (shrink)

This volume is the direct result of a conference in which a number of leading researchers from the fields of artificial intelligence and biology gathered to ...

The causal exclusion argument suggests that mental causes are excluded in favour of the underlying physical causes that do all the causal work. Recently, a debate has emerged concerning the possibility of avoiding this conclusion by adopting Woodward's interventionist theory of causation. Both proponents and opponents of the interventionist solution crucially rely on the notion of supervenience when formulating their positions. In this article, we consider the relation between interventionism and supervenience in detail and argue that importing supervenience relations into (...) the interventionist framework is deeply problematic. However, rather than reject interventionist solutions to exclusion wholesale, we wish to propose that the problem lies with the concept of supervenience. This would open the door for a moderate defence of the interventionist solution to the exclusion argument. (shrink)

In both Great Britain and the United States there has been a growing debate about the modern acceptability of jury nullification. Properly understood, juries do not have any constitutional right to ignore the law, but they do have the power to do so nevertheless. Juries that nullify may be motivated by a variety of concerns: too harsh sentences, improper government action, racism, etc. In this article, I shall attempt to defend jury nullification on a number of grounds. First, I discuss (...) the use of general verdicts and reject their replacement in criminal trials by special verdicts. Second, I examine verdicts based upon mistakes and racial prejudice, turning my attention to perverse verdicts and the question of whether or not juries are guilty of legislating when nullifying the law. Finally, I look at the problem of the awarding of excessive damages by juries. My goal will be to provide a sound theoretical defence of the practice of jury nullification. (shrink)

boundaries. It is impossible to do good science without having an appreciation for the problems and concepts in the other levels of abstraction (at least in the direction from biology towards physics), but there are whole sets of tools, methods of analysis, theories and explanations within each discipline which do not cross those boundaries.

This article offers a justification for the continued use of jury trials. I shall critically examine the ability of juries to render just verdicts, judicial impartiality, and judicial transparency. My contention is that the judicial system that best satisfies these values is most preferable. Of course, these three values are not the only factors relevant for consideration. Empirical evidence demonstrates that juries foster both democratic participation and public legitimation of legal decisions regarding the most serious cases. Nevertheless, juries are costly (...) and, therefore, economically less efficient than competing modes of trial. I do not argue that all human beings possess an inalienable legal right to be tried by a jury. However, it is my hope that this analysis will make clear what we might gain or lose when we propose jury reforms. (shrink)

Polygamy is a hotly contested practice and open to widespread misunderstandings. This practice is defined as a relationship between either one husband and multiple wives or one wife and multiple husbands. Today, “polygamy” almost exclusively takes the form of one husband with multiple wives. In this article, my focus will center on limited defenses of polygamy offered recently by Chesire Calhoun and Martha Nussbaum. I will argue that these defenses are unconvincing. The problem with polygamy is primarily that it is (...) a structurally inegalitarian practice in both theory and fact. Polygamy should be opposed for this reason. (shrink)

Tool use is a central topic in research on cognitive evolution and behavioral ecology in non-human animals. Originally thought to be a uniquely human phenomenon, many other species have been observed making and using tools for a variety of purposes, starting with Goodall’s groundbreaking work with chimpanzees in Gombe. Despite the frequent attention and great research interest in animal tool use, and ubiquity of the behavior, we argue here that chewing sticks by dogs should be included as a case of (...) tool use. We discuss alternate possible explanations and then propose several testable predictions regarding this hypothesis. We suggest that tool use may be more common than is often assumed and that many cases of animal tool use may be overlooked. (shrink)

This article argues that even if we grant that murderers may deserve death in principle, retributivists should still oppose capital punishment. The reason? Our inability to know with certainty whether or not individuals possess the necessary level of desert. In large part due to advances in science, we can only be sure that no matter how well the trial is administered or how many appeals are allowed or how many years we let elapse, we will continue to execute innocent persons (...) for as long as we legalize capital punishment. Thus, on grounds of desert, this article argues that retributivists should oppose capital punishment. (shrink)

Most philosophers reject what we might call "penal pluralism": the idea that punishment can and should encompass multiple penal goals or principles. This is rejected because it is often held that different penal goals or principles will conflict: the goal of punishing an offender to the degree deserved may differ and even undermine the goal of enabling deterrence or rehabilitation. For this reason, most philosophers argue that we must make a choice, such as choosing between retribution and its alternatives. In (...) "Some Remarks on Punishment," F. H. Bradley re-examines the justification of punishment in light of a critique of Darwinism's importance for ethics. My primary focus is on how Bradley's substantive discussion of punishment only because it is here that this article's arguments have most relevance for us today. (shrink)

Recent work on epistemic integration in the life sciences has emphasized the importance of integration in thinking about explanatory practice in science, particularly for articulating a robust alternative to reductionism and anti-reductionism. This paper analyzes the role of models in balancing the relative contributions of lower- and higher-level epistemic resources involved in this process. Integration between multiple disciplines proceeds by constructing a problem agenda (Love 2008), a set of interrelated problems that structures the problem space of a complex phenomenon that (...) is investigated by many disciplines. The usage of models, it is argued, mark changes in a phenomenon’s problem agenda depending on the task that is expected of it. Particularly, it emphasizes the sensitivity of a problem agenda to changing attitudes in the solutions to the conceptual and empirical items constituting that agenda. The analysis will proceed by means of a case study, the Reichardt motion detector, a model that has been vital to the methodological and conceptual development of research on motion detection, especially in invertebrates. As will be seen, the history of the Reichardt model will exemplify the dynamic changes that occur in the interdisciplinary negotiations that comprise the active efforts of various sciences working to integrate their resources. (shrink)

Hegel’s project of reconciliation is central to his Philosophy of Right. This article argues that scholars have understood this project in one of two ways, as a form of rational reconciliation or a kind of endorsement. Each is incomplete and their inability to capture the kind of reconciliation Hegel has in mind is made apparent when we consider the kind of problem that the rabble creates for modern society, which reconciliation is meant to address. The article concludes that more than (...) mutual recognition is required and we should recognise the crucial role played by stakeholding, whereby citizens share a principled conviction about oneself and others. (shrink)

-/- Amongst contemporary theorists, the most widespread interpretation of Hegel's theory of punishment is that it is a retributivist theory of annulment, where punishments cancel the performance of crimes. The theory is retributivist insofar as the criminal punished must be demonstrated to be deserving of a punishment that is commensurable in value only to the nature of his crime, rather than to any consequentialist considerations. As Antony Duff says: -/- [retributivism] justifies punishment in terms not of its contingently beneficial effects (...) but of its intrinsic justice as a response to crime; the justificatory relationship holds between present punishment and past crime, not between present punishment and future effects. -/- Punishment is given only to persons responsible for committing crime. In addition, the degree of punishment is set in proportion to the relative badness of the precipitating crime. Thus, retributivism can be understood as an individualistic theory because the only relevant factors pertain solely to the individual criminal himself. -/- The general attraction of Hegel's version of retributivism is that the punishments his theory is thought to endorse are commensurable in value with precipitating crimes, in contrast to the strict equivalence required by Kant's theory of punishment. As a result, Hegel's theory is praised both for being more acceptable to modern readers than Kant's so-called ‘pure retributivism’, as well as for being an ‘emphatically anti-utilitarian’ theory. Despite widespread agreement on these general features, it is hotly contested how exactly we are to understand the way in which punishment cancels crimes, and Hegel's difficult style has only served to make the controversy deeper. For example, Ted Honderich says: ‘A punishment is an annulment, a cancellation or a return to a previous state of affairs … All this, of course, is obscure. It is by Hegel’. (shrink)

My book, Punishment, has three aims: to provide the most comprehensive and updated examination of the philosophy of punishment available, to advance a new theory—the unified theory of punishment—as a compelling alternative to available theories and to consider the relation of theory to practice. In his recent review article, Mark Tunick raises several concerns with my analysis. I address each of these concerns and argue they rest largely on misinterpretations which I restate and clarify here.

abstract Shame punishments have become an increasingly popular alternative to traditional punishments, often taking the form of convicted criminals holding signs or sweeping streets with a toothbrush. In her Hiding from Humanity, Martha Nussbaum argues against the use of shame punishments because they contribute to an offender's loss of dignity. However, these concerns are shared already by the courts which also have concerns about the possibility that shaming might damage an offender's dignity. This situation has not led the courts to (...) reject all uses of shaming, but only to accept shaming within certain safeguards. Thus, despite Nussbaum's important reservations against shame punishments, it may still be possible for her to accept shaming within specific parameters such as those set out by the courts that protect the dignity of an offender. As a result, she need not be opposed to the use of legitimate shame punishment. (shrink)

John Rawls argues that A Theory of Justice suffers from a “serious problem”: the problem of political stability. His theory failed to account for the reality that citizens are deeply divided by reasonable and incompatible religious, philosophical, and moral comprehensive doctrines. This fact of reasonable pluralism may pose a threat to political stability over time and requires a solution. Rawls proposes the idea of an overlapping consensus among incompatible comprehensive doctrines through the use of public reasons in his later Political (...) Liberalism. -/- Rawls’s proposed solution to the problem of political stability has received much criticism. Some, such as Kurt Baier, Brian Barry, George Klosko, and Edward McClennen, argue that an overlapping consensus is relatively unnecessary. Rawls should have acknowledged existing resources in his account that might secure political stability over time without major changes to his original views about justice. Others, including Kent Greenawalt, Michael Sandel, Leif Wenar, and Iris Marion Young believe that an overlapping consensus is too fragile to secure political stability. Rawls correctly identifies a major problem for his original account, but he fails to provide a satisfactory solution. -/- I believe these objections rest on a mistake easily overlooked. Each objection claims that, for Rawls, the possibility of future political stability is to be guaranteed by an overlapping consensus alone. This perspective fails to recognize the central importance of the social minimum in securing political stability. There is, in fact, more resources to secure political stability than Rawls or his critics have recognized. -/- My discussion will begin with a brief explanation of why the problem of political stability raises an important challenge to Rawls’s views on justice and why he argues for an overlapping consensus as a solution to it. I will next consider the more important objections to Rawls’s solution and why these fail. I will argue that the social minimum might better support political stability if it is broadly understood in terms of the capabilities approach. This approach is compatible with Rawls’s political liberalism and it provides a more robust understanding of a just social minimum. Political stability does not rely upon an overlapping consensus alone — and it may be better secured where the capabilities approach plays a more central role. Therefore, Rawls does provide a illuminating solution to the problem of political stability that is more compelling if we incorporate the capabilities approach into political liberalism. (shrink)

Previous work has found that guiding problem-solvers' movements can have an immediate effect on their ability to solve a problem. Here we explore these processes in a learning paradigm. We ask whether guiding a learner's movements can have a delayed effect on learning, setting the stage for change that comes about only after instruction. Children were taught movements that were either relevant or irrelevant to solving mathematical equivalence problems and were told to produce the movements on a series of problems (...) before they received instruction in mathematical equivalence. Children in the relevant movement condition improved after instruction significantly more than children in the irrelevant movement condition, despite the fact that the children showed no improvement in their understanding of mathematical equivalence on a ratings task or on a paper-and-pencil test taken immediately after the movements but before instruction. Movements of the body can thus be used to sow the seeds of conceptual change. But those seeds do not necessarily come to fruition until after the learner has received explicit instruction in the concept, suggesting a “sleeper effect” of gesture on learning. (shrink)

Utilitarianism is commonly assumed to be the most appropriate sub-structure for medical ethics. This view is challenged. It is suggested that the utilitarian approach to euthanasia works against the patient's individual advantage and is a corrupting influence in the relationship between the physician and society. Dignity for the individual patient is not easily achieved by assessing that person's worth against the yardstick of others' needs and wishes.

Proponents of two axioms of biological evolutionary theory have attempted to find justification by reference to nonequilibrium thermodynamics. One states that biological systems and their evolutionary diversification are physically improbable states and transitions, resulting from a selective process; the other asserts that there is an historically constrained inherent directionality in evolutionary dynamics, independent of natural selection, which exerts a self-organizing influence. The first, the Axiom of Improbability, is shown to be nonhistorical and thus, for a theory of change through time, (...) acausal. Its perception of the improbability of living states is at least partially an artifact of closed system thinking. The second, the Axiom of Historically Determined Inherent Directionality, is supported evidentially and has an explicit historical component. Historically constrained dynamic populations are inherently nonequilibrium systems. It is argued that living, evolving systems, when considered to be historically constrained nonequilibrium systems, do not appear improbable at all. Thus, the two axioms are not compatible. Instead, the Axiom of Improbability is considered to result from an unjustified attempt to extend the contingent proximal actions of natural selection into the area of historical, causal explanations. It is thus denied axiomatic status, and the effects of natural selection are subsumed as an additional level of constraint in an evolutionary theory derived from the Axiom of Historically Determined Inherent Directionality. (shrink)

This study extends experimental tests of (cumulative) prospect theory (PT) over prospects with more than three outcomes and tests second-order stochastic dominance principles (Levy and Levy, Management Science 48:1334–1349, 2002; Baucells and Heukamp, Management Science 52:1409–1423, 2006). It considers choice behavior of people facing prospects of three different types: gain prospects (losing is not possible), loss prospects (gaining is not possible), and mixed prospects (both gaining and losing are possible). The data supports the distinction of risk behavior into these three (...) categories of prospects, Further, probability weighting and diminishing sensitivity of utility as predicted by PT are observed. Loss aversion is, however, less pronounced, except for choices where one prospect is degenerate. The data suggests that the probability of losing may be relevant for loss aversion. (shrink)

Restorative justice is highly promising as an effective approach to better supporting victims, reducing reoffending, and lowering costs. The challenge it faces is a dual hurdle of limited applicability and lack of public confidence. The issue is how we might better embed restorative justice in the criminal justice system so its promising effectiveness could be shared more widely while increasing public confidence. This chapter explores the new approach of punitive restoration, which gives more tools for restoration including a wider punitive (...) element. Its goal is to win support for greater use of restorative practices and a less punitive criminal justice system overall. (shrink)

This chapter contains sections titled: Background The Philosophy of Right : New Essays, New Insights Note Abbreviations References. -/- Hegel's Philosophy of Right presents a collection of new essays by leading international philosophers and Hegel scholars that analyze and explore Hegel's key contributions in the areas of ethics, politics, and the law. The most comprehensive collection on Hegel's Philosophy of Right available Features new essays by leading international Hegel interpreters divided in sections of ethics, politics, and law Presents significant new (...) research on Hegel's Philosophy of Right that will set a new standard for future work on the topic. (shrink)

This article argues political liberalism can and should be revised to improve its relevance to the private law. This approach is not a rejection of political liberalism, but instead a restatement consistent with the fundamental tenets of Rawls’s theory of justice. The first part begins with a brief summary of Rawls’s political liberalism. The second part discusses the strategies used to demonstrate the relevance of Rawls’s theory to the private law. The third part examines how Rawls’s theory can and should (...) be revised by incorporating capabilities. I argue this revision can be undertaken in a way that best develops the relevance of political liberalism. (shrink)

What is a crime? A common answer is that crimes are harms. One particular argument is that morality forms the connection between crimes and harms: crimes are not any kind of harm, but specifically a kind of immorality. This position is consistent with natural law jurisprudence which claims that law and morality are inseparably linked. It is also consistent with standard defences of retribution whereby punishment is justified where deserved and to the degree deserved. Retributivist desert is present for individuals (...) that possess some degree of moral responsibility for causing or attempting to cause evil. For example, the murderer deserves severe punishment because he is morally responsible for another person’s death and this act is sufficiently evil to warrant severe punishment. -/- The idea that crimes are harms to morals — and so their immorality informs their criminality and the corresponding severity of punishment — has also found favour with so-called ‘expressivist’ theories of punishment defended by Joel Feinberg, Antony Duff and others. These theories argue that punishment has an expressivist function of communication public disapproval to criminal offenders for their moral wrongdoings where punishment is proportionate to immorality. -/- The justification of crimes as harms to morals is part of a venerable tradition that has come to be increasingly seen as discredited. Most academics working in law (and even more practising lawyers) reject natural law jurisprudence and support some version of the separability thesis of legal positivism where law and morality are held to be separable, but not intrinsically and necessarily linked. Yet, curiously, retributivist theories, including expressivism, have been on the ascendency with a growing number of legal philosophers defending the idea of crimes as harms to morals and, therefore, moving in a contrary direction to most others working in law and academic law. -/- I believe this general position is deeply problematic and should be rejected. This chapter focuses specifically on expressivist theories as the increasingly more popular variant of retributivism in academic circles today. The next section provides an overview of expressivism. The following sections argue that it is not compelling both as a view about the criminal law, but also as a theory about punishment. I close the chapter with ideas about criminal harms might be better understood. I argue that crimes might be a kind of harm, but not the kinds of harm endorsed by retributivists and, more specifically, expressivists. (shrink)

I am very grateful to the contributors for this symposium for their essays on my Punishment book. Each focuses with different elements of my work. Antony Duff examines the definition of punishment in my first few pages. Michelle Madden Dempsey analyses the importance given to coherence in my account and critique of expressivist theories of punishment. Richard Lippke considers my statements about negative retributivism in an important new defence of that approach. I examine each of these in turn below. While (...) I do not change my position, they draw attention to certain features in my overall argument worth reflecting on at greater length. So I welcome this opportunity to address and clarify these now and grateful for their helping me to rethink my original arguments. (shrink)