Jonathan Y. Tsou examines and defends positions on central issues in philosophy of psychiatry. The positions defended assume a naturalistic and realist perspective and are framed against skeptical perspectives on biological psychiatry. Issues addressed include the reality of mental disorders; mechanistic and disease explanations of abnormal behavior; definitions of mental disorder; natural and artificial kinds in psychiatry; biological essentialism and the projectability of psychiatric categories; looping effects and the stability of mental disorders; psychiatric classification; and the validity of the (...) DSM's diagnostic categories. The main argument defended by Tsou is that genuine mental disorders are biological kinds with harmful effects. This argument opposes the dogma that mental disorders are necessarily diseases that result from biological dysfunction. Tsou contends that the broader ideal of biological kinds offers a more promising and empirically ascertainable naturalistic standard for assessing the reality of mental disorders and the validity of psychiatric categories. (shrink)

Many philosophers have been attracted to the view that reasons are premises of good reasoning – that reasons to φ are premises of good reasoning towards φ-ing. However, while this reasoning view is indeed attractive, it faces a problem accommodating outweighed reasons. In this article, I argue that the standard solution to this problem is unsuccessful and propose an alternative, which draws on the idea that good patterns of reasoning can be defeasible. I conclude by drawing out implications for the (...) debate over pragmatic reasons for belief and other attitudes and for one influential form of reductionism about the normative. (shrink)

Deep brain stimulation has been of considerable interest to bioethicists, in large part because of the effects that the intervention can occasionally have on central features of the recipient’s personality. These effects raise questions regarding the philosophical concept of authenticity. In this article, we expand on our earlier work on the concept of authenticity in the context of deep brain stimulation by developing a diachronic, value-based account of authenticity. Our account draws on both existentialist and essentialist approaches to authenticity, and (...) Laura Waddell Ekstrom’s coherentist approach to personal autonomy. In developing our account, we respond to Sven Nyholm and Elizabeth O’Neill’s synchronic approach to authenticity, and explain how the diachronic approach we defend can have practical utility, contrary to Alexandre Erler and Tony Hope’s criticism of autonomy-based approaches to authenticity. Having drawn a distinction between the authenticity of an individual’s traits and the authenticity of that person’s values, we consider how our conception of authenticity applies to the context of anorexia nervosa in comparison to other prominent accounts of authenticity. We conclude with some reflections on the prudential value of authenticity, and by highlighting how the language of authenticity can be invoked to justify covert forms of paternalism that run contrary to the value of individuality that seems to be at the heart of authenticity. (shrink)

Causal claims are context sensitive. According to the old orthodoxy (Mackie 1974, Lewis 1986, inter alia), the context sensitivity of causal claims is all due to conversational pragmatics. According to the new contextualists (Hitchcock 1996, Woodward 2003, Maslen 2004, Menzies 2004, Schaffer 2005, and Hall ms), at least some of the context sensitivity of causal claims is semantic in nature. I want to discuss the prospects for causal contextualism, by asking why causal claims are context sensitive, what they are sensitive (...) to, and where they are sensitive to it. (shrink)

Research on the capacity to understand others' minds has tended to focus on representations ofbeliefs,which are widely taken to be among the most central and basic theory of mind representations. Representations ofknowledge, by contrast, have received comparatively little attention and have often been understood as depending on prior representations of belief. After all, how could one represent someone as knowing something if one does not even represent them as believing it? Drawing on a wide range of methods across cognitive science, (...) we ask whether belief or knowledge is the more basic kind of representation. The evidence indicates that nonhuman primates attribute knowledge but not belief, that knowledge representations arise earlier in human development than belief representations, that the capacity to represent knowledge may remain intact in patient populations even when belief representation is disrupted, that knowledge (but not belief) attributions are likely automatic, and that explicit knowledge attributions are made more quickly than equivalent belief attributions. Critically, the theory of mind representations uncovered by these various methods exhibits a set of signature features clearly indicative of knowledge: they are not modality-specific, they are factive, they are not just true belief, and they allow for representations of egocentric ignorance. We argue that these signature features elucidate the primary function of knowledge representation: facilitating learning from others about the external world. This suggests a new way of understanding theory of mind – one that is focused on understanding others' minds in relation to the actual world, rather than independent from it. (shrink)

Many philosophers accept a response constraint on normative reasons: that p is a reason for you to φ only if you are able to φ for the reason that p. This constraint offers a natural way to cash out the familiar and intuitive thought that reasons must be able to guide us, and has been put to work as a premise in a range of influential arguments in ethics and epistemology. However, the constraint requires interpretation and faces putative counter-examples due (...) to Julia Markovits, Mark Schroeder, and others. This paper develops and motivates an interpretation of the response constraint that avoids the putative counter-examples. (shrink)

In this article, I argue that depression and suicide are natural kinds insofar as they are classes of abnormal behavior underwritten by sets of stable biological mechanisms. In particular, depression and suicide are neurobiological kinds characterized by disturbances in serotonin functioning that affect various brain areas (i.e., the amygdala, anterior cingulate, prefrontal cortex, and hippocampus). The significance of this argument is that the natural (biological) basis of depression and suicide allows for reliable projectable inferences (i.e., predictions) to be made about (...) individual members of a kind. In the context of assisted suicide, inferences about the decision-making capacity of depressed individuals seeking physician-assisted suicide are of special interest. I examine evidence that depression can hamper the decision-making capacity of individuals seeking assisted suicide and discuss some implications. (shrink)

In this paper, we claim that, if you justifiably believe that you ought to perform some act, it follows that you ought to perform that act. In the first half, we argue for this claim by reflection on what makes for correct reasoning from beliefs about what you ought to do. In the second half, we consider a number of objections to this argument and its conclusion. In doing so, we arrive at another argument for the view that justified beliefs (...) about what you ought to do must be true, based in part on the idea that the epistemic and practical domains are uniform, in a sense we spell out. We conclude by sketching possible implications of our discussion for the debates over what is wrong with akrasia and pragmatic encroachment on justified belief and knowledge. (shrink)

This article gives an overview of some recent debates about the relationship between reasons and rational requirements of coherence - e.g. the requirements to be consistent in our beliefs and intentions, and to intend what we take to be the necessary means to our ends.

Evidentialism is the thesis that all reasons to believe p are evidence for p. Pragmatists hold that pragmatic considerations – incentives for believing – can also be reasons to believe. Nishi Shah, Thomas Kelly and others have argued for evidentialism on the grounds that incentives for belief fail a ‘reasoning constraint’ on reasons: roughly, reasons must be considerations we can reason from, but we cannot reason from incentives to belief. In the first half of the paper, I show that this (...) argument fails: the claim that we cannot reason from incentives is either false or does not combine with the reasoning constraint to support evidentialism. However, the failure of this argument suggests an alternative route to evidentialism. Roughly, reasons must be premises of good reasoning, but it is not good reasoning to reason from incentives to belief. The second half of the paper develops and defends this argument for evidentialism. (shrink)

A large part of the controversy surrounding the publication of DSM-5 stems from the possibility of replacing the purely descriptive approach to classification favored by the DSM since 1980. This paper examines the question of how mental disorders should be classified, focusing on the issue of whether the DSM should adopt a purely descriptive or theoretical approach. I argue that the DSM should replace its purely descriptive approach with a theoretical approach that integrates causal information into the DSM’s descriptive diagnostic (...) categories. The paper proceeds in three sections. In the first section, I examine the goals (viz., guiding treatment, facilitating research, and improving communication) associated with the DSM’s purely descriptive approach. In the second section, I suggest that the DSM’s purely descriptive approach is best suited for improving communication among mental health professionals; however, theoretical approaches would be superior for purposes of treatment and research. In the third section, I outline steps required to move the DSM towards a hybrid system of classification that can accommodate the benefits of descriptive and theoretical approaches, and I discuss how the DSM’s descriptive categories could be revised to incorporate theoretical information regarding the causes of disorders. I argue that the DSM should reconceive of its goals more narrowly such that it functions primarily as an epistemic hub that mediates among various contexts of use in which definitions of mental disorders appear. My analysis emphasizes the importance of pluralism as a methodological means for avoiding theoretical dogmatism and ensuring that the DSM is a reflexive and self-correcting manual. (shrink)

Perspectivists hold that what you ought to do is determined by your perspective, that is, your epistemic position. Objectivists hold that what you ought to do is determined by the facts irrespective of your perspective. This paper explores an influential argument for perspectivism which appeals to the thought that the normative is action guiding. The crucial premise of the argument is that you ought to φ only if you are able to φ for the reasons which determine that you ought (...) to φ. We show that this premise can be understood in different ways. On one reading, it provides no support for perspectivism. On another reading, the premise lacks support. So, the argument fails. An important upshot of the paper is that the objectivist can embrace the thought about guidance. (shrink)

This paper defends a 'fitting attitudes' view of value on which what it is for something to be good is for there to be reasons to favour that thing. The first section of the paper defends a 'linking principle' connecting reasons and value. The second and third sections argue that this principle is better explained by a fitting-attitudes view than by 'value-first' views on which reasons are explained in terms of value.

How does consciousness vary across the animal kingdom? Are some animals ‘more conscious’ than others? This article presents a multidimensional framework for understanding interspecies variation in states of consciousness. The framework distinguishes five key dimensions of variation: perceptual richness, evaluative richness, integration at a time, integration across time, and self-consciousness. For each dimension, existing experiments that bear on it are reviewed and future experiments are suggested. By assessing a given species against each dimension, we can construct a consciousness profile for (...) that species. On this framework, there is no single scale along which species can be ranked as more or less conscious. Rather, each species has its own distinctive consciousness profile. (shrink)

A prominent objection to non-cognitive moral bio-enhancements is that they would compromise the recipient’s ‘freedom to fall’. I begin by discussing some ambiguities in this objection, before outlining an Aristotelian reading of it. I suggest that this reading may help to forestall Persson and Savulescu’s ‘God-Machine’ criticism; however, I suggest that the objection still faces the problem of explaining why the value of moral conformity is insufficient to outweigh the value of the freedom to fall itself. I also question whether (...) the objection is compatible with Neil Levy’s parity principle. Accordingly, I go on to consider an alternative relational freedom-based objection to NCMBEs that aims to explain the fundamental moral importance of the freedom that NCMBEs would violate. I argue that although this strategy might allow the critic of NCMBEs to bypass a powerful criticism of Harris’ objection, it also weakens the freedom-based objection’s compatibility with the parity principle. (shrink)

This paper focuses on an underexplored challenge in infinite ethics. On realistic assumptions, if our universe is infinite, every nomologically possible history is actual and nothing we ever do makes a difference to the moral quality of the world as a whole. Call this thought Every History. This paper unpacks Every History and explores some of its ethical implications. Specifically, I argue that if Every History is true and the universe turns out to be infinite (1) our lives are globally (...) insignificant, (2) moral principles enjoining the promotion of value need to be given an appropriately scope-restricted interpretation, and (3) impersonal consequentialism faces a serious challenge. (shrink)

Suppose that Ann says, “Keith knows that the bank will be open tomorrow.” Her audience may well agree. Her knowledge ascription may seem true. But now suppose that Ben—in a different context—also says “Keith knows that the bank will be open tomorrow.” His audience may well disagree. His knowledge ascription may seem false. Indeed, a number of philosophers have claimed that people’s intuitions about knowledge ascriptions are context sensitive, in the sense that the very same knowledge ascription can seem true (...) in one conversational context but false in another. This purported fact about people’s intuitions serves as one of the main pieces of evidence for epistemic contextualism. (shrink)

Traditionally, epistemology has been individualistic. Evidentialism fits squarely in this individualistic tradition. According to evidentialism, it is the mental states of the subject alone that fully determine what she is justified in believing. More recently, epistemology has become more and more social, moving away from this individualistic paradigm. Social epistemology examines the social nature of knowledge and rationality and thus engages in projects that are a departure from more traditional epistemology. It might be thought that social epistemology has no room (...) for the evidentialist. In this paper, I argue that one can be an evidentialist as well as a thoroughgoing social epistemologist. In section 1, I explain individualistic epistemology and evidentialism. In section 2, I highlight some of the central projects of social epistemology. In section 3, I argue that none of the projects in section 2 are in conflict with evidentialism and that many can be fruitfully pursued from within an evidentialist framework. In sections 4 – 7, I examine and respond to two challenges to a successful evidentialist social epistemology. The first, inspired by Goldberg (2010), claims that evidentialism is ill-equipped to handle the insights regarding the epistemic importance of what is happening in the minds of others. The second, inspired by Lackey (2018), claims that evidentialism is unable to address a form of epistemic injustice. I show that both challenges can be met by the evidentialist. (shrink)

This article responds to two arguments against ‘Epistemic Perceptualism’, the view that emotional experiences, as involving a perception of value, can constitute reasons for evaluative belief. It first provides a basic account of emotional experience, and then introduces concepts relevant to the epistemology of emotional experience, such as the nature of a reason for belief, non-inferentiality, and prima facie vs. conclusive reasons, which allow for the clarification of Epistemic Perceptualism in terms of the Perceptual Justificatory View. It then challenges two (...) arguments which purport to show that emotional experience is not a source of reasons for evaluative belief. The first argument claims that because normative why-questions are always appropriate in the case of emotions, then emotions can never be conclusive reasons for corresponding evaluative beliefs. The second purports to show that appeal to emotional experience as a source of reasons for evaluative beliefs renders emotions problematically self-justifying, and since emotions cannot be self-justifying, they cannot provide any sort of reason for corresponding evaluative beliefs. This article responds to these arguments, and in doing so shows there is still much to be learned about the epistemology of emotional experience by drawing analogies with perceptual experience. (shrink)

This article is an introduction to the recent debate about whether rationality is normative – that is, very roughly, about whether we should have attitudes which fit together in a coherent way. I begin by explaining an initial problem – the “detaching problem” – that arises on the assumption that we should have coherent attitudes. I then explain the prominent “wide-scope” solution to this problem, and some of the central objections to it. I end by considering the options that arise (...) if we reject the wide-scope solution. (shrink)

We are all guided by thousands of norms, but how did our capacity for normative cognition evolve? I propose there is a deep but neglected link between normative cognition and practical skill. In modern humans, complex motor skills and craft skills, such as toolmaking, are guided by internally represented norms of correct performance. Moreover, it is plausible that core components of human normative cognition evolved as a solution to the distinctive problems of transmitting complex motor skills and craft skills, especially (...) skills related to toolmaking, through social learning. If this is correct, the expansion of the normative domain beyond technique to encompass more abstract norms of fairness, reciprocity, ritual and kinship involved the elaboration of a basic platform for the guidance of skilled action by technical norms. This article motivates and defends this “skill hypothesis” for the origin of normative cognition and sets out various ways in which it could be empirically tested. (shrink)

Recent scientific research has settled on a purely descriptive definition of happiness that is focused solely on agents’ psychological states (high positive affect, low negative affect, high life satisfaction). In contrast to this understanding, recent research has suggested that the ordinary concept of happiness is also sensitive to the moral value of agents’ lives. Five studies systematically investigate and explain the impact of morality on ordinary assessments of happiness. Study 1 demonstrates that moral judgments influence assessments of happiness not only (...) for untrained participants, but also for academic researchers and even in those who study happiness specifically. Studies 2 and 3 then respectively ask whether this effect may be explained by general motivational biases or beliefs in a just world. In both cases, we find evidence against these explanations. Study 4 shows that the impact of moral judgments cannot be explained by changes in the perception of descriptive psychological states. Finally, Study 5 compares the impact of moral and non-moral value, and provides evidence that unlike non-moral value, moral value is part of the criteria that govern the ordinary concept of happiness. Taken together, these studies provide a specific explanation of how and why the ordinary concept of happiness deviates from the definition used by researchers studying happiness. (shrink)

Consciousness has an important role in ethics: when a being consciously experiences the frustration or satisfaction of its interests, those interests deserve higher moral priority than those of a behaviourally similar but non-conscious being. I consider the relationship between this ethical role and an a posteriori (or “type-B”) materialist solution to the mind-body problem. It is hard to avoid the conclusion that, if type-B materialism is correct, then the reference of the concept of phenomenal consciousness is radically indeterminate between a (...) neuronal-level property that is distinctive to mammals and a high-level functional property that is much more widely shared. This would leave many non-mammalian animals (such as birds, fish, insects and octopuses) with indeterminate moral status. There are ways to manage this radical moral indeterminacy, but all of these ways lead to profoundly troubling consequences. (shrink)

In debates about animal sentience, the precautionary principle is often invoked. The idea is that when the evidence of sentience is inconclusive, we should “give the animal the benefit of the doubt” or “err on the side of caution” in formulating animal protection legislation. Yet there remains confusion as to whether it is appropriate to apply the precautionary principle in this context, and, if so, what “applying the precautionary principle” means in practice regarding the burden of proof for animal sentience. (...) Here I construct a version of the precautionary principle tailored to the question of animal sentience together with a practical framework for implementing it. I explain and defend the key features of this framework, argue that it is well-aligned with current practice in animal welfare science, and consider and reject a number of influential counterarguments to the use of precautionary reasoning in this area. (shrink)

Past work has demonstrated that people’s moral judgments can influence their judgments in a number of domains that might seem to involve straightforward matters of fact, including judgments about freedom, causation, the doing/allowing distinction, and intentional action. The present studies explore whether the effect of morality in these four domains can be explained by changes in the relevance of alternative possibilities. More precisely, we propose that moral judgment influences the degree to which people regard certain alternative possibilities as relevant, which (...) in turn impacts intuitions about freedom, causation, doing/allowing, and intentional action. Employing the stimuli used in previous research, Studies 1a, 2a, 3a, and 4a show that the relevance of alternatives is influenced by moral judgments and mediates the impact of morality on non-moral judgments. Studies 1b, 2b, 3b, and 4b then provide direct empirical evidence for the link between the relevance of alternatives and judgments in these four domains by manipulating (rather than measuring) the relevance of alternative possibilities. Lastly, Study 5 demonstrates that the critical mechanism is not whether alternative possibilities are considered, but whether they are regarded as relevant. These studies support a unified framework for understanding the impact of morality across these very different kinds of judgments. (shrink)

Human neural organoid research is advancing rapidly. As Greely notes in the target article, this progress presents an “onrushing ethical dilemma.” We can’t rule out the possibility that suff...

This article offers an account of moods as distinctive kinds of personal level affective-evaluative states, which are both intentional and rationally intelligible in specific ways. The account contrasts with those who claim moods are non-intentional, and so also arational. Section 1 provides a conception of intentionality and distinguishes moods, as occurrent experiential states, from other states in the affective domain. Section 2 argues moods target the subject’s total environment presented in a specific evaluative light through felt valenced attitudes (the Mood-Intentionality (...) thesis). Section 3 argues some moods are experienced as rationally intelligible responses, and so epistemically appropriate, to the way ‘the world’ presents itself (the Mood-Intelligibility thesis). Finally, section 4 discusses the epistemology of moods. (shrink)

From mitochondria to meerkats, the natural world is full of spectacular examples of social behaviour. In the early 1960s W. D. Hamilton changed the way we think about how such behaviour evolves. He introduced three key innovations - now known as Hamilton's rule, kin selection, and inclusive fitness - and his pioneering work kick-started a research program now known as social evolution theory. This is a book about the philosophical foundations and future prospects of that program. [Note: only the Introduction (...) is available to download.]. (shrink)

Epistemic Courage is a timely and thought-provoking exploration of the ethics of belief, which shows why epistemology is no mere academic abstraction - the question of what to believe couldn't be more urgent. Jonathan Ichikawa argues that a skeptical, negative bias about belief is connected to a conservative bias that reinforces the status quo.

Sentience is the capacity to have feelings, such as feelings of pain, pleasure, hunger, thirst, warmth, joy, comfort and excitement. It is not simply the capacity to feel pain, but feelings of pain, distress or harm, broadly understood, have a special significance for animal welfare law. Drawing on over 300 scientific studies, we evaluate the evidence of sentience in two groups of invertebrate animals: the cephalopod molluscs or, for short, cephalopods (including octopods, squid and cuttlefish) and the decapod crustaceans or, (...) for short, decapods (including crabs, lobsters and crayfish). We also evaluate the potential welfare implications of current commercial practices involving these animals. (shrink)

Emotion theory includes attempts to reduce or assimilate emotions to states such as bodily feelings, beliefs-desire combinations, and evaluative judgements. Resistance to such approaches is motivated by the claim that emotions possess a sui generis phenomenology. Uriah Kriegel defends a new form of emotion reductivism which avoids positing irreducible emotional phenomenology by specifying emotions’ phenomenal character in terms of a combination of other phenomenologies. This article argues Kriegel’s approach, and similar proposals, are unsuccessful, since typical emotional experiences are constituted by (...) sui generis feelings towards value. (shrink)

There is no agreement on whether any invertebrates are conscious and no agreement on a methodology that could settle the issue. How can the debate move forward? I distinguish three broad types of approach: theory-heavy, theory-neutral and theory-light. Theory-heavy and theory-neutral approaches face serious problems, motivating a middle path: the theory-light approach. At the core of the theory-light approach is a minimal commitment about the relation between phenomenal consciousness and cognition that is compatible with many specific theories of consciousness: the (...) hypothesis that phenomenally conscious perception of a stimulus facilitates, relative to unconscious perception, a cluster of cognitive abilities in relation to that stimulus. This “facilitation hypothesis” can productively guide inquiry into invertebrate consciousness. What is needed? At this stage, not more theory, and not more undirected data gathering. What is needed is a systematic search for consciousness-linked cognitive abilities, their relationships to each other, and their sensitivity to masking. (shrink)

Recently, more attention has been paid to the nature and value of the intellectual virtue of epistemic autonomy. One underexplored issue concerns how epistemic autonomy is related to other intellectual virtues. Plausibly, epistemic autonomy is closely related to a number of intellectual virtues like curiosity, inquisitiveness, intellectual perseverance, and intellectual courage to name just a few. Here, however, I will examine the relation between epistemic autonomy and intellectual humility. I will argue that epistemic autonomy and intellectual humility bear an interesting (...) relationship to one another in that they are interconnected and mutually supporting intellectual virtues. In sections 2 and 3 I will provide a brief overview of the predominant accounts of intellectual humility (section 2) and epistemic autonomy (section 3) in the literature. With an understanding of these intellectual virtues in hand, we will examine their relationship of mutual support in section 4. Section 5 will explore a challenge to this relationship coming from the epistemology of disagreement, and section 6 concludes. (shrink)

Over the past two decades, Ginsburg and Jablonka have developed a novel approach to studying the evolutionary origins of consciousness: the Unlimited Associative Learning framework. The central idea is that there is a distinctive type of learning that can serve as a transition marker for the evolutionary transition from non-conscious to conscious life. The goal of this paper is to stimulate discussion of the framework by providing a primer on its key claims and a clear statement of its main empirical (...) predictions. (shrink)

Enkratic reasoning—reasoning from believing that you ought to do something to an intention to do that thing—seems good. But there is a puzzle about how it could be. Good reasoning preserves correctness, other things equal. But enkratic reasoning does not preserve correctness. This is because what you ought to do depends on your epistemic position, but what it is correct to intend does not. In this paper, I motivate these claims and thus show that there is a puzzle. I then (...) argue that the best solution is to deny that correctness is always independent of your epistemic position. As I explain, a notable upshot is that a central epistemic norm directs us to believe, not simply what is true, but what we are in a position to know. (shrink)

This paper first demonstrates that recognition of the diversity of ways that emotional responses modulate ongoing attention generates what I call the puzzle of emotional attention, which turns on recognising that distinct emotions (e.g., fear, happiness, disgust, admiration etc.) have different attentional profiles. The puzzle concerns why this is the case, such that a solution consists in explaining why distinct emotions have the distinct attentional profiles they do. It then provides an account of the functional roles of different emotions, as (...) tied to their evaluative themes, which explains and further elucidates the distinctive attentional profiles of different emotions, so solving the puzzle of emotional attention. Following that, it outlines how such attentional profiles are reflected in the character of emotional experience and its attentional phenomenology. The resulting picture is a more detailed account of the connections between emotion and attention than is currently on offer in the philosophical literature. (shrink)

According to an intriguing though somewhat enigmatic line of thought first proposed by Jonathan Bennett, if humanity went extinct any time soon this would be unfortunate because important business would be left unfinished. This line of thought remains largely unexplored. I offer an interpretation of the idea that captures its intuitive appeal, is consistent with plausible constraints, and makes it non-redundant to other views in the literature. The resulting view contrasts with a welfare-promotion perspective, according to which extinction would (...) be bad because it would come at a massive opportunity cost in terms of feasibly achievable welfare over the lifetime of our species. (shrink)

Summary. The viability of the proposal that human cognition involves the utilization of nonsentential models is seriously undercut by the fact that no one has yet given a satisfactory account of how neurophysiological circuitry might realize representations of the right sort. Such an account is offered up here, the general idea behind which is that high-level models can be realized by lower—level computations and, in turn, by neural machinations. It is shown that this account can be usefully applied to deal (...) with problems in fields ranging from artificial intelligence to the philosophy of science. (shrink)