We report an experiment investigating the “special-process” theory of insight problem solving, which claims that insight arises from non-conscious, non-reportable processes that enable problem re-structuring. We predicted that reducing opportunities for speech-based processing during insight problem solving should permit special processes to function more effectively and gain conscious awareness, thereby facilitating insight. We distracted speech-based processing by using either articulatory suppression or irrelevant speech, with findings for these conditions supporting the predicted insight facilitation effect relative to silent working or thinking (...) aloud. The latter condition was included to investigate the currently contested effect of “verbal overshadowing” on insight, whereby thinking aloud is claimed to hinder the operation of special, non-reportable processes. Whilst verbal overshadowing was not evident in final solution rates, there was nevertheless support for verbal overshadowing up to and beyond.. (shrink)

It is widely accepted that public discourse as we know it is less than ideal from an epistemological point of view. In this paper, we develop an underappreciated aspect of the trouble with public discourse: what we call the Listening Problem. The listening problem is the problem that public discourse has in giving appropriate uptake and reception to ideas and concepts from oppressed groups. Drawing on the work of Jürgen Habermas and Nancy Fraser, we develop an institutional response to the (...) listening problem: the establishment of what we call Receptive Publics, discursive spaces designed to improve listening skills and to give space for counterhegemonic ideas. (shrink)

Despite increasing pressure to deal with climate change, firms have been slow to respond with effective action. This article presents a multi-level framework for a better understanding of why many firms are failing to reduce their absolute greenhouse gas emissions, which contribute to climate change. The concepts of short-termism and uncertainty avoidance from research in psychology, sociology, and organization theory can explain the phenomenon of organizational inaction on climate change. Antecedents related to short-termism and uncertainty avoidance reinforce one another at (...) three levels—individual, organizational, and institutional—and result in organizational inaction on climate change. The article also discusses the implications of this multi-level framework for research on corporate sustainability. (shrink)

To be a doxastic deontologist is to claim that there is such a thing as an ethics of belief (or of our doxastic attitudes in general). In other words, that we are subject to certain duties with respect to our doxastic attitudes, the non-compliance with which makes us blameworthy and that we should understand doxastic justification in terms of these duties. In this paper, I argue that these duties are our all things considered duties, and not our epistemic or moral (...) duties, for example. I show how this has the surprising result that, if deontologism is a thesis about doxastic justification, it entails that there is no such thing as epistemic or moral justification for a belief that p. I then suggest why this result, though controversial, may have some salutary consequences: primarily that it helps us make some sense of an otherwise puzzling situation regarding doxastic dilemmas. -/- . (shrink)

Orthodox semantics for natural language modals give rise to two puzzles for their interactions with disjunction: Ross’s puzzle and the puzzle of free choice permission. It is widely assumed that each puzzle can be explained in terms of the licensing of ‘Diversity’ inferences: from the truth of a possibility or necessity modal with an embedded disjunction, hearers infer that each disjunct is compatible with the relevant set of worlds. I argue that Diversity inferences are too weak to explain the full (...) range of data. Instead, I argue, modals with embedded disjunctions license ‘Independence’ inferences: from the truth of a modal with an embedded disjunction, hearers infer that each disjunct is an independent alternative among the relevant set of worlds. I then develop a bilateral inquisitive semantics for modals that predicts the validity of these Independence inferences. My account vindicates common intuitions about both Ross’s puzzle and the puzzle of free choice permission, and explains the full range of data. (shrink)

Signals to the brain from the flows of energy around the body, varied primarily by declining amounts of food energy in the stomach, can explain the pattern of meals in the laboratory rat, the differences between dark and light phases, and the development of obesity ion the rat wioth VMH lesions but normal sating.

I introduce a new version of Moral Error Theory, which I call Type-B Moral Error Theory. According to a Type-B theorist there are no facts of the kind required for there to be morality instricto sensu, but there can be irreducible ‘normative’ properties which she deems, strictly speaking, to be morally irrelevant. She accepts that there areinstrumentalall things considered oughts, andcategoricalpro tanto oughts (both of which she deems morally irrelevant), but denies that there arecategoricalall things considered oughts on pain of (...) requiring ‘queer’ facts to obtain. I detail the most central motivation of this version of the theory against its more traditional rival, according to which there are no irreducible normative properties at all. The motivation is that it, unlike its rival, can successfully be defended against the notorious charge of self-defeat. (shrink)

The debate between “Normativists” and “Teleologists” about the normativity of belief has been taken to hinge on the question of which of the two views best explains why it is that we cannot believe at will. Of course, this presupposes that there is an explanation to be had. Here, I argue that this supposition is unwarranted, that Doxastic Involuntarism is merely contingently true. I argue that this is made apparent when we consider that suspended judgement must be involuntary if belief (...) is, that suspended judgment is not a belief, and that the aim or norm of suspended judgement cannot be constitutive if suspended judgement is not a belief. (shrink)

In this paper I consider whether there can be such things as epistemic reasons for action. I consider three arguments to the contrary and argue that none are successful, being either somewhat question-begging or too strong by ruling out what most epistemologists think is a necessary feature of epistemic justification, namely the epistemic basing relation. I end by suggesting a "non-cognitivist" model of epistemic reasons that makes room for there being epistemic reasons for action and suggest that this model may (...) support moral realism. (shrink)

Matthias Steup (Steup 2008) has recently argued that our doxastic attitudes are free by (i) drawing an analogy with compatibilism about freedom of action and (ii) denying that it is a necessary condition for believing at will that S's having an intention to believe that p can cause S to believe that p . In this paper, however, I argue that the strategies espoused in (i) and (ii) are incompatible.

The Nuffield Council on Bioethics (NCOB) is delighted to pick up the mantel of the Ethics briefings. For readers less familiar with the NCOB’s work, we are a leading independent policy and research centre, and the foremost bioethics body in the UK. We identify, analyse and advise on ethical issues in biomedicine and health so that decisions in these areas benefit people and society.1 Established in 1991, the NCOB has tackled a wide range of bioethics and medical ethics issues over (...) its thirty-two years, including issues relating to the beginning and end of life, health and society, data and technology, and research ethics. Early reports in the 1990s included, for example, ‘Genetics screening: the ethical issues’ and ‘Animal-to-human transplants: the ethics of Xenotransplantation’. More recent projects include setting out an ethical framework in the report ‘The future of ageing: ethical considerations for research and innovation’2 and a current joint project with the Ada Lovelace Institute3 considering the potential ethical implications of the convergence of AI and genomics technologies.4 In recent years, NCOB has increasingly focused on horizon scanning. What current and future national and international developments are likely to raise ethical issues in the short, medium and long-term? Insights for 2023 will soon be available at www.nuffieldbioethics.org/what-we-do/horizon-scanning, with new developments likely to be included alongside ongoing areas of medical and scientific research that we are tracking progress in, for example, in vitro derived gametes, surrogacy, biosafety and novel neurotechnologies. Disagreements between parents and healthcare teams about …. (shrink)

Richard Foley has suggested that the search for a good theory of epistemic justification and the analysis of knowledge should be conceived of as two distinct projects. However, he has not offered much support for this claim, beyond highlighting certain salutary consequences it might have. In this paper, I offer some further support for Foley’s claim by offering an argument and a way to conceive the claim in a way that makes it as plausible as its denial, and thus levelling (...) the playing field. The burden of proof then lies with those who seek to deny Foley’s radical suggestion. (shrink)

Most approaches to iterated belief revision are accompanied by some motivation for the use of the proposed revision operator (or family of operators), and typically encode enough information in the epistemic state of an agent for uniquely determining one-step revision. But in those approaches describing a family of operators there is usually little indication of how to proceed uniquely after the first revision step. In this paper we contribute towards addressing that deficiency by providing a formal framework which goes beyond (...) the first revision step in two ways. First, the framework is obtained by enriching the epistemic state of an agent starting from the following intuitive idea: we associate to each world x two abstract objects x⁺ and x⁻, and we assume that, in addition to preferences over the set of worlds, we are given preferences over this set of objects as well. The latter can be considered as meta-information encoded in the epistemic state which enables us to go beyond the first revision step of the revision operator being applied, and to obtain a unique set of preferences over worlds. We then extend this framework to consider, not only the revision of preferences over worlds, but also the revision of this extended structure itself. We look at some desirable properties for revising the structure and prove the consistency of these properties by giving a concrete operator satisfying all of them. Perhaps more importantly, we show that this framework has strong connections with two other types of constructions in related areas. Firstly, it can be seen as a special case of preference aggregation which opens up the possibility of extending the frame-work presented here into a full-fledged framework for preference aggregation and social choice theory. Secondly, it is related to existing work on the use of interval orderings in a number of different contexts. (shrink)

I argue that the claim that epistemic ought is incommensurable is self-defeating. My argument, however, depends on the truth of the premise that there can be not only epistemic reasons for belief, but also non-epistemic reasons for belief. So I also provide some support for that claim.

I introduce a new version of Moral Error Theory, which I call Type-B Moral Error Theory. According to a Type-B theorist there are no facts of the kind required for there to be morality in stricto sensu, but there can be irreducible ‘normative’ properties which she deems, strictly speaking, to be morally irrelevant. She accepts that there are instrumental all things considered oughts, and categorical pro tanto oughts, but denies that there are categorical all things considered oughts on pain of (...) requiring ‘queer’ facts to obtain. I detail the most central motivation of this version of the theory against its more traditional rival, according to which there are no irreducible normative properties at all. The motivation is that it, unlike its rival, can successfully be defended against the notorious charge of self-defeat. (shrink)

Background: Fetal alcohol spectrum disorder (FASD), a complex diagnosis that includes a wide range of neurodevelopmental disabilities, results from exposure to alcohol in the womb. FASD remains poorly understood by Canadians, which could contribute to reported stigma faced by both people with FASD and women who drink alcohol while pregnant. Methods: To better understand how information about FASD is presented in the public sphere, we conducted content analysis of 286 articles from ten major English-language Canadian newspapers (2002-2015). We used inductive (...) coding to derive a coding guide from the data, and then iteratively applied identified codes back onto the sample, checking inter-coder reliability. Results: We identified six major themes related to clinical and scientific media content: 1) prevalence of FASD and of women’s alcohol consumption; 2) research related to FASD; 3) diagnosis of FASD; 4) treatment of FASD and maternal substance abuse; 5) primary disabilities associated with FASD; and 6) effects of alcohol exposure during pregnancy. Discussion: Across these six themes, we discuss three instances of ethically consequential exaggeration and misrepresentation: 1) exaggeration about FASD rates in Indigenous communities; 2) contradiction between articles about the effects of prenatal alcohol exposure; and 3) scientifically accurate information that neglects the social context of alcohol use and abuse by women. Respectively, these representations could lead to harmful stereotyped beliefs about Indigenous peoples, might generate confusion about healthy choices during pregnancy, and may unhelpfully inflame debates about sensitive issues surrounding women’s choices. (shrink)

ABSTRACTPeople high in negative affect tend to think negative events are more likely than positive events. Studies have found that weak attentional control exaggerates another...

To contribute more effectively to conservation reform, environmental ethics needs a motivational turn, referenced to the best scientific information about motivation. I address the pivotal questions What actually motivates people to conserve nature? and What ought to motivate people to conserve nature? by proposing a framework for understanding motivations and developing motivationally relevant criteria for environmental ethics. The need for an adequate philosophy of psychology for moral philosophy, identified by Elizabeth Anscombe 50 years ago, remains. Only from a psychologically informed (...) motivational framework for morality can ethicists understand and address the widespread rhetoric behaviors gap plaguing conservation. (shrink)

The notion of the rational closure of a positive knowledge base K of conditional assertions θ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} |∼ φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} (standing for if θ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} then normally φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document}) was first introduced by Lehmann (1989) and developed by Lehmann and Magidor (...) (1992). Following those authors we would also argue that the rational closure is, in a strong sense, the minimal information, or simplest, rational consequence relation satisfying K. In practice, however, one might expect a knowledge base to consist not just of positive conditional assertions, θ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} |∼ φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document}, but also negative conditional assertions, θi φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} (standing for not if θ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document} then normally φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$i$$ \end{document}. Restricting ourselves to a finite language we show that the rational closure still exists for satisfiable knowledge bases containing both positive and negative conditional assertions and has similar properties to those exhibited in Lehmann and Magidor (1992). In particular an algorithm in Lehmann and Magidor (1992) which constructs the rational closure can be adapted to this case and yields, in turn, completeness theorems for the conditional assertions entailed by such a mixed knowledge base. (shrink)

We provide a formal study of belief retraction operators that do not necessarily satisfy the postulate. Our intuition is that a rational description of belief change must do justice to cases in which dropping a belief can lead to the inclusion, or ‘liberation’, of others in an agent's corpus. We provide two models of liberation via retraction operators: ρ-liberation and linear liberation. We show that the class of ρ-liberation operators is included in the class of linear ones and provide axiomatic (...) characterisations for each class. We show how any retraction operator can be ‘converted’ into either a withdrawal operator ) or a revision operator via the Harper Identity and the Levi Identity respectively. (shrink)

Direct Doxastic Voluntarism — the notion that we have direct voluntary control over our beliefs — has widely been held to be false. There are, however, two ways to interpret the impossibility of our having doxastic control: as either a conceptual/ logical/metaphysical impossibility or as a psychological impossibility. In this paper I analyse the arguments for and against both types of claim and, in particular, evaluate the bearing that putative cases of self-deception have on the arguments in defence of voluntarism (...) about belief. For it would seem that if it is the case that self-induced cases of self-deception are indeed possible, then voluntarism about belief could be true after all. Bennett claims that Williams’ argument for the impossibility case proves too much in that if it is successful in ruling out direct doxastic voluntarism, it is also successful in ruling out cases of indirect doxastic voluntarism. If cases of self-deception can also be cases of indirect doxastic voluntarism, then such cases support the argument against the impossibility case. I argue that Bennett is right in claiming that Williams’ argument proves too much, that cases of self-deception are indeed also sometimes cases of indirect self-deception and so that they cause genuine trouble for the conceptual impossibility case. However, I also argue that this is the only genuine worry for Williams’ argument. I end, while considering whether cases of self-deception can tell us anything about the psychological possibility of direct doxastic control, by suggesting a way of establishing the conceptual impossibility of direct doxastic control that circumvents Bennett’s counter-argument. (shrink)

According to a simple theory of the relationship between 'want' ascriptions and the desires they ascribe, when I learn that ⌜A wants p⌝ is true, I learn that the truth of p is necessary and sufficient for satisfying one of A’s desires. I argue that this simple theory is false: ⌜A wants p⌝ can be true and underspecific: p may be necessary but not sufficient for the satisfaction of one of A’s desires. I show that existing semantics for 'want' cannot (...) account for this kind of underspecificity, and I propose a desire-based semantics for ‘want’ that can. I go on to argue that my semantics has empirical and methodological advantages over existing theories of ‘want’ that give truth conditions in terms of an agent’s preferential and doxastic state rather than their desires. -/- . (shrink)

In this paper I hope to demonstrate two different ways of interpreting the tenets of evidentialism and show why it is important to distinguish between them. These two ways correspond to those proposed by Feldman and Adler. Feldman’s way of interpreting evidentialism makes evidentialism a principle about epistemic justification, about what we ought to believe. Adler’s, on the other hand, makes evidentialism a principle about how we come to believe, what it is, broadly speaking, rational for us to believe. Having (...) identified this difference, I consider two complaints levied against evidentialism, namely what I call the threshold problem and what I call the availability problem, and hope to show that: only an independent, bracketed justification principle of evidentialism can deal with those problems; the rationality principle of evidentialism is not in fact independent from the justification principle; the rationality principle is hard to motivate; and that in the final analysis the argument for the justification principle depends on the rationality principle. I thus conclude that although it may be convenient for evidentialists to treat these two principles as independent, such an independence cannot be maintained. (shrink)

We look at the problem of revising fuzzy belief bases, i.e., belief base revision in which both formulas in the base as well as revision-input formulas can come attached with varying degrees. Working within a very general framework for fuzzy logic which is able to capture certain types of uncertainty calculi as well as truth-functional fuzzy logics, we show how the idea of rational change from “crisp” base revision, as embodied by the idea of partial meet (base) revision, can be (...) faithfully extended to revising fuzzy belief bases. We present and axiomatise an operation of partial meet fuzzy base revision and illustrate how the operation works in several important special instances of the framework. We also axiomatise the related operation of partial meet fuzzy base contraction. (shrink)

Rowbottom (2008) has recently challenged my definition of epistemic reasons for action and has offered an alternative account. In this paper, I argue that less than giving an 'alternative' definition, Rowbottom has offered an additional condition to my original account. I argue, further, that such an extra condition is unnecessary, i.e. that the arguments designed to motivate it do not go through.

in 1612, lodovico cigoli completed a fresco in the pauline chapel of the basilica of santa maria maggiore in rome depicting apocalypse 12: “a woman clothed with the sun, and the moon under her feet.” he showed the crescent moon with spots, as his friend galileo had observed with the newly invented telescope. considerations of the orthodox view of the perfect moon as held by philosophers have led historians to ask why this clearly imperfect moon in a religious painting raised (...) no eyebrows. we argue that when considered in the context of biblical interpretation and the rhetoric of the counter-reformation, the imperfect moon under the woman's feet was entirely consistent with traditional interpretations of apocalypse 12. (shrink)

A common belief about the nature of agent regret is that regretting some event E is closely linked to being sorry for the occurrence of E. Or more specifically, that if one is sorry for E then she must regret E. I will call this ‘the sorry-regret hypothesis’. My contention is that one may be sorry for some action but not regret it. I take the rejection of this ‘truism’ to be a positive development. I offer two lines of argument (...) for rejecting the sorry-regret hypothesis. One line of argument is based on counterexamples. The second attacks the validity of a reconstructed argument for the sorry-regret hypothesis. It is desirable to reject the sorry-regret hypothesis since there is a component of regret that many will not wish to be saddled with as a condition of apologizing. To regret an act, one must wish that she had not performed that act. Since a person is the person she is (speaking loosely) because of the actions she has performed, for many actions, if one regrets an action, then she wishes that she were a different person. This is a worrisome consequence. (shrink)

This paper comprises a defence of Infallibilism about knowledge. In it, I articulate two arguments in favour of Infallibilism, and for each argument show that Infallibilism about knowledge does not lead to an unpalatable Scepticism if justified belief is neither necessary nor sufficient for knowledge, and if Fallibilism about justified belief is true.

Socrates said that leisure is the sister of freedom.Aelian.

Chimpanzee language studies have generated much heated controversy, as Roger Fouts can attest from firsthand experience. Perhaps this is because language is usually considered to be what truly distinguishes humans from apes. If chimps can indeed be taught the rudiments of language, then the difference between them and us is not as great as we might have thought. It is a matter of degree rather than kind, a continuity, and our species is not so special after all. The advantage of (...) this continuity thesis, as Fouts has emphasized, is that it conforms to the general tenets of evolutionary theory, and fits well with the evidence from paleontology and genetics that suggests that apes and humans are close cousins. It also .. (shrink)

Suboptimality of decision making needs no explanation. High level accounts of suboptimality in diverse tasks cannot add up to a mechanistic theory of perceptual decision making. Mental processes operate on the contents of information brought by the experimenter and the participant to the task, not on the amount of information in the stimuli without regard to physical and social context.

In recent years many eco-phenomenological philosophers have argued that a more positive analysis of one’s relationship with more-than-human nature can be achieved through taking up Maurice Merleau-Ponty’s ontology of the flesh. Taking such an ontology seriously seems to facilitate even the possibility of our being able to express “what the world means to say.” I argue, however, that we should be cautious about both taking up such an ontology and making such ontological claims because in doing so we fail to (...) take sufficiently seriously the impact of sedimentation in both perception and reflection and thus violate the remit of radical reflection that is essential to Merleau-Ponty’s characterization of philosophy. (shrink)

According to many philosophers there are only pro tanto oughts to believe relative to a standard of assessment: there are epistemic oughts to believe, moral oughts to believe, prudential oughts to believe etc. But there are no oughts to believe simpliciter. Many of the same philosophers who hold this view, also hold that ought to believe is to be understood deontologically – such that if S violates such an ought without excuse, S is blameworthy for doing so. I here argue (...) that on a deontological understanding of ought to believe there must be ought to believe simpliciter and that it is the violation of this ought that determines whether we are to blame for our beliefs. (shrink)

In this paper we present a modal logic framework to reason about the expertise of information sources. A source is considered an expert on a proposition φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document} if they are able to correctly refute φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document} in any possible world where φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document} is false. Closely connected with expertise is a notion of (...) soundness of information: φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document} is said to be “sound” if it is true up to lack of expertise of the source. That is, any statement logically weaker than φ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varphi $$\end{document} on which the source has expertise must in fact be true. This is relevant for modelling situations in which sources make claims beyond their domain of expertise. Particular attention is paid to the connection between expertise and knowledge: we show that expertise and soundness admit precise interpretations in terms of S4 and S5 epistemic logic, under certain conditions. We go on to extend the framework to multiple sources, defining two notions of collective expertise. These also have epistemic interpretations via distributed and common knowledge from multi-agent epistemic logic. On the technical side, we give several sound and complete axiomatisations of various classes of expertise models. (shrink)