In chapter 5 of Knowledge and its Limits, T. Williamson formulates an argument against the principle (KK) of epistemic transparency, or luminosity of knowledge, namely “that if one knows something, then one knows that one knows it”. Williamson’s argument proceeds by reductio: from the description of a situation of approximate knowledge, he shows that a contradiction can be derived on the basis of principle (KK) and additional epistemic principles that he claims are better grounded. One of them is a reflective (...) form of the margin for error principle defended by Williamson in his account of knowledge. We argue that Williamson’s reductio rests on the inappropriate identification of distinct forms of knowledge. More specifically, an important distinction between perceptual knowledge and non-perceptual knowledge is wanting in his statement and analysis of the puzzle. We present an alternative account of this puzzle, based on a modular conception of knowledge: the (KK) principle and the margin for error principle can coexist, provided their domain of application is referred to the right sort of knowledge. (shrink)

Ginger Schultheis offers a novel and interesting argument against epistemic permissivism. While we think that her argument is ultimately uncompelling, we think its faults are instructive. We explore the relationship between epistemic permissivism, Margin-for-Error principles, and an epistemological version of Dominance reasoning.

A joint modelling of objective worlds and subjective perceptions within two-dimensional semantics eliminates the margin for error principle and solves the epistemic sorites paradox. Two objective knowledge modalities can be defined in two-dimensional frames accounting for subjective perceptions: “necessary knowledge” (NK) and “possible knowledge” (PK), the latter being better suited to the interpretation of knowledge utterances. Two-dimensional semantics can in some cases be reduced to one-dimensional ones, by defining accessibility relations between objective worlds that reflect subjective perceptions: NK and (...) PK are respectively equivalent to ${\square \square }$ and ${\lozenge \square }$ in some one-dimensional frame, and to ${\square }$ and another modality in some other. (shrink)

Forthcoming in D.H. Pritchard & V. Hendricks, New Waves in Epistemology,.

I address Peter Mott's 'Margins for Error and the Sorites Paradox' , pp. 494–503). Mott criticizes my account of inexact knowledge, on which it satisfies margin for error principles of the form 'If one knows in a given case, one avoids false belief in sufficiently similar cases'. Mott's arguments are shown to be fallacious because they ignore the fact that our knowledge of inexact knowledge is itself inexact. In the examples discussed, the first-level inexact knowledge is perceptual. (...) Since my defense of an epistemicist theory of vagueness explains our ignorance of truth-values in borderline cases as the result of knowledge the inexactness of which has a conceptual source, the paper also contributes to the defense of epistemicism about vagueness. (shrink)

Timothy Williamson has provided damaging counterexamples to Robert Nozick’s sensitivity principle. The examples are based on Williamson’s anti-luminosity arguments, and they show how knowledge requires a margin for error that appears to be incompatible with sensitivity. I explain how Nozick can rescue sensitivity from Williamson’s counterexamples by appeal to a specific conception of the methods by which an agent forms a belief. I also defend the proposed conception of methods against Williamson’s criticisms.

Williamson (2000a) has argued that posi- tive introspection is incompatible with in- exact knowledge. His argument relies on a margin-for-error requirement for inexact knowledge based on a intuitive safety prin- ciple for knowledge, but leads to the counter- intuitive conclusion that no possible creature could have both inexact knowledge and posi- tive introspection. Following Halpern (2004) I put forward an alternative margin-for-error requirement that preserves the safety require- ment while blocking Williamson’s argument. I argue that the infallibilist conception (...) of knowledge that underlies the new require- ment provides a better account of inexact knowledge and higher-order knowledge than both Williamson’s and Halpern’s. (shrink)

Timothy Williamson’s potentially most important contribution to epistemicism about vagueness lies in his arguments for the basic epistemicist claim that the alleged cut-off points of vague predicates are not knowable. His arguments for this are based on so-called ‘margin for error principles’. This paper argues that these principles fail to provide a good argument for the basic claim. Williamson has offered at least two kinds of margin for error principles applicable to vague predicates. A certain fallacy of equivocation (...) seems to underlie his justification for both kinds of principles. Besides, the margin for error principles of the first kind can be used in the derivation of unacceptable consequences, while the margin for error principles of the second kind can be shown to be compatible with the falsity of epistemicism, under a number of assumptions acceptable to the epistemicist. (shrink)

Epistemicists say there is a last positive instance in a sorites sequence-we just cannot know which is the last. Timothy Williamson explains that knowledge requires a margin for error and this ensures that the last heap will not be knowable as a heap. However, there is a class of disjunctive predicates for which knowledge at the thresholds is possible. They generate sorites paradoxes that cannot be diagnosed with the margin for error principle.

Roy Sorensen's criticism of my use of margin for error principles to explain ignorance in borderline cases fails because it misidentifies the relevant margin for error principles. His alternative explanation in terms of truth-maker gaps is briefly criticized.

This paper considers, and rejects, three strategies aimed at showing that the KK-principle fails even in most favourable circumstances (all emerging from Williamson’s Knowledge and its Limits ). The case against the final strategy provides positive grounds for thinking that the principle should hold good in such situations.

We argue that the epistemic theory of vagueness cannot adequately justify its key tenet-that vague predicates have precisely bounded extensions, of which we are necessarily ignorant. Nor can the theory adequately account for our ignorance of the truth values of borderline cases. Furthermore, we argue that Williamson’s promising attempt to explicate our understanding of vague language on the model of a certain sort of “inexact knowledge” is at best incomplete, since certain forms of vagueness do not fit Williamson’s model, and (...) in fact fit an alternative model. Finally, we point out that a certain kind of irremediable inexactitude postulated by physics need not be-and is not commonly-interpreted as epistemic. Thus, there are aspects of contemporary science that do not accord well with the epistemicist outlook. (shrink)

Let us say that the proposition that p is transparent just in case it is known that p, and it is known that it is known that p, and it is known that it is known that it is known that p, and so on, for any number of iterations of the knowledge operator ‘it is known that’. If there are transparent propositions at all, then the claim that any man with zero hairs is bald seems like a good candidate. (...) We know that any man with zero hairs is bald. And it also does not seem completely implausible that we know that we know it, and that we know that we know that we know it, and so on. (shrink)

In their paper “Vagueness, Ignorance, and Margins for Error” Kenton Machina and Harry Deutsch criticize the epistemic theory of vagueness. This paper answers their objections. The main issues discussed are: the relation between meaning and use; the principle of bivalence; the ontology of vaguely specified classes; the proper form of margin for error principles; iterations of epistemic operators and semantic compositionality; the relation or lack of it between quantum mechanics and theories of vagueness.

According to the KK-principle, knowledge iterates freely. It has been argued, notably in Greco, that accounts of knowledge which involve essential appeal to normality are particularly conducive to defence of the KK-principle. The present article evaluates the prospects for employing normality in this role. First, it is argued that the defence of the KK-principle depends upon an implausible assumption about the logical principles governing iterated normality claims. Once this assumption is dropped, counter-instances to the principle can be expected to arise. (...) Second, it is argued that even if the assumption is maintained, there are other logical properties of normality which can be expected to lead to failures of KK. Such failures are noteworthy, since they do not depend on either a margins-for-error principle or safety condition of the kinds Williamson appeals to in motivating rejection KK. “Introduction: KK and Being in a Position to Know” Section formulates two versions of the KK-Principle; “Inexact Knowledge and Margins for Error” Section presents a version of Williamson’s margins-for-error argument against it; “Knowledge and Normality” and “Iterated Normality” Sections discuss the defence of the KK-Principle due to Greco and show that it is dependent upon the implausible assumption that the logic of normality ascriptions is at least as strong as K4; finally, “Knowledge in Abnormal Conditions” and “Higher-Order Ignorance Inside the Margins” Sections argue that a weakened version of Greco’s constraint on knowledge is plausible and demonstrate that this weakened constraint will, given uncontentious assumptions, systematically generate counter-instances to the KK-principle of a novel kind. (shrink)

One of the significant problems for philosophy’s development into a more diverse discipline is the familiar sharp reduction in the proportion of women and students of color after initial, introductory-level courses. This contributes to a lack in the breadth of perspective and experience that both upper-level students and faculty bring to philosophy, which in turn undermines the strength of the discipline as a whole. Much of the transformation of philosophy must necessarily happen at the departmental, and even university, level; but (...) there are, nonetheless, a number of strategies available to individual teachers of philosophy to help to retain marginalized students—from the composition of course syllabi and assignment choices, to increased awareness of challenges within the discipline to students’ success and embracing error as a learning tool. This variety of pedagogical tools provides a means to help to make philosophy more broadly inclusive. (shrink)

This paper examines the implications of certain social psychological experiments for moral theory—specifically, for virtue theory. Gilbert Harman and John Doris have recently argued that the empirical evidence offered by ‘situationism’ demonstrates that there is no such thing as a character trait. I dispute this conclusion. My discussion focuses on the proper interpretation of the experimental data—the data themselves I grant for the sake of argument. I develop three criticisms of the anti-trait position. Of these, the central criticism concerns three (...) respects in which the experimental situations employed to test someone's character trait are inadequate to the task. First, they do not take account of the subject's own construal of the situation. Second, they include behaviour that is only marginally relevant to the trait in question. Third, they disregard the normative character of the responses in which virtue theory is interested. Given these inadequacies in situationism's operationalized conception of a ‘character trait’, I argue that situationism does not really address the proposition that people have ‘character traits’, properly understood. A fortiori, the social psychological evidence does not refute that proposition. I also adduce some limited experimental evidence in favour of character traits and distil two lessons we can nevertheless learn from situationism. (shrink)

Timothy Williamson claims that margin for error principles govern all cases of inexact knowledge. I show that this claim is unfounded: there are cases of inexact knowledge where Williamson’s argument for margin for error principles does not go through. The problematic cases are those where the value of the relevant parameter is fixed across close cases. I explore and reject two responses to my objection, before concluding that Williamson’s account of inexact knowledge is not compelling.

This paper argues that two widely accepted principles about the indicative conditional jointly presuppose the falsity of one of the most prominent arguments against epistemological iteration principles. The first principle about the indicative conditional, which has close ties both to the Ramsey test and the “or‐to‐if” inference, says that knowing a material conditional suffices for knowing the corresponding indicative. The second principle says that conditional contradictions cannot be true when their antecedents are epistemically possible. Taken together, these principles entail that (...) it is impossible to be in a certain kind of epistemic state: namely, a state of ignorance about which of two partially overlapping bodies of knowledge corresponds to one's actual one. However, some of the more popular “margin for error” style arguments against epistemological iteration principles suggest that such states are not only possible, but commonplace. I argue that the tension between these views runs deep, arising just as much for non‐factive attitudes like belief, presupposition, and certainty. I also argue that this is worse news for those who accept the principles about the indicative conditional than it is for those who reject epistemological iteration principles. (shrink)

This paper presents some difficulties for Timothy Williamson's epistemicist view of vagueness and for an argument he gives in its defense. First, I claim that the argument, which uses the notion of an "omniscient speaker", is question-begging. Next, I argue that some presumably true scientific hypotheses, which postulate certain relations between everyday vague predicates and scientific predicates, make the central theses of epistemicism highly implausible. Finally, I show that the "margin for error principles" used by Williamson to explain away (...) the kind of ignorance conjectured by epistemicism lead to new sorites-like arguments with unacceptable conclusions. (shrink)

Williamson (2000) argues that the KK principle is inconsistent with knowledge of margin for error in cases of inexact perceptual observations. This paper argues, primarily by analogy to a different scenario, that Williamson’s argument is fallacious. Margin for error principles describe the agent’s knowledge as a result of an inexact perceptual event, not the agent’s knowledge state in general. Therefore, epistemic agents can use their knowledge of margin for error at most once after a perceptual event, but (...) not more. This insight blocks a crucial step in Williamson’s original argument. Along the way, the value of standard epistemic logic for analyzing margin for error reasoning is challenged. (shrink)

The Surprise Exam Paradox is well-known: a teacher announces that there will be a surprise exam the following week; the students argue by an intuitively sound reasoning that this is impossible; and yet they can be surprised by the teacher. We suggest that a solution can be found scattered in the literature, in part anticipated by Wright and Sudbury, informally developed by Sorensen, and more recently discussed, and dismissed, by Williamson. In a nutshell, the solution consists in realising that the (...) teacher's announcement is a blindspot that can only be known if the week is at least 2 days long. Along the way, we criticise Williamson's own treatment of the paradox. In Williamson's view, the Surprise is similar to the Paradox of the Glimpse and, because of their similarities, both these paradoxes ought to receive a uniform treatment-one that involves locating an illicit application of the KK Principle. We argue that there's no deep analogy between the Surprise and the Glimpse and that, even if there were, the Surprise reasoning reaches a paradoxical conclusion before the KK Principle is used. Rather, in both the Surprise and the Glimpse, the blame should be put on other epistemic principles-respectively, a knowledge retention and a margin for error principle. (shrink)

This issue considers the ethics of a healthcare provider intervening into a patient’s genitalia, whether by means of cutting or surgery or by ‘mere’ touching/examination. Authors argue that the permissibility of such actions in the absence of a relevant medical emergency does not primarily turn on third-party judgments of expected levels of physical harm versus benefit, or on related notions such as extensiveness or invasiveness; rather, it turns on the patient’s own consent. To bolster this argument, attention is drawn to (...) the status of the genitals as ‘intimate’ anatomy—a status that is not fully erased by being in a medical context. In this editorial, we draw on the work of Talia Mae Bettcher on ‘intimate agency’ to explore why unconsented interventions into the genitalia may constitute a distinctive sort of personal violation compared to unconsented contact with various other parts of the human body. In their feature article, Marit van der Pijl and colleagues1 argue it is unethical for healthcare providers to perform unconsented episiotomies on persons in labour. In particular, they suggest that, outside of certain rare emergencies in which, for example, the person giving birth is incapacitated1 and the procedure cannot be delayed until consent becomes possible without introducing a significant risk of serious harm (call these ‘medically necessary’2 procedures), ‘presumed consent’ is the incorrect standard to apply. Instead, they stress that, especially when a proposed intervention involves a person’s genital, sexual or reproductive organs, the need to obtain their explicit consent in advance of proceeding must be honoured. As the authors note, the broader social significance of our genitalia—widely regarded as ‘private’ anatomy—is not erased by being in a medical context (see also 2–4). Boundaries must still be observed. Ethically, this ‘leaves a very small margin for error because invasion of these body parts …. (shrink)

Recently, Timothy Williamson has argued that considerations about margins of errors can generate a new class of cases where agents have justified true beliefs without knowledge. I think this is a great argument, and it has a number of interesting philosophical conclusions. In this note I’m going to go over the assumptions of Williamson’s argument. I’m going to argue that the assumptions which generate the justification without knowledge are true. I’m then going to go over some of the recent (...) arguments in epistemology that are refuted by Williamson’s work. And I’m going to end with an admittedly inconclusive discussion of what we can know when using an imperfect measuring device. (shrink)

How do we deal with difference personally, interpersonally, nationally? Can we weave a cohesive social fabric in a religiously plural society without suppressing differences? This collection of significant essays suggests that to truly honour differences in matters of faith and religion we must publicly exercise and celebrate them. The secular/sacred, public/private divisions long considered sacred in the West need to be dismantled if Canada (or any nation state) is to develop a genuine mosaic that embraces fundamental differences instead of a (...) melting pot that marginalizes. An ethics of difference starts with a recognition of difference, not as deviance or deficit that threatens but as otherness to connect with, cherish, and celebrate. The book begins with the suggestion that our inability to come to terms with social plurality is not fundamentally the fault of religious differences, and that a public/private split inadequately deals with matters of basic difference. It then explores how encouraging people to live out their respective faiths may open new possibilities for respectful, honourable, and just negotiations of contemporary dilemmas arising out of the multicultural fabric of Canadian life. Towards an Ethics of Community introduces readers to some of the most challenging and divisive dilemmas we face in this increasingly pluralistic, postmodern world — issues such as family and domestic violence, Aboriginal rights, homosexuality and public policy, and female genital mutilation. This is a book truly global in scope and significance. (shrink)

One of the problems when students go to university is that they are faced with insufficient skills (reading, summarizing and writing). These skills are not just an option for students – they are a necessity. One of these skills is text summarizing. Summarizing strategies may be called the gist of the literary text. Different summarization strategies may be required for different text types and lengths. The ability to summarize well means your reading comprehension and writing skill should be excellent. Summarization (...) is a high-level comprehension strategy which is effective in improving reading achievement and text summary quality.Several approaches have been developed to analyse summarizing skills which are required to teach and learn English at all levels especially at university level. The research was conducted among students of the second year English department at University of Vlora. The summaries reflect the major differences among the strategies used by skilled and unskilled students. The skilled students produce coherent linguistic and syntactic structures. Skilled (high-proficiency) students use semantic and prepositional phrases more than unskilled students (low-proficiency). Thus, the skilled students do not distort ideas of the original text but distort subject-verb order. When they summarize, we can easily distinguish the way in which they combine idea units across two or more paragraphs. The summaries reflect that students write very long sentences. The margin of errors is considerable due to the mother tongue influence and their level of English. (shrink)

Critical notice of Puddifoot, Katherine. 2021. How Stereotypes Deceive Us. NY: OUP.--------- -/- Kathy Puddifoot makes a compelling and enlightening case for a striking pair of claims: 1) false stereotypes sometimes steer us to the truth, while 2) true stereotypes often lead us into error. This is a wonderful book, a seamless integration of epistemology with ethics, of philosophy with social science, and of “mainstream” or “Western analytic” approaches with marginalized and underappreciated contributions from critical social traditions, especially black (...) feminism. The integrations are so seamless, in fact, as to give the reader the impression that Puddifoot is simply picking up conversations already underway. Instead, she has done a tremendous service in bringing representatives from wide-ranging, often-siloed disciplines into dialogue. Another virtue of Puddifoot’s book is how thoroughly it maps out the actual and possible views and logical spaces revolving around each topic she addresses. How Stereotypes Deceive Us could therefore be used to introduce budding epistemologists to the field, as it offers clear and careful explanations of leading approaches to a range of topics, including virtue epistemology, theory of mind, and more. (shrink)

According to a rich tradition in philosophy of action, intentional action requires practical knowledge: someone who acts intentionally knows what they are doing while they are doing it. Piñeros Glasscock argues that an anti-luminosity argument, of the sort developed in Williamson, can be readily adapted to provide a reductio of an epistemic condition on intentional action. This paper undertakes a rescue mission on behalf of an epistemic condition on intentional action. We formulate and defend a version of an epistemic condition (...) that is free from any luminosity commitments. While this version of an epistemic condition escapes reductio, it comes with substantive commitments of its own. In particular, we will see that it forces us to deny the existence of any essentially intentional actions. We go on to argue that this consequence should be embraced. On the resulting picture, intentional action is not luminous. But it still entails practical knowledge. (shrink)

Aus dem Inhalt: Views from the North: Hans Petter Graver: Law, Justice and the State: Nordic Perspectives u Jacob Dahl Rendtorff: The Danish Welfare State: Philosophical Ideals and Systemic Reality u Sigri!Dur *orgeirsdottir: Feminist Ethics and Feminist Politics u Kuellike Lengi: The Situation of Human Rights in Estonia u Einar Palsson: Pythagoras and Early Icelandic Law u Law, Discourse and Rationality: Mats Flodin: Internal and External Rationality of Legal Systems u Logi Gunnarsson: A Discourse About Discourse u Hjordi!s Hakonardottir: Legal (...) Language: A Tool of Justice u Ghita Holmstrom-Hintikka: On the Use of Expert Witness in Legal Reasoning and Inquiry u Law, State and Nation: Agust H. Ing*orsson: Democracy, Bureaucracy and Marginalization of the State u Aleksander Peczenik: Law-State, Legal Certainty and Legitimacy of Law u Ove K. Pedersen/Sverre Raffnsoe: Reorganizing Society u Juha Raikka: Mill on National Sentiment u Pall Skulason: Concepts of the State and Classes of Value u Problems of Law and Rights: Britt-Mari Blegvad: How to Cope With Uncertainty: Trust and Law u Jon Wetlesen: Animal Rights or Human Duties?. (shrink)

Error theorists hold that, although our first-order moral thought and discourse commits us to the existence of moral truths, there are no such truths. Holding this position in metaethics puts the error theorist in an uncomfortable position regarding first-order morality. When it comes to our pre-theoretic moral commitments, what should the error theorist think? What should she say? What should she do? I call this the ‘Now What’ Problem for error theory. This paper suggests a framework (...) for evaluating different approaches to the ‘Now What’ Problem, and goes on to evaluate the three most common responses to this problem. All three are found to have noteworthy problems. Finally, I present my own solution, and argue that it presents the most appealing solution to the ‘Now What’ Problem. (shrink)

This paper explores the principle that knowledge is fragile, in that whenever S knows that S doesn’t know that S knows that p, S thereby fails to know p. Fragility is motivated by the infelicity of dubious assertions, utterances which assert p while acknowledging higher-order ignorance whether p. Fragility is interestingly weaker than KK, the principle that if S knows p, then S knows that S knows p. Existing theories of knowledge which deny KK by accepting a Margin for (...) class='Hi'>Error principle can be conservatively extended with Fragility. (shrink)

Since its appearance over a decade ago, Timothy Williamson's anti-luminosity argument has come under sustained attack. Defenders of the luminous overwhelmingly object to the argument's use of a certain margin-for-error premise. Williamson himself claims that the premise follows easily from a safety condition on knowledge together with his description of the thought experiment. But luminists argue that this is not so: the margin-for-error premise either requires an implausible interpretation of the safety requirement on knowledge, or it requires other (...) equally implausible assumptions. In this paper I bolster the margin-for-error premise against these attacks by recasting Williamson's own two-part defence, the first part intended to work on the assumption that there is no constitutive connection between the phenomenal and the doxastic, and the second intended to work without this assumption. Pace various luminists, I argue that the appeals to safety needed for Williamson's two-part defence are plausible. I also argue that all that is needed to generate the margin-for-error premise from these safety conditions is an empirical assumption about the kinds of creatures we are: that is, creatures whose beliefs are structured by certain dispositions. By recasting the anti-luminosity argument in this way, we can understand what is really at stake in the debate about luminosity: that is, whether we are luminous. (shrink)

This paper is based on ethnographic research of data practices in a public health project called Weather Health and Air Pollution. I examine two different kinds of practices that make air pollution data, focusing on how they relate to particular modes of sensing and articulating air pollution. I begin by describing the interstitial spaces involved in making measurements of air pollution at monitoring sites and in the running of a computer simulation. Specifically, I attend to a shared dimension of these (...) practices, the checking of a numerical reading for error. Checking a measurement for error is routine practice and a fundamental component of making data, yet these are also moments of interpretation, where the form and meaning of numbers are ambiguous. Through two case studies of modelling and monitoring data practices, I show that making a ‘good’ measurement requires developing a feeling for the instrument–air pollution interaction in terms of the intended functionality of the measurements made. These affective dimensions of practice are useful analytically, making explicit the interaction of standardised ways of knowing and embodied skill in stabilising data. I suggest that environmental data practices can be studied through researchers’ materialisation of error, which complicate normative accounts of Big Data and highlight the non-linear and entangled relations that are at work in the making of stable, accurate data. (shrink)

Most of our knowledge is inexact, and known by us to be so. An example of such known inexactness will be described in some detail. The description seems to entail a contradiction. However, the paradoxical reasoning rests on an assumption. It will be suggested that the description is correct and this assumption false. Its failure will be explained by means of a picture of inexact knowledge in which the notion of a margin for error is central. This picture suggests (...) diagnoses of other paradoxical arguments: Surprise Examinations, backwards inductions about Iterated Prisoner's Dilemma, and the Heap. (shrink)

The Qualitative Thesis says that if you leave open P, then you are sure of if P, then Q just in case you are sure of the corresponding material conditional. We argue the Qualitative Thesis provides compelling reasons to accept a thesis that we call Conditional Locality, which says, roughly, the interpretation of an indicative conditional depends, in part, on the conditional’s local embedding environment. In the first part of the paper, we present an argument—due to Ben Holguín—showing that, without (...) Conditional Locality, the Qualitative Thesis is in tension with a margin for error principle on rational sureness. We show Conditional Locality reconciles the Qualitative Thesis with the margin for error principle. In the second part, we argue the full range of data supports what we call the Strong Qualitative Thesis. Without Conditional Locality, the Strong Qualitative Thesis has unacceptable consequences. But with Conditional Locality, it is tenable. (shrink)

The paper discusses some ways in which vagueness and its phenomena may be thought to impose certain limits on our knowledge and, more specifically, may be thought to bear on the traditional philosophical idea that certain domains of facts are luminous, i.e., roughly, fully open to our view. The discussion focuses on a very influential argument to the effect that almost no such interesting domains exist. Many commentators have felt that the vagueness unavoidably inherent in the description of the facts (...) that are best candidates for being luminous plays an illicit role in such argument. The paper centres around the idea that vagueness brings with itself the prima facie plausibility of soritical principles. Using the diagnostics of sharpenings, it is first pointed out that, despite certain considerations to the contrary, the margin‐for‐error principle required by the anti‐luminosity argument may well derive all of its plausibility from an underlying soritical principle. The notion of confidence that is relevant to the argument is then isolated and sharply distinguished from the notion of subjective probability. Against this background, it is argued that the reasoning about confidence involved in the argument in favour of the problematic margin‐for‐error principle is fallacious in the same way in which sorites reasoning is. This reveals the possibility of having reliable knowledge even at the penumbral limit with falsity, a possibility for which a concrete formal model is constructed. The model in turn permits a deeper appreciation of the role played in the dialectic by the distinction between confidence and subjective probability as well as by confidence requirements on knowledge. It is concluded that careful heeding of vagueness and its phenomena, far from forcing new and surprising limits on our knowledge, actually removes one of the main barriers – unreliability – often thought to stand in its way. (shrink)

Many of our sources of knowledge only afford us knowledge that is inexact. When trying to see how tall something is, or to hear how far away something is, or to remember how long something lasted, we may come to know some facts about the approximate size, distance or duration of the thing in question but we don’t come to know exactly what its size, distance or duration is. In some such situations we also have some pointed knowledge of how (...) inexact our knowledge is. That is, we can knowledgeably pinpoint some exact claims that we do not know. We show that standard models of inexact knowledge leave little or no room for such pointed knowledge. We devise alternative models that are not afflicted by this shortcoming. (shrink)

Air temperature prediction can play a significant role in studies related to climate change, radiation and heat flux estimation, and weather forecasting. This study applied and compared the outcomes of three advanced fuzzy inference models, i.e., dynamic evolving neural-fuzzy inference system, hybrid neural-fuzzy inference system, and adaptive neurofuzzy inference system for AT prediction. Modelling was done for three stations in North Dakota, USA, i.e., Robinson, Ada, and Hillsboro. The results reveal that FIS type models are well suited when handling highly (...) variable data, such as AT, which shows a high positive correlation with average daily dew point, total solar radiation, and negative correlation with average wind speed. At the Robinson station, DENFIS performed the best with a coefficient of determination of 0.96 and a modified index of agreement of 0.92, followed by ANFIS with R2 of 0.94 and md of 0.89, and HyFIS with R2 of 0.90 and md of 0.84. A similar result was observed for the other two stations, i.e., Ada and Hillsboro stations where DENFIS performed the best with R2: 0.953/0.960, md: 0.903/0.912, then ANFIS with R2: 0.943/0.942, md: 0.888/0.890, and HyFIS with R2: 0.908/0.905, md: 0.845/0.821, respectively. It can be concluded that all three models are capable of predicting AT with high efficiency by only using DP, TSR, and WS as input variables. This makes the application of these models more reliable for a meteorological variable with the need for the least number of input variables. The study can be valuable for the areas where the climatological and seasonal variations are studied and will allow providing excellent prediction results with the least error margin and without a huge expenditure. (shrink)

This paper supersedes an ealier version, entitled "A Non-Standard Semantics for Inexact Knowledge with Introspection", which appeared in the Proceedings of "Rationality and Knowledge". The definition of token semantics, in particular, has been modified, both for the single- and the multi-agent case.