The discussion about deep disagreement has gained significant momentum in the last several years. This discussion often relies on the intuition that deep disagreement is, in some sense, rationally irresolvable. In this paper, I will provide a theory of rationally irresolvable disagreement. Such a theory is interesting in its own right, since it conflicts with the view that rational attitudes and procedures are paradigmatic tools for resolving disagreement. Moreover, I will suggest replacing discussions about deep disagreement with an analysis of (...) rationally irresolvable disagreement, since this notion can be more clearly defined than deep disagreement and captures the basic intuitions underlying deep disagreement. I will first motivate this project by critically assessing the current debate about deep disagreement. I then detail the notions of rationality and resolvable disagreement which are crucial for a suitable theory of rationally irresolvable disagreement before sketching various instances of rationally irresolvable disagreement. Finally, I argue for replacing theories of deep disagreement with theories of rationally irresolvable disagreement, an approach that has significant advantages over existing theories of deep disagreement which focus on hinge propositions or fundamental epistemic principles. (shrink)

The current standard interpretation of Moore’s proof assumes Moore offers a solution to Kant’s famously posed problem of an external world, which Moore quotes at the start of his 1939 lecture “Proof of an External World.” As a solution to Kant’s problem, Moore’s proof fails utterly. Similarly, a second received interpretation imputes an aim of refuting metaphysical idealism that Moore’s proof does not at all achieve. This study departs from the received interpretations to credit Moore’s stated aim for the proof (...) Moore performed in his 1939 lecture that is to impose a counter-example to an explicitly stated presupposition of Kant’s famously posed problem of an external world. The outcome would therefore subvert Kant’s problem. There is not, however, any rival external world problem that Moore commends in place of Kant’s problem. (shrink)

We focus on Timothy Williamson’s recent attack on the epistemological significance of the a priori–a posteriori distinction, and offer an explanation of why, fundamentally, it does not succeed. We begin by setting out Williamson’s core argument, and some of the background to it and move to consider two lines of conciliatory response to it—conciliatory in that neither questions the central analogy on which Williamson's argument depends. We claim, setting aside a methodological challenge to which Williamson owes an answer, that no (...) satisfactory such reconciliation is in prospect. Rather, as we then argue, —and it is on this that we base our overall negative assessment of his argument—Williamson’s core analogy is flawed by an oversight. We conclude with some brief reflections on Williamson’s ideas about the imagination as a source of knowledge. Our principal conclusion is only that Williamson’s argument fails to perform as advertised. A constructive case for confidence, to the contrary, that the intuitive contrast between a priori and a posteriori reflects something of fundamental epistemological significance is prefigured in our final section, but will not be elaborated here. (shrink)

What is the metaphysical nature of perceptual experience? What evidence does experience provide us with? These questions are typically addressed in isolation. In order to make progress in answering both questions, perceptual experience needs to be studied in an integrated manner. I develop a unified account of the phenomenological and epistemological role of perceptual experience, by arguing that sensory states provide perceptual evidence due to their metaphysical structure. More specifically, I argue that sensory states are individuated by the perceptual capacities (...) employed and that there is an asymmetric dependence between their employment in perception and their employment in hallucination and illusion. Due to this asymmetric dependence, sensory states provide us with evidence. (shrink)

An argument is epistemically self-defeating when either the truth of an argument’s conclusion or belief in an argument’s conclusion defeats one’s justification to believe at least one of that argument’s premises. Some extant defenses of the evidentiary value of intuition have invoked considerations of epistemic self-defeat in their defense. I argue that there is one kind of argument against intuition, an unreliability argument, which, even if epistemically self-defeating, can still imply that we are not justified in thinking intuition has evidentiary (...) value. (shrink)

In the last few years there has been a resurgence of interest in Moore’s Proof of the existence of an external world, which is now often rendered as follows:1 (I) Here’s a hand (II) If there is a hand here, there is an external world Therefore (III) There is an external world The contemporary debate has been mostly triggered by Crispin Wright’s influential—conservative —“Facts and certainty” and further fostered by Jim Pryor’s recent—liberal—“What’s wrong with Moore’s argument?”.2 This debate is worth (...) surveying with care because—so I shall contend—it will help us see that, in fact, it allows for an important view that, so far, hasn’t been explicitly considered. The critical survey will be the task of the next two sections, while, in the remaining.. (shrink)

In the contemporary expanding literature on transmission failure and its connections with issues such as the Closure principle, the nature of perceptual warrant, Moore’s proof of an external world and the effectiveness of Humean scepticism, it has often been assumed that there is just one kind of it: the one made familiar by the writings of Crispin Wright and Martin Davies. Although it might be thought that one kind of failure is more than enough, Davies has recently challenged this view: (...) apparently, there are more ways in heaven and earth that warrant can fail to transmit across valid inference from one (set of) belief(s) to another, than have been dreamt of in philosophy so far. More specifically, Davies thinks that a second kind of transmission failure has to be countenanced. He connects each kind of failure of transmission of warrant with two different kinds of epistemic project, respectively, and with the exploration of whether the current dispute between conservatives such as Wright, and liberals such as Jim Pryor, on the nature of perceptual warrant, would have a bearing on them. I point out why Davies’s second kind of transmission failure is indeed no such thing. I then move on to canvass another kind of transmission failure, different from the one studied by both Wright and Davies, and dependent on an alternative conception of the structure of empirical warrants, which I dub “moderatism”. I then consider how this alternative notion of transmission failure fares with respect to Moore’s proof, its relationship with Wright’s kind of transmission failure and with the Closure principle. In closing, I defend it from criticisms that can be elicited from Pryor’s recent work. (shrink)

This Introduction to the special issue on “Skepticism and Justification” provides a background to the nine articles collected here and a detailed summary of each, which highlights their interconnections and relevance to the debate at the heart of the issue.

Our use of ‘I’, or something like it, is implicated in our self-regarding emotions, in the concern to survive, and so seems basic to ordinary human life. But why does that pattern of use require a referring term? Don't Lichtenberg's formulations show how we could have our ordinary pattern of use here without the first person? I argue that what explains our compulsion to regard the first person as a referring term is our ordinary causal thinking, which requires us to (...) find a persisting object as the mechanism that underpins the causal structure we naturally ascribe to the self. I thus argue against Peacocke's picture (2012), on which it's the cogito that explains one's knowledge of one's own existence. (shrink)

Once upon a time, coherentism was the dominant response to the regress problem in epistemology, but in recent decades the view has fallen into disrepute: now almost everyone is a foundationalist (with a few infinitists sprinkled here and there). In this paper, I sketch a new way of thinking about coherentism, and show how it avoids many of the problems often thought fatal for the view, including the isolation objection, worries over circularity, and concerns that the concept of coherence is (...) too vague or metaphorical for serious theoretical use. The key to my approach is to take a familiar tool from discussions of the regress problem -- namely, directed graphs depicting the support relations between beliefs -- and to use that tool in a more sophisticated manner than it is standardly employed. (shrink)

Fred Dretske notoriously claimed that knowledge closure sometimes fails. Crispin Wright agrees that warrant does not transmit in the relevant cases, but only because the agent must already be warranted in believing the conclusion in order to acquire her warrant for the premise. So the agent ends up being warranted in believing, and so knowing, the conclusion in those cases too: closure is preserved. Wright's argument requires that the conclusion's having to be warranted beforehand explains transmission failure. I argue that (...) it doesn't, and that the correct explanation does not imply that the agent will end up warranted in believing the conclusion when transmission fails. Those who agree that transmission does fail in those cases, therefore, might as well follow Dretske in denying knowledge closure too. (shrink)

A number of philosophers have recently claimed that unjustified beliefs can be defeaters. However these claims have been made in passing, occurring in the context of defenses of other theses. As a result, the claim that unjustified beliefs can be defeaters has been neither vigorously defended nor thoroughly explained. This paper fills that gap. It begins by identifying problems with the two most in-depth accounts of the possibility of unjustified defeaters due to Bergmann and Pryor. It then offers a revised (...) version of Pryor’s account. On this proposal, an unjustified belief can be a defeater if it is rational, all things considered. If a belief is rational, all things considered, it can require one to abandon other beliefs with which it conflicts—even if it is unjustified. Finally, this paper shows that the proposed account of unjustified defeaters is one that can and should be embraced by leading accounts of justified belief as diverse as reliabilism and evidentialism. (shrink)

Jurado: Mario Gómez-Torrente (presidente), Miguel Ángel Fernández Vargas (vocal), Santiago Echeverri Saldarriaga (secretario). [Graduado con Mención Honorífica.].

We have several intuitive paradigms of defeating evidence. For example, let E be the fact that Ernie tells me that the notorious pet Precious is a bird. This supports the premise F, that Precious can fly. However, Orna gives me *opposing* evidence. She says that Precious is a dog. Alternatively, defeating evidence might not oppose Ernie's testimony in that direct way. There might be other ways for it to weaken the support that Ernie's testimony gives me for believing F, without (...) the new evidence itself intuitively constituting reasons to believe one way or the other about Precious's flight ability. An example: Ursula tells me that Ernie has no idea what Precious's species is; he's just guessing. She may not herself want to or be in a position to weigh in about Precious's real species or flight ability. I call defeating evidence of this sort *undermining evidence. (shrink)

Dogmatism holds that an experience or seeming that p can provide prima facie immediate justification for believing p in virtue of its phenomenology. Dogmatism about perceptual justification has appealed primarily to proponents of representational theories of perceptual experience. Call dogmatism that takes perceptual experience to be representational "representational phenomenal dogmatism." As we show, phenomenal seemings play a crucial role in dogmatism of this kind. Despite its conventional appeal to representational theorists, dogmatism is not by definition committed to any particular view (...) of perceptual experience. Naive realists and disjunctivists who hold that perceptual experience is a perceptual relation of direct acquaintance can also endorse dogmatism. Indeed, we argue that they ought to do so. Otherwise, they cannot maintain that relationalism about perceptual experience has an epistemic advantage compared to the representational view. We then show that even if we grant that relationalism has this advantage, only dogmatism that takes perceptual experience to be representational can be extended to account for non-deductive inferential justification. As an account of the latter is required to avoid succumbing to skepticism, relationalism, we argue, does not have the epistemic advantage its defenders claim it has. (shrink)

Few philosophers believe that G. E. Moore's notorious proof of an external world can give us justification to believe that skepticism about perceptual beliefs is false. The most prominent explanation of what is wrong with Moore's proof—as well as some structurally similar anti-skeptical arguments—centers on conservatism: roughly, the view that someone can acquire a justified belief that p on the basis of E only if he has p-independent justification to believe that all of the skeptical hypotheses that undermine the support (...) lent by E to p are false. In this paper I argue that conservatism does not make trouble for Moore's proof. I do this by setting up a dilemma concerning the notion of "justification to believe" that figures in conservatism. On one understanding of justification to believe, conservatism is subject to obvious counterexamples. On another understanding of justification to believe, conservatism is consistent with Moore's "proof conferring justification upon its conclusion. Since these two understandings exhaust the logical space, the conservative indictment of Mooreanism fails. (shrink)

What does it mean to trust the results of a computer simulation? This paper argues that trust in simulations should be grounded in empirical evidence, good engineering practice, and established theoretical principles. Without these constraints, computer simulation risks becoming little more than speculation. We argue against two prominent positions in the epistemology of computer simulation and defend a conservative view that emphasizes the difference between the norms governing scientific investigation and those governing ordinary epistemic practices.

It can be easy to assume that since the “theist in the street” is unaware of any of the traditional arguments for theism, he or she is not in position to offer independent rational support for believing that God exists. I argue that that is false if we accept with William Alston that “manifestation beliefs” can enjoy rational support on the basis of suitable religious experiences. I make my case by defending the viability of a Moorean-style proof for theism—a proof (...) for the existence of God that parallels in structure G. E. Moore’s famous proof for the existence of the external world. I argue that this shows that even if the theist in the street has nothing to offer for helping to convince the religious sceptic, this needn’t entail that she cannot offer independent rational support in defense of her theistic belief. (shrink)

In this paper, I present and criticize a number of influential anti-skeptical strategies inspired by Wittgenstein’s remarks on ‘hinges’. Furthermore, I argue that, following Wittgen- stein’s analogy between ‘hinges’ and ‘rules of grammar’, we should be able to get rid of Cartesian skeptical scenarios as nonsensical, even if apparently intelligible, combinations of signs.

[full article, abstract in English; abstract in Lithuanian] Fred Dretske motivates his denial of epistemic closure by way of the thought that the warrant for the premises of a valid argument need not transfer to the argument’s conclusion. The failure-of-transfer-of-warrant strategy has also been used by advocates of epistemic closure as a foil to Michael McKinsey’s argument against the compatibility of first person authority and semantic externalism, and also to illuminate, more generally, why certain valid arguments appear ill-suited for the (...) purpose of establishing their conclusions. This paper takes re-examines some of the central attempts to explain transmission-failure, and a central line of objection to the strategy from Begging-the-Question theorists. The ultimate goal of this paper is to promote a decidedly Dretskean explanation of the unpersuasiveness of the said arguments. (shrink)

Even if our justified beliefs are closed under known entailment, there may still be instances of transmission failure. Transmission failure occurs when P entails Q, but a subject cannot acquire a justified belief that Q by deducing it from P. Paradigm cases of transmission failure involve inferences from mundane beliefs (e.g., that the wall in front of you is red) to the denials of skeptical hypotheses relative to those beliefs (e.g., that the wall in front of you is not white (...) and lit by red lights). According to the Bayesian explanation, transmission failure occurs when (i) the subject’s belief that P is based on E, and (ii) P(Q|E) P(Q). No modifications of the Bayesian explanation are capable of accommodating such cases, so the explanation must be rejected as inadequate. Alternative explanations employing simple subjunctive conditionals are fully capable of capturing all of the paradigm cases, as well as those missed by the Bayesian explanation. (shrink)

Contemporary debates concerning warrant transmission take for granted this thesis: when warrant transmission fails the argument fails. I challenge this thesis. An argument with conclusion C, addressed to subject S, can be cogent in the sense that recognition that the premises entail (or make highly likely) C can rationally foster in S the belief in C, without the warrant for C necessarily being gained (or reinforced) by such recognition. A key idea is to accept that some arguments should be understood (...) in a way that involves the abandonment of two characteristic idealizations imposed on rational thinkers by Bayesian modelling. (shrink)

That bootstrapping and Moorean reasoning fail to instantiate persuasive argumentation is an often informally presented but not systematically developed view. In this paper, I will argue that this unpersuasiveness is not determined by principles of justification transmission but by two straightforward principles of rationality, understood as a concept of internal coherence. First, it is rational for S to believe the conclusion of an argument because of the argument, only if S believes sufficiently many premises of the argument. Second, if S (...) doubts that a source O is reliable and believes that information i is delivered by O, then S rationally suspends judgment about the truth of i. This paper aims to accomplish two tasks. First, it provides a thorough analysis of why bootstrapping argumentation is not an instance of rational persuasion. Second, it contains a more general theory about preconditions and limits of persuasive argumentation. (shrink)

Take the following principle (or schema) as the focus of the ensuing discussion (“P” and “Q” are placeholders for propositions): 1 (Closure) If one knows P and competently deduces Q from P, thereby coming to believe Q, while retaining one's knowledge that P, one comes to know that Q. My strategy in outline: first, I want to set out Fred Dretske's classic challenge to (Closure) – a challenge which began in 1970–1971. Then I want to consider a specific, recent counter‐challenge (...) to Dretske's challenge to (Closure) mounted by John Hawthorne, and to defend Dretske's challenge from Hawthorne's counter‐challenge. Doing this is not to invalidate (Closure). In this regard my conclusions are modest: Dretske's challenge to (Closure) is – or, better: can be made – sophisticated and, so far, unmet. (shrink)

My aim in this paper is to assess the viability of a perceptual epistemology based on what Anil Gupta calls the “hypothetical given”. On this account, experience alone yields no unconditional entitlement to perceptual beliefs. Experience functions instead to establish relations of rational support between what Gupta calls “views” and perceptual beliefs. I argue that the hypothetical given is a genuine alternative to the prevailing theories of perceptual justification but that the account faces a dilemma: on a natural assumption about (...) the epistemic significance of support relations, any perceptual epistemology based on the hypothetical given results in either rationalism or skepticism. I conclude by examining the prospects for avoiding the dilemma. One option is to combine the hypothetical given with a form of holism. Another is to combine the view with a form of hinge epistemology. But neither offers a simple fix. (shrink)

According to a widely shared generic conception of inferential justification—‘the standard conception’—an agent is inferentially justified in believing that p only if she has antecedently justified beliefs in all the non-redundant premises of a good argument for p. This conception tends to serve as the starting-point in contemporary debates about the nature and scope of inferential justification: as neutral common ground between various competing, more specific, conceptions. But it’s a deeply problematic starting-point. This paper explores three questions that haven’t been (...) given the attention they deserve, that complicate the application of the standard conception to cases, and that reveal it to be underspecified at the core—in ways that aren’t resolved but inherited by more specific (extant) versions of it. The goal isn’t to answer the questions, but to articulate them, explain what turns on them, and invite a critical re-examination of the standard conception. (shrink)

Epistemological disjunctivists make appeal to Moorean-style anti-skeptical arguments. It is often held that one problem with using Moorean-style arguments in the context of a response to skepticism is that such arguments are subject to a kind of epistemic circularity. The specific kind of epistemic failure involved has come to be known as a failure of warrant transmission. It would likely pose a problem for the anti-skeptical ambitions of the epistemological disjunctivist if his version of the Moorean-style argument failed to transmit (...) warrant; but no epistemological disjunctivist has offered an argument to show that this is not so. In this paper, I fill the gap by arguing that warrant transmits across epistemological disjunctivist Moorean-style arguments. (shrink)

In this paper, I examine Crispin Wright’s most recent attempt to introduce a diagnostic tool for predicting failures of warrant transmission, the so-called ‘Revised Template’. I show that the Revised Template does not, in fact, generate the predictions about warrant transmission failure that Wright thinks it does. I argue that the failure lies, in large part, with the definition of the technical notion ‘presupposition’ which the Revised Template deploys. Through a consideration of Wright’s own ‘general motivation’ for the Revised Template, (...) I extract an alternative characterization of ‘presupposition’ and use this to fuel a diagnostic tool for predicting failures of warrant transmission which, I believe, is both more faithful to Wright’s own general motivating remarks and more successful in predicting failures of warrant transmission than the Revised Template. (shrink)

Modern-day heirs of the Cartesian revolution have been fascinated by the thought that one could utilize certain hypotheses – that one is dreaming, deceived by an evil demon, or a brain in a vat – to argue at one fell swoop that one does not know, is not justified in believing, or ought not believe most if not all of what one currently believes about the world. A good part of the interest and mystique of these discussions arises from the (...) contention that the seeds of such arguments lie in our ordinary epistemic practices, so that external world skepticism can arise “from within”. But is this contention correct? I doubt it. Taking skepticism seriously requires that we address this question head on. To do so, I will approach skeptical arguments from a certain vantage point. I will try to stand, as far as possible, with both feet squarely in ordinary life. I will start out with all of our ordinary commitments about what is the case, about what we know or have reason to believe, about when someone knows, is justified, or has good reason to believe something, and about how one should proceed in deciding what to believe. My question, then, will be this. From within that vantage point can I somehow be moved in a reasonable way to accept the conclusion that I know far less about the world around me than I thought, or that epistemically speaking, I really ought not believe much of what I have believed about the world around me? In order for such movement to take place, I will have to find reason from within my ordinary standpoint to discount or reject much of what I ordinarily accept. And of course, that reason will have to come from some.. (shrink)

This study provides a critical appraisal of Duncan Pritchard’s argument to the effect that ability to preserve certain eminently plausible transmission and/or closure principles for knowledge serves as a powerful adequacy test on alternative accounts of so-called Wittgensteinian certainties or hinge commitments. I argue that Pritchard fails to establish this claim—the transmission test does not favour his favourite conception over alternative conceptions premised on the idea that hinge commitments are not supportable via evidential-cognitive routes.

A prima facie plausible and widely held view in epistemology is that the epistemic standards governing the acquisition of testimonial knowledge are stronger than the epistemic standards governing the acquisition of perceptual knowledge. Conservatives about testimony hold that we need prior justification to take speakers to be reliable but recognise that the corresponding claim about perception is practically a non-starter. The problem for conservatives is how to establish theoretically significant differences between testimony and perception that would support asymmetrical epistemic standards. (...) In this paper I defend theoretical symmetry of testimony and perception on the grounds that there are no good reasons for taking these two belief forming methods to have significant theoretical differences. I identify the four central arguments in defence of asymmetry and show that in each case either they fail to establish the difference that they purport to establish or they establish a difference that is not theoretically significant. (shrink)

Arguments from "easy knowledge" are meant to refute a class of epistemological views, including foundationalism about perceptual knowledge. I present arguments from easy knowledge in their strongest form, and explain why other formulations in the literature are inferior. I criticize two features of Stewart Cohen's presentation, namely his focus on knowing that one's faculties are reliable, and his use of a Williamson-style closure principle. Rather, the issue around easy knowledge must be understood using a notion of epistemic priority. Roger White's (...) presentation is contaminated by the so-called lottery puzzle, which is best kept separate. Distinguishing basic from non-basic visual contents limits the force of the examples discussed by Cohen, White, and Crispin Wright. Finally, I present a new strategy for resisting even the best-formulated arguments from easy knowledge. (shrink)

This paper explains what’s wrong with a Hume-inspired argument for skepticism about induction. Hume’s argument takes as a premise that inductive reasoning presupposes that the future will resemble the past. I explain why that claim is not plausible. The most plausible premise in the vicinity is that inductive reasoning from E to H presupposes that if E then H. I formulate and then refute a skeptical argument based on that premise. Central to my response is a psychological explanation for how (...) people judge that if E then H without realizing that they thereby settled the matter rationally. (shrink)

A sensible epistemologist may not see how she could know that she is not a brain in a vat ; but she doesn’t panic. She sticks with her empirical beliefs, and as that requires, believes that she is not a BIV. (She does not inferentially base her belief that she is not a BIV on her empirical knowledge—she rejects that ‘Moorean’ response to skepticism.) Drawing on the psychological literature on metacognition, I describe a mechanism that’s plausibly responsible for a sensible (...) epistemologist coming to believe she is not a BIV. I propose she thereby knows that she is not a BIV. The particular belief-forming mechanism employed explains why she overlooks this account of how she knows she is not a BIV, making it seem that there is no way for her to know it. I argue this proposal satisfactorily resolves the skeptical puzzle. (shrink)

Epistemic closure under known implication is the principle that knowledge of "p" and knowledge of "p implies q", together, imply knowledge of "q". This principle is intuitive, yet several putative counterexamples have been formulated against it. This paper addresses the question, why is epistemic closure both intuitive and prone to counterexamples? In particular, the paper examines whether probability theory can offer an answer to this question based on four strategies. The first probability-based strategy rests on the accumulation of risks. The (...) problem with this strategy is that risk accumulation cannot accommodate certain counterexamples to epistemic closure. The second strategy is based on the idea of evidential support, that is, a piece of evidence supports a proposition whenever it increases the probability of the proposition. This strategy makes progress and can accommodate certain putative counterexamples to closure. However, this strategy also gives rise to a number of counterintuitive results. Finally, there are two broadly probabilistic strategies, one based on the idea of resilient probability and the other on the idea of assumptions that are taken for granted. These strategies are promising but are prone to some of the shortcomings of the second strategy. All in all, I conclude that each strategy fails. Probability theory, then, is unlikely to offer the account we need. (shrink)

According to the principle of epistemic closure, knowledge is closed under known implication. The principle is intuitive but it is problematic in some cases. Suppose you know you have hands and you know that ‘I have hands’ implies ‘I am not a brain-in-a-vat’. Does it follow that you know you are not a brain-in-a-vat? It seems not; it should not be so easy to refute skepticism. In this and similar cases, we are confronted with a puzzle: epistemic closure is an (...) intuitive principle, but at times, it does not seem that we know by implication. In response to this puzzle, the literature has been mostly polarized between those who are willing to do away with epistemic closure and those who think we cannot live without it. But there is a third way. Here I formulate a restricted version of the principle of epistemic closure. In the standard version, the principle can range over any proposition; in the restricted version, it can only range over those propositions that are within the limits of a given epistemic inquiry and that do not constitute the underlying assumptions of the inquiry. If we adopt the restricted version, I argue, we can preserve the advantages associated with closure, while at the same time avoiding the puzzle I’ve described. My discussion also yields an insight into the nature of knowledge. I argue that knowledge is best understood as a topic-restricted notion, and that such a conception is a natural one given our limited cognitive resources. (shrink)

Extended Rationality: A Hinge Epistemology provides a novel account of the structure of epistemic justification. Its central claim builds upon Wittgenstein's idea in On Certainty that epistemic justifications hinge on some basic assumptions and that epistemic rationality extends to these very hinges. It exploits these ideas to address major problems in epistemology, such as the nature of perceptual justifications, external world skepticism, epistemic relativism, the epistemic status of basic logical laws, of the Principle of the Uniformity of Nature, of our (...) belief in the existence of the past and of other minds, and the nature of testimonial justification. Along the way, further technical issues, such as the scope of the Principle of Closure of epistemic operators under known entailment, the notion of transmission failure, and the existence of entitlements are addressed in new and illuminating ways. (shrink)

In this paper, I present and criticize a number of influential contemporary anti-skeptical strategies inspired by G.E. Moore’s “proof of an external world”. I argue that these accounts cannot represent a valid response to skeptical worries. Furthermore, drawing on Wittgenstein’s criticisms of Moore, I argue that Radical skeptical hypotheses should be considered nonsensical combinations of signs, excluded from our epistemic practices.

Conventional accounts of epistemic opacity, particularly those that stem from the definitive work of Paul Humphreys, typically point to limitations on the part of epistemic agents to account for the distinct ways in which systems, such as computational methods and devices, are opaque. They point, for example, to the lack of technical skill on the part of an agent, the failure to meet standards of best practice, or even the nature of an agent as reasons why epistemically relevant elements of (...) a process may be inaccessible. In this paper I argue that there are certain instances of epistemic opacity— particularly in computational methods such a computer simulations and machine learning processes—that do not arise from, are not responsive to, and are therefore not explained by the epistemic limitations of an agent. I call these instances agent-neutral and agent-independent instances of epistemic opacity respectively. As a result, I also argue that conventional accounts of epistemic opacity offer a limited understanding of the full spectrum of kinds and sources of epistemic opacity, particularly of the kind found in computational methods. In particular, as I will show below, the limitations of these accounts are reflected in the way they fail to provide satisfactory explanations when faced with certain instances of opacity. (shrink)