Support is canvassed for a novel solution to the sceptical problem regarding our knowledge of the external world. Key to this solution is the claim that what initially looks like a single problem is in fact two logically distinct problems. In particular, there are two putative sceptical paradoxes in play here, which each trade on distinctive epistemological theses. It is argued that the ideal solution to radical scepticism would thus be a biscopic proposal—viz., a two-pronged, integrated, undercutting treatment of both (...) putative sceptical paradoxes. A particular biscopic proposal is then explored which brings together two apparently opposing anti-sceptical theses: he Wittgensteinian account of the structure of rational evaluation and epistemological disjunctivism. It is argued that each proposal enables us to gain a purchase on one, but only one, aspect of the two-sided sceptical problem. Furthermore, it is argued that these proposals are not only compatible positions, but also mutually supporting and advanced in the same undercutting spirit. A potential cure is thus offered for epistemic angst. (shrink)

Does G. E. Moore know that he has hands? Yes, says the dogmatist: Moore’s hands are right before his eyes. No, says the skeptic: for all Moore knows he could be a brain-in-a-vat. Yes and no, says the contrastivist: yes, Moore knows that he has hands rather than stumps; but no, Moore does not know that he has hands rather than vat-images of hands. The dogmatist and the skeptic suppose that knowledge is a binary, categorical relation: s knows that p. (...) The contrastivist says that knowledge is a ternary, contrastive relation: s knows that p rather than q. (shrink)

The aim of this paper is to analyse and develop how scepticism becomes an intelligible question starting from requirements that epistemologists themselves aim to endorse. We argue for and defend the idea that the root of scepticism is the underdetermination principle by articulating its specificitya respectable epistemic principle and by defending it against objections in current literature. This engagement offers a novel understanding of underdetermination-based scepticism. While most anti-sceptical approaches challenge scepticism by understanding it as postulating uneliminated scenarios of mass (...) deception, or as endorsing unnatural epistemic requirements, we argue here that both contentions are mistaken. Underdetermination-based scepticism targets our beliefs by issuing a genuine question about the rational support they enjoy. If we cannot establish that the sources of our beliefs provide them the required epistemic merit and authority, they lack non-arbitrary grounds. This has a sizable impact on what constitutes a satisfactory anti-sceptical strategy. Strategies that merely focus on the scenario-based aspect of scepticism, or on the truth-functional evaluation of our beliefs, are shown to miss the mark of the sceptical threat. The proposed analysis ultimately provides a shift in perspective concerning the character and reach of philosophical doubt. (shrink)

Abductivists claim that explanatory considerations (e.g., simplicity, parsimony, explanatory breadth, etc.) favor belief in the external world over skeptical hypotheses involving evil demons and brains in vats. After showing how most versions of abductivism succumb fairly easily to obvious and fatal objections, I explain how rationalist versions of abductivism can avoid these difficulties. I then discuss the most pressing challenges facing abductivist appeals to the a priori and offer suggestions on how to overcome them.

It is nowadays taken for granted that the core radical sceptical arguments all pivot upon the principle that the epistemic operator in question is 'closed' under known entailments. Accordingly, the standard anti-sceptical project now involves either denying closure or retaining closure by amending how one understands other elements of the sceptical argument. However, there are epistemic principles available to the sceptic which are logically weaker than closure but achieve the same result. Accordingly the contemporary debate fails to engage with the (...) sceptical problem in its strongest form. (shrink)

A skeptic claims that I do not have knowledge of the external world. It has been thought that the skeptic reaches this conclusion because she employs unusually stringent standards for knowledge. But the skeptic does not employ unusually high standards for knowledge. Rather, she employs unusually restrictive standards of evidence. Thus, her claim that we lack knowledge of the external world is supported by considerations that would equally support the claim that we lack evidence for our beliefs about the external (...) world. These considerations do not threaten the truth of our ordinary attributions of evidence, however, for such attributions are context-sensitive in their semantics. It is argued that this solution to the problem of the external world enjoys all of the benefits, and suffers none of the problems, of other solutions to the problem of the external world. (shrink)

Conceptual Engineering alleges that philosophical problems are best treated via revising or replacing our concepts (or words). The goal here is not to defend Conceptual Engineering but rather show that it can (and should) invoke Neutralism—the broad view that philosophical progress can take place when (and sometimes only when) a thoroughly neutral, non-specific theory, treatment, or methodology is adopted. A neutralist treatment of one form of skepticism is used as a case study and is compared with various non-neutral rivals. Along (...) the way, a new taxonomy for paradox is proposed. (shrink)

The sceptic about the external world presents us with a paradox: an apparently acceptable argument for an apparently unacceptable conclusion—that we do not know anything about the external world. Some paradoxes, for instance the liar and the sorites, are very hard. The defense of a purported solution to either of these two inevitably deploys the latest in high-tech philosophical weaponry. On the other hand, some paradoxes are not at all hard, and may be resolved without much fuss. They do not (...) contain profound lessons about the human condition. Where should we place the sceptical paradoxes? (shrink)

Deepfakes are audio, video, or still-image digital artifacts created by the use of artificial intelligence technology, as opposed to traditional means of recording. Because deepfakes can look and sound much like genuine digital recordings, they have entered the popular imagination as sources of serious epistemic problems for us, as we attempt to navigate the increasingly treacherous digital information environment of the internet. In this paper, I attempt to clarify what epistemic problems deepfakes pose and why they pose these problems, by (...) drawing parallels between recordings and our own senses as sources of evidence. I show that deepfakes threaten to undermine the status of digital recordings as evidence. The existence of deepfakes thus encourages a kind of skepticism about digital recordings that bears important similarities to classic philosophical skepticism concerning the senses. However, the skepticism concerning digital recordings that deepfakes motivate is also importantly different from classical skepticism concerning the senses, and I argue that these differences illuminate some possible strategies for solving the epistemic problems posed by deepfakes. (shrink)

It is widely thought that if knowledge requires sensitivity, knowledge is not closed because sensitivity is not closed. This paper argues that there is no valid argument from sensitivity failure to non-closure of knowledge. Sensitivity does not imply non-closure of knowledge. Closure considerations cannot be used to adjudicate between safety and sensitivity accounts of knowledge.

According to epistemological disjunctivism (ED), in paradigmatic cases of perceptual knowledge, a subject, S, has perceptual knowledge that p in virtue of being in possession of reasons for her belief that p which are both factive and reflectively accessible to S. It has been argued that ED is better placed than both knowledge internalism and knowledge externalism to undercut underdetermination-based skepticism. I identify several principles that must be true if ED is to be uniquely placed to attain this goal. After (...) that, I use those principles to formulate a diachronic skeptical argument. This argument yields the counterintuitive conclusion that understanding a global skeptical hypothesis is all it takes for a rational subject to lose all her perceptual knowledge of the world. Next, I show that a popular Austinian move must reject one or another of the principles that underlie ED. I close by delineating a novel strategy that can block the diachronic skeptical argument while preserving all the principles. The key idea is that perceptual knowledge is grounded in primitive, perceptual and recognitional abilities. This view sheds new light on some puzzling features of global skepticism that have been noted by Descartes and Hume, among others. (shrink)

Moral skeptics maintain that we do not have moral knowledge. Traditionally they haven’t argued via skeptical hypotheses like those provided by perceptual skeptics about the external world, such as Descartes’ deceiving demon. But some believe this can be done by appealing to hypotheses like moral nihilism. Moreover, some claim that skeptical hypotheses have special force in the moral case. But I argue that skeptics have failed to specify an adequate skeptical scenario, which reveals a general lesson: such arguments are not (...) a promising avenue for moral skeptics to take. They’re ultimately weaker when applied to morality compared to perception. (shrink)

Recent literature in epistemology has focused on the following argument for skepticism (SA): I know that I have two hands only if I know that I am not a handless brain in a vat. But I don't know I am not a handless brain in a vat. Therefore, I don't know that I have two hands. Part I of this article reviews two responses to skepticism that emerged in the 1980s and 1990s: sensitivity theories and attributor contextualism. Part II considers (...) the more recent ‘neo-Moorean’ response to skepticism and its development in ‘safety’ theories of knowledge. Part III argues that the skeptical argument set out in SA is not of central importance. Specifically, SA is parasitic on skeptical reasoning that is more powerful and more fundamental than that displayed by SA itself. Finally, Part IV reviews a Pyrrhonian argument for skepticism that is not well captured by SA, and considers a promising strategy for responding to it. (shrink)

We report the results of four empirical studies designed to investigate the extent to which an epistemic closure principle for knowledge is reflected in folk epistemology. Previous work by Turri (2015a) suggested that our shared epistemic practices may only include a source-relative closure principle—one that applies to perceptual beliefs but not to inferential beliefs. We argue that the results of our studies provide reason for thinking that individuals are making a performance error when their knowledge attributions and denials conflict with (...) the closure principle. When we used research materials that overcome what we think are difficulties with Turri’s original materials, we found that participants did not reject closure. Furthermore, when we presented Turri’s original materials to non-philosophers with expertise in deductive reasoning (viz., professional mathematicians), they endorsed closure for both perceptual and inferential beliefs. Our results suggest that an unrestricted closure principle—one that applies to all beliefs, regardless of their source—provides a better model of folk patterns of knowledge attribution than a source-relative closure principle. (shrink)

Perhaps the most dominant anti‐sceptical proposal in recent literature –advanced by such figures as Stewart Cohen, Keith DeRose and David Lewis –is the contextualist response to radical scepticism. Central to the contextualist thesis is the claim that, unlike other non‐contextualist anti‐sceptical theories, contextualism offers a dissolution of the sceptical paradox that respects our common sense epistemological intuitions. Taking DeRose's view as representative of the contextualist position, it is argued that instead of offering us an intuitive response to scepticism, contextualism is (...) actually committed to a revisionist stance as regards our everyday usage of epistemic terms. In particular, it is argued that the thesis fails to present a satisfactory explication of a notion –that of‘epistemic descent’– that is pivotal to the anti‐sceptical import of the account. On the positive side, however, it is claimed that although the contextualist response to scepticism is ultimately unsatisfying, DeRose's theory does contain within it the framework for a completely different ‐ and far more persuasive ‐ account of the‘phenomenology’of scepticism which runs along non‐contextualist lines. (shrink)

Cartesian skepticism about epistemic justification (‘skepticism’) is the view that many of our beliefs about the external world – e.g., my current belief that I have hands – aren’t justified. I examine the two most influential arguments for skepticism – the Closure Argument and the Underdetermination Argument – from an evidentialist perspective. For both arguments it is clear which premise the anti-skeptic must deny. The Closure Argument, I argue, is the better argument in that its key premise is weaker than (...) the Underdetermination Argument’s key premise. However, it’s also likely that the motivation for accepting both key premises is exactly the same. So there may be a sense in which both arguments provide exactly the same motivation for skepticism. Then I argue that if I I’m right about what the motivation for accepting the arguments’ key premises is, then neither argument succeeds in providing a good reason to accept skepticism. I conclude by explaining why I think epistemologists are right to expend a lot of time and effort on refuting these arguments, even if neither argument provides any motivation for skepticism. (shrink)

On a common view of scenario-based sceptical arguments sceptical scenarios are error-possibilities, i.e. their point is to introduce the possibility of having only false beliefs. However, global error is impossible for purely logical/conceptual reasons: Even if one’s beliefs are consistent, the negations of one’s beliefs need not be consistent as well. My paper deals with the question of what the consequences of this result are. Two attempts at repairing scenario-based sceptical arguments within the framework of understanding sceptical scenarios as error-possibilities (...) are found wanting. Instead, what should be given up is the assumption that sceptical scenarios are error-possibilities. What is thought-provoking about the scenario of the brain in a vat is not that none of its empirical beliefs are true, but that all of its empirical beliefs fall short of knowledge at the same time. Hence, sceptical scenarios are not error-possibilities, but ignorance possibilities. If this is so, both the closure argument and the underdetermination argument commit a subtle mistake and should be replaced by slightly different arguments. The principle of excluded ignorance-possibilities turns out to be an epistemological principle that is faithful to scepticism’s tenets without misinterpreting sceptical scenarios as error-possibilities. (shrink)

Epistemologists understand radical skepticism as arising from two principles: Closure and Underdetermination. Both possess intuitive prima facie support for their endorsement. Understanding how they engender skepticism is crucial for any reasonable anti-skeptical attempt. The contemporary discussion has focused on elucidating the relationship between them to ascertain whether they establish distinct skeptical questions and which of the two constitutes the ultimately fundamental threat. Major contributions to this debate are due to Brueckner, Cohen, and Pritchard. This contribution aims at defending Brueckner’s contention (...) that underdetermination expresses the fundamental skeptical threat and that the closure-based argument can ultimately be reduced to it, at least concerning skeptical contexts. This will be achieved by undermining Cohen’s objections to Brueckner on both counts. Cohen’s argument endorses a picture of evidential underdetermination, which, while apt for non-skeptical contexts, cannot be applied to radical skepticism. A comparison with a case of scientific underdetermination is developed to argue for this idea. Our argument is then applied to the principle equivalence issue and to objections against it. It is then shown how this analysis possesses a distinctive effect on our understanding of the skeptical threat and the assessment of successful anti-skeptical strategies. (shrink)

Some philosophers argue that we are justified in rejecting skepticism because it is explanatorily inferior to more commonsense hypotheses about the world. Focusing on the work of Jonathan Vogel, I show that this “abductivist” or “inference to the best explanation” response rests on an impoverished explanatory framework which ignores the explanatory gap between an object's having certain properties and its appearing to have those properties. Once this gap is appreciated, I argue, the abductivist strategy is defeated.

A certain interpretation of Wittgenstein’s remarks in On Certaintyadvanced by such figures as Hilary Putnam, Peter Strawson, Avrum Stroll and Crispin Wrighthas become common currency in the recent literature. In particular, this reading focuses upon the supposed anti-sceptical import of the Wittgensteinian notion of a “hinge” proposition. In this paper it is argued that this interpretation is flawed both on the grounds that there is insufficient textual support for this reading and that, in any case, it leads to unpalatable philosophical (...) problems. Moreover, it is claimed that the popularity of this construal of On Certainty in the contemporary debate reflects an implicit commitment to the contentious doctrine of epistemological internalism. Nevertheless, it is argued that, suitably modified along the epistemologically externalist lines suggested by Michael Williams, one might be able to resurrect a viable anti-sceptical hinge proposition thesis. Furthermore, it is claimed that such a conception of the notion also receives some, albeit inconclusive, textual support from On Certainty. (shrink)

This paper considers two novel Bayesian responses to a well-known skeptical paradox. The paradox consists of three intuitions: first, given appropriate sense experience, we have justification for accepting the relevant proposition about the external world; second, we have justification for expanding the body of accepted propositions through known entailment; third, we do not have justification for accepting that we are not disembodied souls in an immaterial world deceived by an evil demon. The first response we consider rejects the third intuition (...) and proposes an explanation of why we have a faulty intuition. The second response, which we favor, accommodates all three intuitions; it reconciles the first and the third intuition by the dual component model of justification, and defends the second intuition by distinguishing two principles of epistemic closure. (shrink)

Anthony Brueckner argues for a strong connection between the closure and the underdetermination argument for scepticism. Moreover, he claims that both arguments rest on infallibilism: In order to motivate the premises of the arguments, the sceptic has to refer to an infallibility principle. If this were true, fallibilists would be right in not taking the problems posed by these sceptical arguments seriously. As many epistemologists are sympathetic to fallibilism, this would be a very interesting result. However, in this paper I (...) will argue that Brueckner’s claims are wrong: The closure and the underdetermination argument are not as closely related as he assumes and neither rests on infallibilism. Thus even a fallibilist should take these arguments to raise serious problems that must be dealt with somehow. (shrink)

In his recent work, Duncan Pritchard defends a novel Wittgensteinian response to the problem of radical scepticism. The response makes essential use of a form of non-epistemicism about the nature of hinge commitments. According to non-epistemicism, hinge commitments cannot be known or grounded in rational considerations, such as reasons and evidence. On Pritchard’s version of non-epistemicism, hinge commitments express propositions but cannot be believed. This is the non-belief theory of hinge commitments. One of the main reasons in favour of NBT (...) over rival anti-sceptical Wittgensteinian views is that it has less theoretical costs and revisionary consequences than its rivals. In this paper, I argue that NBT fares at least as bad as its rivals in terms of its theoretical costs and revisionism. In particular, I argue that NBT is inconsistent with certain cases of philosophical disagreement; that it faces worries with mental-state scepticism; and that it faces difficulties in explaining how we can represent ourselves as committed to hinge commitments. (shrink)

I focus on a key argument for global external world scepticism resting on the underdetermination thesis: the argument according to which we cannot know any proposition about our physical environment because sense evidence for it equally justifies some sceptical alternative (e.g. the Cartesian demon conjecture). I contend that the underdetermination argument can go through only if the controversial thesis that conceivability is per se a source of evidence for metaphysical possibility is true. I also suggest a reason to doubt that (...) conceivability is per se a source of evidence for metaphysical possibility, and thus to doubt the underdetermination argument. (shrink)

In this paper, I offer reasons for thinking that two prominent sceptical arguments in the literature – the underdetermination-based sceptical argument and the closure-based sceptical argument – are less philosophically interesting than is commonly supposed. The underdetermination-based argument begs the question against a non-sceptic and can be dismissed with little fanfare. The closure-based argument, though perhaps not question-begging per se, does rest upon contentious assumptions that a non-sceptic is under no pressure to accept.

Those of us who have followed Fred Dretske's lead with regard to epistemic closure and its impact on skepticism have been half-wrong for the last four decades. But those who have opposed our Dretskean stance, contextualists in particular, have been just wrong. We have been half-right. Dretske rightly claimed that epistemic status is not closed under logical implication. Unlike the Dretskean cases, the new counterexamples to closure offered here render every form of contextualist pro-closure maneuvering useless. But there is a (...) way of going wrong under Dretske's lead. As the paper argues, Cartesian skepticism thrives on closure failure in a way that is yet to be acknowledged in the literature. The skeptic can make do with principles which are weaker than the familiar closure principles. But I will further claim that this is only a momentary reprieve for the skeptic. As it turns out, one of the weaker principles on which a skeptical modus tollens must rest can be shown false. (shrink)

In this paper I develop an account of petitio principii (the fallacy sometimes also called ‘vicious circularity’, or ‘begging the question’) which has two crucial features: it employs the notion of doxastic justification, and it takes circularity to be relative to an evidential state. According to my account, an argument will be circular relative to an evidential state if and only if having doxastic justification for the conclusion is necessary, for a subject in that evidential state, to have doxastic justification (...) for the premisses. I compare the account to some existing ones, and claim some advantages. I then rebut an objection which threatens to undermine the importance of one of those advantages. This account seems to shed new light on the old problem of characterizing petitio principii. It avoids the two obvious problems which any account of this phenomenon must face: being too narrow, for example by leaving out all arguments in which the conclusion does not appear among the premisses, and being too wide, making all valid arguments circular. (shrink)

Stephen Schiffer has argued that contextualist solutions to skepticism rest on an implausible "error theory" concerning our own semantic intentions. Similar arguments have recently been offered also by Thomas Hofweber and Patrick Rysiew. I attempt to show how contextualists can rebut these arguments. The kind of self-knowledge that contextualists are committed to denying us is not a kind of self-knowledge that we need, nor is it a kind of self-knowledge that we can plausibly be thought to possess.

In this essay I defend a solution to a skeptical paradox. The paradox I focus on concerns epistemic justification (rather than knowledge), and skeptical scenarios that entail that most of our ordinary beliefs about the external world are false. This familiar skeptical paradox hinges on a “closure” principle. The solution is to restrict closure, despite its first appearing as a fully general principle, so that it can no longer give rise to the paradox. This has some extra advantages. First, it (...) suggests a general strategy that provides solutions to other versions of the paradox, not just those that depend on closure. Second, it clarifies the relation between the paradox and other kinds of skeptical problem. (shrink)

In contemporary epistemology, sceptical arguments are motivated either by the closure principle or the underdetermination principle. Therefore, it is very important to figure out the structure of the sceptical argument before coming up with an anti-sceptic strategy. With a review of the debate on the relationship between the two principles from Anthony Brueckner to Kevin McCain, it is argued that while maintaining the weak closed justification , closure and underdetermination are not logically equivalent. As a result, two independent responses are (...) needed to answer the sceptical problem satisfactorily. Also, in order to secure a philosophically significant notion of justification and evidence, reasons are given to hold WCJ*, as opposed to rejecting it. This understanding of the sceptical argument would help to focus the real challenge of scepticism. (shrink)

The purpose of this paper is to provide a new solution to the radical sceptical paradox. A sceptical paradox purports to indicate the inconsistency within our fundamental epistemological commitments that are all seemingly plausible. Typically, sceptics employ an intuitively appealing epistemic principle (e.g., the closure principle, the underdetermination principle) to derive the sceptical conclusion. This paper will reveal a dilemma intrinsic to the sceptical paradox, which I refer to as the self-hollowing problem of radical scepticism. That is, on the one (...) hand, if the sceptical conclusion turns out to be true, then the epistemic principle employed by sceptics would lose its foundation of plausibility; on the other hand, if the sceptical conclusion does not follow, then the sceptical problem would not arise. In either case, the so-called sceptical paradox cannot be a genuine paradox. This new solution has three theoretical merits: it is undercutting, less theory-laden, and widely applicable. (shrink)

The first step in responding to the challenge of external world skepticism is to get clear on the structure of the skeptic’s argument. The most prominent varieties of skeptical arguments either rely on closure principles or underdetermination principles. The relationship between these two sorts of arguments is contentious. Some argue that these arguments can independently motivate skepticism. Others argue that they are really equivalent. I argue that although these two arguments are distinct, their independence is not as obvious as some (...) have thought. The fact that these arguments are not equivalent is important because skeptical arguments that appeal to underdetermination principles cannot be refuted by simply denying closure. So, the strategy for responding to skepticism offered by Nozick/Dretske does not seem an adequate solution. (shrink)

A common response to radical skeptical challenges to our knowledge of the external world has been that there are explanatory reasons (e.g., simplicity, coherence, explanatory power, conservatism) for favoring commonsense explanations of our sensory experiences over skeptical explanations. Despite the degree of visibility this class of response has enjoyed, it has often been viewed with skepticism [sic] by the epistemological community because of concerns about the epistemic merits of explanatory reasoning. I argue that skeptical challenges that employ skeptical hypotheses presuppose (...) central explanationist tenets and that this fact should raise one’s estimation of the strength of explanationist responses to skepticism. (shrink)

In this paper a candidate for a rational reconstruction of skeptical arguments is presented and defended against a competitor called ‘The Argument from Ignorance’. On the basis of this defense, Michael Williams’ claims that foundationalism and epistemological realism serve as presuppositions for skepticism are criticized. It is argued that rejecting these two theses, as his version of contextualism does, is not sufficient for answering the skeptical challenge.

Half a century later, a Dretskean stance on epistemic closure remains a minority view. Why? Mainly because critics have successfully poked holes in the epistemologies on which closure fails. However, none of the familiar pro-closure moves works against the counterexamples on display here. It is argued that these counterexamples pose the following dilemma: either accept that epistemic closure principles are false, and steal the thunder from those who attack classical logic on the basis of similarly problematic cases—specifically, relevance logicians and (...) like-minded philosophers—or stick with closure and surrender to relevantist claims of failure in truth-preservation aimed at classical rules of inference. Classicist closure advocates find the promise of a way out of the dilemma in the works of Roy Sorensen and John Hawthorne. The paper argues against their pro-closure move and renews Robert Audi’s call for a theory of closure-failure. (shrink)

The principle of epistemic closure is the claim that what is known to follow from knowledge is known to be true. This intuitively plausible idea is endorsed by a vast majority of knowledge theorists. There are significant problems, however, that have to be addressed if epistemic closure – closed knowledge – is endorsed. The present essay locates the problem for closed knowledge in the separation it imposes between knowledge and evidence. Although it might appear that all that stands between knowing (...) the truth of the premises of a valid inference and knowledge of its conclusion is inferring it from the premises, the evidence for each of the premises may jointly count against the conclusion. The intuitive view regarding inferred knowledge says one thing, the evidence says another. One epistemological framework that seems to have the resources to resolve this tension endorses the view that knowledge always requires conclusive evidence. A second framework resolves the tension by limiting the scope of the closure principle. Only inferences drawn directly from propositions contained in the scope of a single knowledge operator are considered closed. The aim of the present essay is to revive the unpopular third option, the idea that knowledge is open. The essay proceeds by arguing that in different ways the two former frameworks only succeed in relocating the problem, not in resolving it. The first framework, the infallibilist view, relocates the problem to a sharp separation between knowledge of the occurrences of events from knowledge of their chance of occurring, a separation leading to several significant additional problems. The fallibilist view, the second framework, in endorsing closure neglects to take into full account the ways in which evidence fails to be transitive. For instance, evidence can count in favor of a conjunction while counting against each of its conjuncts. This fact, which is argued for in the essay on probabilistic as well as non-probabilistic grounds, is used as the foundation of an argument against closed knowledge that can be used as a way to understand several of the most fundamental challenges of epistemology. Not only can an open knowledge view that is based on open evidence resolve all these problems in a simple and natural way, it can also respond to formidable challenges that significantly hinder other open knowledge views. There are good reasons, then, to view both knowledge and evidence as open. (shrink)

In Radical Skepticism & Epistemic Intuition Michael Bergmann attempts to overcome the threat of radical skepticism as it arises in several different forms. The key to Bergmann’s response to skepticism is his method of intuitionist particularism wherein we give our intuitions about particular beliefs being justified more weight than we do intuitions about the premises of arguments for skepticism. There are two general problems for Bergmann’s response to skepticism. First, he fails to accurately portray the key principle of the skeptical (...) argument. As a result, much of the apparent motivation for looking to intuitionist particularism as opposed to other responses to skepticism is merely apparent. Second, intuitionist particularism faces significant problems when it comes to the Problem of the Criterion and the resolution of conflicting intuitions. However, a related intuitionist method, one incorporating explanationism, may be able to deliver what intuitionist particularism promises while avoiding its problems. (shrink)

The Mundane World Hypothesis (mwh) says that we have material bodies, we have brains located inside our bodies, we have sense organs which process visual information, the direct cause of our perceptual judgments is typically macroscopic material objects, and we live in a material world. Skeptics using underdetermination arguments arguemwhhas no more epistemic merit than some skeptical competitor, e.g., that we are in the Matrix. Since such competitor hypotheses are equipollent, we are not justified in believingmwh. This paper takes the (...) underdetermination skeptic’s premises to a more radical conclusion: skeptical dogmatism, which is the view thatmwhis probably false based on the idea that there are many equipollent competitors tomwh. (shrink)

Radical scepticism contends that our knowledge of the external world is impossible. Particularly, radical scepticism can be motivated by the closure principle. Several commentators have noted that a straightforward way to respond to such arguments is via externalist strategies, e.g., Goldman, Greco, Bergmann. However, these externalist strategies are not effective against a slightly weaker form of the argument, a closure principle for rationally grounded knowledge, closureRK.\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${closure}_{RK.}$$\end{document} The sceptical argument, framed around the (...) closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle, targets rationally grounded knowledge. Although externalist strategies are ineffective against this form of argument, its conclusion can nonetheless be resisted by combining, in a novel way, the resources of Wittgenstein and Davidson. In particular, I argue that the sceptic is assuming an unrestricted way of using the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle, which is incorrect. Alternatively, I argue for The Conditionality of Rational Support Thesis, i.e., the thesis that rational support via competent deduction is conditional. In particular, rational support must be provided within an evaluative system in which hinge propositions are presupposed and contentful beliefs are being evaluated. In the end, we can resist the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK }}$$\end{document}-based sceptical argument while retaining the closureRK\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {closure}_{\mathrm{RK}}$$\end{document} principle. (shrink)

The most prominent arguments for scepticism in modern epistemology employ closure principles of some kind. To begin my discussion of such arguments, consider Simple Knowledge Closure (SKC): (SKC) (Kxt[p] ∧ (p → q)) → Kxt[q].1 Assuming its truth for the time being, the sceptic can use (SKC) to reason from the two assumptions that, firstly, we don’t know ¬sh and that, secondly, op entails ¬sh to the conclusion that we don’t know op, where ‘op’ and ‘sh’ are shorthand for ‘ordinary (...) proposition’ and ‘sceptical hypothesis’ respectively. (SKC), however, fails for familiar reasons: since knowledge entails belief (KB), we can derive the falsity (F) from (SKC) by hypothetical syllogism, and thus reduce (SKC) to absurdity: (KB) Kxt[p] → Bxt[p]. (F) (Kxt[p] ∧ (p → q)) → Bxt[q]. (shrink)

The author argues that is not obvious what it means for our beliefs and assertions to be "truth-directed", and that we need to weaken our ordinary notion of a belief if we are to deal with radical scepticism without surrendering to idealism. Topics examined also include whether there could be alien conceptual schemes and what might happen to us if we abandoned genuine belief in place of mere pragmatic acceptance. A radically new "ecological" model of knowledge is defended.

Based on Pritchard's distinction between favoring and discriminating epistemic grounds, and on how those grounds bear on the elimination of skeptical possibilities, I present the dream argument as a moderate skeptical possibility that can be reasonably motivated. In order to block the dream argument skeptical conclusion, I present a version of phenomenological disjunctivism based on Noë's actionist account of perceptual consciousness. This suggests that perceptual knowledge is rationally grounded because it is a form of embodied achievement - what I call (...) embodied rationality -, which offers a way of dissolving the pseudo-problem of epistemic immodesty, namely, the seemingly counterintuitive thesis that one can acquire rationally grounded knowledge that one is not in a radical skeptical scenario. (shrink)

Contemporary discussions of epistemological skepticism - the view that we do not and cannot know anything about the world around us - focus very much on a certain kind of skeptical argument involving a skeptical scenario (a situation familiar from Descartes’ First Meditation). According to the argument, knowing some ordinary proposition about the world (one we usually take ourselves to know) requires knowing we are not in some such skeptical scenario SK; however, since we cannot know that we are not (...) in SK we also cannot know any ordinary proposition. One of the most prominent skeptical scenarios is the brain-in-the-vat-scenario: An evil scientist has operated on an unsuspecting subject, removed the subject’s brain and put it in a vat where it is kept functioning and is connected to some computer which feeds the brain the illusion that everything is “normal”. This paper looks at one aspect of this scenario after another – envatment, disembodiment, weird cognitive processes, lack of the right kind of epistemic standing, and systematic deception. The conclusion is that none of these aspects (in isolation or in combination) is of any relevance for a would-be skeptical argument; the brain-in-the-vat-scenario is irrelevant to and useless for skeptical purposes. Given that related scenarios (e.g., involving evil demons) share the defects of the brain-in-the-vat-scenario, the skeptic should not put any hopes on Cartesian topoi. (shrink)

Sceptical arguments in epistemology typically employ sceptical hypotheses, which are rivals to our everyday beliefs so constructed that they fit exactly the evidence on which those beliefs are based. There are two ways of using a sceptical hypothesis to undermine an everyday belief, giving rise to two distinct sorts of sceptical argument: underdetermination‐based and closure‐based. However, both sorts of argument, as usually formulated in the literature, fall foul of evidential holism, for they ignore the crucial role of background beliefs. An (...) analogy with the philosophy of science makes this point explicit. There is no simple way to “holism proof” the two sceptical arguments. (shrink)

According to radical scepticism, knowledge of the external world is impossible. Transcendental arguments are supposed to be anti-sceptical, but can they provide a satisfying response to radical scepticism? Especially, when radical scepticism is cast as posing a how-possible question, there is a concern that transcendental arguments are neither sufficient nor necessary for answering such question. In light of this worry, I argue that we can take a modest transcendental argument as a stepping stone for a diagnostic anti-sceptical proposal, and I (...) use a Wittgensteinian modest transcendental argument to illustrate my point. (shrink)