David Lewis (1941-2001) was Class of 1943 University Professor of Philosophy at Princeton University. His contributions spanned philosophical logic, philosophy of language, philosophy of mind, philosophy of science, metaphysics, and epistemology. In On the Plurality of Worlds, he defended his challenging metaphysical position, "modal realism." He was also the author of the books Convention, Counterfactuals, Parts of Classes, and several volumes of collected papers.

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)

Rational thinkers respect their evidence. Properly understood, that is a platitude. But how can one respect one's evidence unless one knows what it is? So must not rational thinkers know what their evidence is?

What modal relation must a fact bear to a belief in order for this belief to constitute knowledge of that fact? Externalists have proposed various answers, including some that combine externalism with contextualism. We shall find that various forms of externalism share a modal conception of “sensitivity” open to serious objections. Fortunately, the undeniable intuitive attractiveness of this conception can be explained through an easily confused but far preferable notion of “safety.” The denouement of our reflections, finally, will be to (...) show how replacing sensitivity with safety makes it possible to defend plain Moorean common sense against the spurious advantages over it claimed by skeptical, tracking, relevant-alternative, and contextualist accounts. (shrink)

The skeptic says that “knowledge” is an absolute term, whereas the contextualist says that ‘knowledge” is a relationally absolute term. Which is the better hypothesis about “knowledge”? And what implications do these hypotheses about “knowledge” have for knowledge? I argue that the skeptic has the better hypothesis about “knowledge”, but that both hypotheses about “knowledge” have deeply anti‐skeptical implications for knowledge, since both presuppose our capacity for epistemically salient discrimination.

Contextualism treats ‘knows’ as an indexical that denotes different epistemic properties in different contexts. Contrastivism treats ‘knows’ as denoting a ternary relation with a slot for a contrast proposition. I will argue that contrastivism resolves the main philosophical problems of contextualism, by employing a better linguistic model. Contextualist insights are best understood by contrastivist theory.

How should the contrastivist formulate closure? That is, given that knowledge is a ternary contrastive state Kspq (s knows that p rather than q), how does this state extend under entailment? In what follows, I will identify adequacy conditions for closure, criticize the extant invariantist and contextualist closure schemas, and provide a contrastive schema based on the idea of extending answers. I will conclude that only the contrastivist can adequately formulate closure.

A commonly expressed worry in the contemporary literature on the problem of epistemological scepticism is that there is something deeply intellectually unsatisfying about the dominant anti-sceptical theories. In this paper I outline the main approaches to scepticism and argue that they each fail to capture what is essential to the sceptical challenge because they fail to fully understand the role that the problem of epistemic luck plays in that challenge. I further argue that scepticism is best thought of not as (...) a quandary directed at our possession of knowledge simpliciter, but rather as concerned with a specific kind of knowledge that is epistemically desirable. On this view, the source of scepticism lies in a peculiarly epistemic form of angst. It is always by favour of Nature that one knows something. [Wittgenstein 1969: §505]. (shrink)

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)

G. E. Moore famously offered a strikingly straightforward response to the radical sceptic which simply consisted of the claim that one could know, on the basis of one's knowledge that one has hands, that there exists an external world. In general, the Moorean response to scepticism maintains that we can know the denials of sceptical hypotheses on the basis of our knowledge of everyday propositions. In the recent literature two proposals have been put forward to try to accommodate, to varying (...) extents, this Moorean thesis. On the one hand, there are those who endorse an externalist version of contextualism, such as Keith DeRose, who have claimed that there must be some contexts in which Moore is right. More radically still, Ernest Sosa has expanded on this externalist thesis by arguing that, contra DeRose's contextualism, Moore may be right in all contexts. In this paper I evaluate these claims and argue that, suitably modified, one can resurrect the main elements of the Moorean anti-sceptical thesis. (shrink)

Attributer contextualism has undoubtedly been the dominant anti-sceptical theory in the recent literature. Nevertheless, this view does face some fairly serious problems, and it is argued that when the contextualist position is compared to a refined version of the much derided 'Moorean' response to scepticism, then it becomes clear that there are distinct advantages to being a neo-Moorean rather than a contextualist.

At the very least, externalists about content will accept something like the following claim.

A great deal of discussion in the recent literature has been devoted to the so-called 'McKinsey' paradox which purports to show that semantic externalism is incompatible with the sort of authoritative knowledge that we take ourselves to have of our own thought contents. In this paper I examine one influential epistemological response to this paradox which is due to Crispin Wright and Martin Davies. I argue that it fails to meet the challenge posed by McKinsey but that, if it is (...) set within an externalist epistemology, it may have application to a related paradox that concerns the problem of radical scepticism. (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)

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)

Rieber 1998 proposes an account of "S knows that p" that generates a contextualist solution to Closure. In this paper, I’ll argue that Rieber’s account of "S knows that p" is subject to fatal objections, but we can modify it to achieve an adequate account of "S knows that p" that generates a unified contextualist solution to all four puzzles. This is a feat that should matter to those philosophers who have proposed contextualist solutions to Closure: all of them have (...) motivated their contextualism by appeal to the fact that they can explain the plausibility of each of the statements in Closure taken individually, and they can do this without having to deny that each of those statements is true, at least in the context in which it is plausible. But notice that this consideration would equally well motivate a contextualist approach to the other puzzles. Nonetheless, no contextualist has yet suggested how a contextualist solution to the other puzzles might go. (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)

We describe the three place relation of contrastive knowledge, which holds between a person, a target proposition, and a contrasting proposition. The person knows that p rather than that q. We argue for three claims about this relation. (a) Many common sense and philosophical ascriptions of knowledge can be understood in terms of it. (b) Its application is subject to fewer complications than non-contrastive knowledge is. (c) It applies over a wide range of human and nonhuman cases.

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)

Nozick analyzes fundamental issues, such as the identity of the self, knowledge and skepticism, free will, the foundations of ethics, and the meaning of life.

This anthology brings together ten papers which have defined and advanced the debate between internalism and externalism in epistemology.

This discussion surveys recent developments in the treatment of the epistemological problem of skepticism. These are arguments which attack our knowledge of certain truths rather than, say, our belief in the existence of certain entities. In particular, this article focuses on the radical versions of these skeptical arguments, arguments which purport to show that knowledge is, for the most part, impossible, rather than just that we lack knowledge in a particular discourse. Although most of the key recent developments in this (...) area have taken place since the late 1980s and early 1990s, it is necessary to also discuss some of the movements that have developed since 1970 in order to give these recent developments the necessary setting. The date of 1970 is dictated by the publication in that year of Fred Dretske’s seminal article “Epistemic Operators,” which both pushed a “relevant alternatives” theory of knowledge to the fore of discussion and also brought into focus one possible line of argument against the so-called “closure” principle for knowledge. In so doing, it provided one of the main sources of response to the emergent.. (shrink)