I discuss three ways of responding to the logical omniscience problems faced by traditional ‘possible worlds’ epistemic logics. Two of these responses were put forward by Hintikka and the third by Cresswell; all three have been influential in the literature on epistemic logic. I show that both of Hintikka's responses fail and present some problems for Cresswell’s. Although Cresswell's approach can be amended to avoid certain unpalatable consequences, the resulting formal framework collapses to a sentential model of knowledge, which defenders (...) of the ‘possible worlds’ approach are frequently critical of. (shrink)

Knowledge and its Limits presents a systematic new conception of knowledge as a kind of mental stage sensitive to the knower's environment. It makes a major contribution to the debate between externalist and internalist philosophies of mind, and breaks radically with the epistemological tradition of analyzing knowledge in terms of true belief. The theory casts new light on such philosophical problems as scepticism, evidence, probability and assertion, realism and anti-realism, and the limits of what can be known. The arguments are (...) illustrated by rigorous models based on epistemic logic and probability theory. The result is a new way of doing epistemology and a notable contribution to the philosophy of mind. (shrink)

In this paper, I explain the curious role played by the Argument from Absolute Terms in Peter Unger's book Ignorance, I provide a critical presentation of the argument, and I consider some outstanding issues and the argument’s contemporary significance.

Attributer contextualists maintain that the verb 'knows' is context-sensitive in the sense that the truth conditions of a sentence of the form "S knows that p" can be dependent upon the ascriber's context. One natural objection against attributer contextualism is that it confuses the impropriety of certain assertions which ascribe knowledge to agents with the falsity of those assertions. In an influential article, Keith DeRose has defended attributer contextualism against this charge by proposing constraints on what he calls "warranted assertibility (...) manoeuvres" of this sort. This paper argues that, contra DeRose, the warranted assertibility manoeuvre directed at attributer contextualism is able to meet the constraints that DeRose lays down. (shrink)

Unbelievable Errors defends an error theory about all normative judgements: not just moral judgements, but also judgements about reasons for action, judgements about reasons for belief, and instrumental normative judgements. This theory states that normative judgements are beliefs that ascribe normative properties, but that normative properties do not exist. It therefore entails that all normative judgements are false. -/- Bart Streumer also argues, however, that we cannot believe this error theory. This may seem to be a problem for the theory. (...) But he argues that it makes this error theory more likely to be true, since it undermines objections to the theory and it makes it harder to reject the arguments for the theory. -/- He then sketches how certain other philosophical theories can be defended in a similar way. He concludes that to make philosophical progress, we need to make a sharp distinction between a theory's truth and our ability to believe it. (shrink)

This completely self-contained study, widely considered the best book in the field, is intended to serve both as an introduction to quantification theory and as ...

Arguments strong enough to justify skeptical theism will be strong enough to justify the position that every claim about God is empirically unfalsifiable. This fact is problematic because that position licenses further arguments which are clearly unreasonable, but which the skeptical theist cannot consistently accept as such. Avoiding this result while still achieving the theoretical objectives looked for in skeptical theism appears to demand an impossibly nuanced position.

In this short but meaty book, Peter Unger questions the objective answers that have been given to central problems in philosophy. As Unger hypothesizes, many of these problems are unanswerable, including the problems of knowledge and scepticism, the problems of free will, and problems of causation and explanation. In each case, he argues, we arrive at one answer only relative to an assumption about the meaning of key terms, terms like "know" and like "cause," even while we arrive at an (...) opposite answer relative to quite different assumptions, but equally arbitrary assumptions, about what the key terms mean. (shrink)

In this essay I show how to reconcile epistemic invariantism with the knowledge account of assertion. My basic proposal is that we can comfortably combine invariantism with the knowledge account of assertion by endorsing contextualism about speech acts. My demonstration takes place against the backdrop of recent contextualist attempts to usurp the knowledge account of assertion, most notably Keith DeRose's influential argument that the knowledge account of assertion spells doom for invariantism and enables contextualism's ascendancy.

Duncan Pritchard has argued that luck is fundamentally a modal notion: an event is lucky when it occurs in the actual world, but does not occur in more than half of the relevant nearby possible worlds. Jennifer Lackey has provided counterexamples to accounts which, like Pritchard’s, only allow for the existence of improbable lucky events. Neil Levy has responded to Lackey by offering a modal account of luck which attempts to respect the intuition that some lucky events occur in more (...) than half of the relevant nearby possible worlds. But his account rejects that events which are as likely as those in Lackey’s examples are lucky. Instead, they are merely fortunate. I argue that Levy’s argument to this effect fails. I then offer a substitute account of the improbability condition which respects this intuition. This condition says that the relevant notion of probability for luck is epistemic. (shrink)

Strict moderate invariantism is the ho-hum, ‘obvious’ view about knowledge attributions. It says knowledge attributions are often true and that only traditional epistemic factors like belief, truth, and justification make them true. As commonsensical as strict moderate invariantism is, it is equally natural to withdraw a knowledge attribution when error possibilities are made salient. If strict moderate invariantism is true, these knowledge-denials are often false because the subject does in fact know the proposition. I argue that strict moderate invariantism needs (...) an explanation of this phenomenon, but it does not have one. That is significant, for if strict moderate invariantism does not square with ordinary intuition, then it cannot rely on ordinary intuition for support. Section 1 introduces the concept of epistemic relevance blindness, which says ordinary subjects are generally insensitive to whether or not error possibilities are relevant to knowledge attributions. Section 2 focuses on Patrick Rysiew’s influential strict moderate invariantist pragmatic explanation of knowledge-denials and argues that such pragmatic explanations of knowledge-denials depend on attributors being epistemic relevance blind. Section 3 targets psychological explanations of epistemic relevance blindness offered separately by Jennifer Nagel and Mikkel Gerken. I argue that strict moderate invariantists lack a plausible explanation of epistemic relevance blindness. (shrink)

This paper is a companion piece to my earlier paper “Fallibilism and Concessive Knowledge Attributions”. There are two intuitive charges against fallibilism. One is that it countenances the truth (and presumably acceptability) of utterances of sentences such as “I know that Bush is a Republican, though it might be that he is not a Republican”. The second is that it countenances the truth (and presumably acceptability) of utterances of sentences such as “I know that Bush is a Republican, even though (...) I’m not certain that he is”, or “I know that Bush it a Republican, even though it isn’t certain that he is.” In “Fallibilism and Concessive Knowledge Attributions”, I argue that fallibilism in epistemology does not countenance the truth of utterances of sentences such as “I know that Bush is a Republican, though it might be that he is not a Republican”. In this paper, I argue that there are independent reasons for thinking that utterances of sentences such as “I know that Bush is a Republican, though I’m not certain that he is” and “I know that Bush is a Republican, though it’s not certain that he is” are unassertible. More specifically, I argue that these are simply instances of Moore’s Paradox, such as “Dogs bark, but I don’t know that they do.” The right account of Moore’s Paradox does not involve the falsehood of the semantic content of the relevant utterances, but rather their pragmatic unacceptability. So the anti-fallibilist intuitions turn out to have pragmatic, rather than semantic import, and therefore do not tell against the truth of fallibilism. Fallibilism in epistemology is often thought to be theoretically desirable, but intuitively problematic. My purpose with these two papers is to show that fallibilism is not intuitively problematic. (shrink)

Jason Stanley presents a startling and provocative claim about knowledge: that whether or not someone knows a proposition at a given time is in part determined by his or her practical interests, i.e. by how much is at stake for that person at that time. In defending this thesis, Stanley introduces readers to a number of strategies for resolving philosophical paradox, making the book essential not just for specialists in epistemology but for all philosophers interested in philosophical methodology. Since a (...) number of his strategies appeal to linguistic evidence, it will be of great interest to linguists as well. (shrink)

Lewis concludes that fallibilism is uncomfortable, though preferable to scepticism. However, he believes that contextualism about knowledge allows us to ‘dodge the choice’ between fallibilism and scepticism. For the contextualist semantics for ‘know’ can explain the oddity of fallibilism, without landing us into scepticism.

This account of the conflict between phrenologists and anti-phrenologists in early nineteenth-century Edinburgh is offered as a case study in the sociological explanation of intellectual activity. The historiographical value and propriety of a sociological approach to ideas is defended against accounts which assume the autonomy of knowledge. By attending to the social context of the debate and the functions of ideas in that context one may construct an explanation of why the conflict took the course it did.

The idea that knowledge can be extended by inference from what is known seems highly plausible. Yet, as shown by familiar preface paradox and lottery-type cases, the possibility of aggregating uncertainty casts doubt on its tenability. We show that these considerations go much further than previously recognized and significantly restrict the kinds of closure ordinary theories of knowledge can endorse. Meeting the challenge of uncertainty aggregation requires either the restriction of knowledge-extending inferences to single premises, or eliminating epistemic uncertainty in (...) known premises. The first strategy, while effective, retains little of the original idea—conclusions even of modus ponens inferences from known premises are not always known. We then look at the second strategy, inspecting the most elaborate and promising attempt to secure the epistemic role of basic inferences, namely Timothy Williamson’s safety theory of knowledge. We argue that while it indeed has the merit of allowing basic inferences such as modus ponens to extend knowledge, Williamson’s theory faces formidable difficulties. These difficulties, moreover, arise from the very feature responsible for its virtue- the infallibilism of knowledge. (shrink)

Stephen Schiffer; XIII*—Contextualist Solutions to Scepticism, Proceedings of the Aristotelian Society, Volume 96, Issue 1, 1 June 1996, Pages 317–334, https://.

Almost every contemporary theory of knowledge is a version of fallibilism, yet an adequate statement of fallibilism has not yet been provided. Standard definitions cannot account for fallibilistic knowledge of necessary truths. I consider and reject several attempts to resolve this difficulty before arguing that a belief is an instance of fallibilistic knowledge when it could have failed to be knowledge. This is a fully general account of fallibilism that applies to knowledge of necessary truths. Moreover, it reveals, not only (...) the connection between fallibility and error, but the connection between fallibility and accidental truth as well. (shrink)

Hilary Putnam deals in this book with some of the most fundamental persistent problems in philosophy: the nature of truth, knowledge and rationality. His aim is to break down the fixed categories of thought which have always appeared to define and constrain the permissible solutions to these problems.

The recent popularity of contextualist treatments of the key epistemic concepts has tended to obscure the differences that exist between the various kinds of contextualist theses on offer. The aim of this paper is to contribute towards rectifying this problem by exploring two of the main formulations of the contextualist position currently on offer in the literature—the 'semantic' contextualist thesis put forward by Keith DeRose and David Lewis, and the 'inferential' contextualist thesis advanced by Michael Williams. It is argued that (...) by evaluating these theses in the light of each other one can gain a deeper understanding of the contextualist position. In particular, it is argued that this relative evaluation highlights one interesting way in which contextualism might be developed. (shrink)

One of the key supposed 'platitudes' of contemporary epistemology is the claim that knowledge excludes luck. One can see the attraction of such a claim, in that knowledge is something that one can take credit for - it is an achievement of sorts - and yet luck undermines genuine achievement. The problem, however, is that luck seems to be an all-pervasive feature of our epistemic enterprises, which tempts us to think that either scepticism is true and that we don't know (...) very much, or else that luck is compatible with knowledge after all. In this book, Duncan Pritchard argues that we do not need to choose between these two austere alternatives, since a closer examination of what is involved in the notion of epistemic luck reveals varieties of luck that are compatible with knowledge possession and varieties that aren't. Moreover, Pritchard shows that a more nuanced understanding of the relationship between luck and knowledge can cast light on many of the most central topics in contemporary epistemology. These topics include: the externalism/internalism distinction; virtue epistemology; the problem of scepticism; metaepistemological scepticism; modal epistemology; and the problem of moral luck. All epistemologists will need to come to terms with Pritchard's original and incisive contribution. (shrink)

In this book Pollock deals with the subject of probabilistic reasoning, making general philosophical sense of objective probabilities and exploring their ...

There was a long tradition in philosophy according to which good reasoning had to be deductively valid. However, that tradition began to be questioned in the 1960’s, and is now thoroughly discredited. What caused its downfall was the recognition that many familiar kinds of reasoning are not deductively valid, but clearly confer justification on their conclusions. Here are some simple examples.

According to Williamson, your evidence consists of all and only what you know (E = K). According to his critics, it doesn’t. While E = K calls for revision, the revisions it calls for are minor. E = K gets this much right. Only true propositions can constitute evidence and anything you know non-inferentially is part of your evidence. In this paper, I defend these two theses about evidence and its possession from Williamson’s critics who think we should break more (...) radically from E = K. (shrink)

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.

The evidential argument from evil seeks to show that suffering is strong evidence against theism. The core idea of the evidential argument is that we know of innocent beings suffering for no apparent good reason. Perhaps the most common criticism of the evidential argument comes from the camp of skeptical theism, whose lot includes William Alston, Alvin Plantinga, and Stephen Wykstra. According to skeptical theism the limits of human knowledge concerning the realm of goods, evils, and the connections between values, (...) undermines the judgment that what appears as pointless evil really is pointless. For all we know the suffering of an innocent being, though appearing pointless, in fact leads to a greater good. In this paper I argue that no one who accepts the doctrines of skeptical theism has a principled way of avoiding moral skepticism. (shrink)

This article defends the view that knowledge is type-identical to cognitive achievement. I argue, pace Duncan Pritchard, that not only knowledge, but also cognitive achievement is incompatible with environmental luck. I show that the performance of cognitive abilities in environmental luck cases does not distinguish them from non-abilities per se. For this reason, although the cognitive abilities of the subject are exercised in environmental luck cases, they are not manifested in any relevant sense. I conclude by showing that this explanation (...) is not ad hoc as it can be generalized to apply to causal features besides cognitive abilities. (shrink)

This paper evaluates a number of closure principles (for both knowledge and justification) that have appeared in the literature. Counterexamples are presented to all but one of these principles, which is conceded to be true but trivially so. It is argued that a consequence of the failure of these closure principles is that certain projects of doxastic logic are doomed, and that doxastic logic is of dubious merit for epistemologists interested in actual knowers in the actual world.