Certainty The following article provides an overview of the philosophical debate surrounding certainty. It does so in light of distinctions that can be drawn between objective, psychological, and epistemic certainty. Certainty consists of a valuable cognitive standing, which is often seen as an ideal. It is indeed natural to evaluate lesser cognitive standings, in particular … Continue reading Certainty →.

A-theorists and B-theorists debate whether the "Now" is metaphysically distinguished from other time slices. Analogously, one may ask whether the "I" is metaphysically distinguished from other perspectives. Few philosophers would answer the second question in the affirmative. An exception is Caspar Hare, who has devoted two papers and a book to arguing for such a positive answer. In this paper, I argue that those who answer the first question in the affirmative---A-theorists---should also answer the second question in the affirmative. This (...) is because key arguments in favor of the A-theory are more effective asarguments in favor of the resulting combined position, and key arguments against the A-theory are ineffective against the combined position. (shrink)

Formal models of appearance and reality have proved fruitful for investigating structural properties of perceptual knowledge. This paper applies the same approach to epistemic justification. Our central goal is to give a simple account of The Preface, in which justified belief fails to agglomerate. Following recent work by a number of authors, we understand knowledge in terms of normality. An agent knows p iff p is true throughout all relevant normal worlds. To model The Preface, we appeal to the normality (...) of error. Sometimes, it is more normal for reality and appearance to diverge than to match. We show that this simple idea has dramatic consequences for the theory of knowledge and justification. Among other things, we argue that a proper treatment of The Preface requires a departure from the internalist idea that epistemic justification supervenes on the appearances and the widespread idea that one knows most when free from error. (shrink)

Fallibilists claim that one can know a proposition on the basis of evidence that supports it even if the evidence doesn't guarantee its truth. Jessica Brown offers a compelling defence of this view against infallibilists, who claim that it is contradictory to claim to know and yet to admit the possibility of error.

Justification as Ignorance offers an original account of epistemic justification as both non-factive and luminous, vindicating core internalist intuitions without construing justification as an internal condition knowable by reflection alone. Sven Rosenkranz conceives of justification, in its doxastic and propositional varieties, as a kind of epistemic possibility of knowing and of being in a position to know. His account contrasts with recent alternative views that characterize justification in terms of the metaphysical possibility of knowing. Instead, he develops a suitable non-normal (...) multi-modal epistemic logic for knowledge and being in a position to know that respects the finding that these notions create hyperintensional contexts. He also defends his conception of justification against well-known anti-luminosity arguments, shows that the account allows for fruitful applications and principled solutions to the lottery and preface paradoxes, and provides a metaphysics of justification and its varying degrees of strength that is compatible with core assumptions of the knowledge-first approach and disjunctivist conceptions of mental states. (shrink)

Epistemic modal operators give rise to something very like, but also very unlike, Moore's paradox. I set out the puzzling phenomena, explain why a standard relational semantics for these operators cannot handle them, and recommend an alternative semantics. A pragmatics appropriate to the semantics is developed and interactions between the semantics, the pragmatics, and the definition of consequence are investigated. The semantics is then extended to probability operators. Some problems and prospects for probabilistic representations of content and context are explored.

Many epistemologists call themselves ‘fallibilists’. But many philosophers of language hold that the meaning of epistemic usages of ‘possible’ ensures a close knowledge- possibility link : a subject’s utterance of ‘it’s possible that not-p’ is true only if the subject does not know that p. This seems to suggest that whatever the core insight behind fallibilism is, it can’t be that a subject could have knowledge which is, for them, possibly false. I argue that, on the contrary, subjects can have (...) such possibly false knowledge. My ultimate aim, then, is to vindicate a very robust form of fallibilism. Uniquely, however, the account I offer does this while also allowing that concessive knowledge attributions – sentences of the form “I know that p, but it’s possible that not-p” – are not only infelicitous but actually false whenever uttered. The account predicts this result without conceding KPL. I argue that my account has the resources to explain some related cases for which the KPL account yields the wrong predictions. Taken as a whole, the linguistic data not only do not support the proposal that subjects cannot have possibly false knowledge, but indeed positively favor the proposal that they can. (shrink)

It is widely held that assertions are partially governed by an epistemic norm. But what is the epistemic condition set out in the norm? Is it knowledge, truth, belief, or something else? In this paper, I defend a view similar to that of Stanley (2008), according to which the relevant epistemic condition is epistemic certainty, where epistemic certainty (but not knowledge) is context-sensitive. I start by distinguishing epistemic certainty, subjective certainty, and knowledge. Then, I explain why it's much more plausible (...) to think that "certain", rather than "know", is context-sensitive. After that, I respond to an important worry raised by Pritchard, according to which the proposed view is too strong to accommodate our current practice of assertion. I then show that the main linguistic and conversational data advanced in the recent literature in favour of the knowledge condition are best explained by the certainty view. Finally, I offer two principled considerations: the certainty view is the only one compatible with three independently plausible claims and it fits very well with the common thought that knowledge does not entail certainty. (shrink)

The aim of this paper is twofold: (i) to introduce the framework of update semantics and to explain what kind of semantic phenomena may successfully be analysed in it: (ii) to give a detailed analysis of one such phenomenon: default reasoning.

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.

According to the widely endorsed Knowledge Account of Assertion, the epistemic requirements on assertion are captured by the Knowledge Norm of Assertion, which requires speakers only to assert what they know. This paper proposes that in addition to the Knowledge Norm there is also an Epistemic Propositional Certainty Norm of Assertion, which enjoins speakers only to assert p if they believe that p on the basis of evidence which makes p an epistemic propositional certainty. The paper explains how this propositional (...) certainty norm accounts for a range of data related to the practice of assertion and defends the norm against general objections to certainty norms of assertion put forward by Duncan Pritchard, John Turri, and Timothy Williamson, by drawing on linguistic theories about epistemic modals and gradable predicate semantics. Together these considerations show that the prospects of a certainty account of assertion are much more promising than is usually assumed. (shrink)

Alex Worsnip argues in favor of what he describes as a particularly robust version of fallibilism: subjects can sometimes know things that are, for them, possibly false (in the epistemic sense of 'possible'). My aim in this paper is to show that Worsnip’s argument is inconclusive for a surprising reason: the existence of possibly false knowledge turns on how we ought to model entailment or consequence relations among sentences in natural language. Since it is an open question how we ought (...) to think about consequence in natural language, it is an open question whether there is possibly false knowledge. I close with some reflections on the relation between possibly false knowledge and fallibilism. I argue that there is no straightforward way to use linguistic data about natural language epistemic modals to either verify or refute the fallibilist thesis. (shrink)

Seven proposed accounts of epistemic possibility are criticized, and a new account is proposed, making use of the notion of having justification for dismissing a proposition. The new account explains intuitions about otherwise puzzling cases, upholds plausible general principles about epistemic possibility, and explains the practical import of epistemic modality judgements. It is suggested that judgements about epistemic possibility function to assess which propositions are worthy of further inquiry.

Introduction -- Fallibilism -- Contextualism -- Knowledge and reasons -- Justification -- Belief -- The value and importance of knowledge -- Infallibilism or pragmatic encroachment? -- Appendix I: Conflicts with bayesian decision theory? -- Appendix II: Does KJ entail infallibilism?

If knowing requires believing on the basis of evidence that entails what’s believed, we have hardly any knowledge at all. Hence the near-universal acceptance of fallibilism in epistemology: if it's true that "we are all fallibilists now" (Siegel 1997: 164), that's because denying that one can know on the basis of non-entailing evidence1is, it seems, not an option if we're to preserve the very strong appearance that we do know many things (Cohen 1988: 91). Hence the significance of concessive knowledge (...) attributions (CKAs) (Rysiew 2001)—i.e., sentences of the form 'S knows that p, but it's possible that q' (where q entails not-p). To many, utterances of such sentences sound very odd indeed. According to David Lewis (1996: 550), however, such sentences are merely "overt, explicit" statements of fallibilism; if so, their seeming incoherence suggests that, contrary to our everyday epistemic pretensions, "knowledge must be by definition infallible" after all (ibid.: 549). -/- Recently Jason Stanley (2005) has defended fallibilism against the Lewisian worry that overtly fallibilistic speech is incoherent. According yo Stanley, CKAs are not just odd-sounding: in most cases, they are simply false. But this doesn't impugn fallibilism. Insofar as the odd-sounding utterances Lewis cites state the fallibilist idea, the latter portion thereof ('S cannot eliminate a certain possibility in which not-p', e.g.) expresses the idea that the subject's evidence doesn't entail what's (allegedly) known (hence, the negation of any contrary propositions). According to Stanley, however, this is not the best reading of the possibility clauses CKAs contain. On the correct account of the latter, while the sentences Lewis cites are almost always self-contradictory, they don't capture the fallibilist idea after all. Here, we argue that the sentences in question do express precisely the fallibilist idea, but argue that Lewis has nonetheless failed to raise a problem for the latter. In addition, we respond to worries that the resulting view of the semantics of epistemic possibility statements has certain unacceptable consequences. (shrink)

Recently, Dylan Dodd (this Journal ) has tried to clear up what he takes to be some of the many confusions surrounding concessive knowledge attributions (CKAs)—i.e., utterances of the form “S knows that p , but it’s possible that q ” (where q entails not- p ) (Rysiew, Noûs 35(4): 477–514, 2001). Here, we respond to the criticisms Dodd offers of the account of the semantics and the sometime-infelicity of CKAs we have given (Dougherty and Rysiew, Philosophy and Phenomenological Research (...) 78(1): 121–132, 2009), showing both how Dodd misunderstands certain central features of that view and how the latter can, pace Dodd, be naturally extended to explain the oddity of those “For all I know” statements to which Dodd draws attention. (shrink)

Concessive knowledge attributions (CKAs) are knowledge attributions of the form ‘S knows p, but it’s possible that q’, where q obviously entails not-p (Rysiew, Nous (Detroit, Mich.) 35:477–514, 2001). The significance of CKAs has been widely discussed recently. It’s agreed by all that CKAs are infelicitous, at least typically. But the agreement ends there. Different writers have invoked them in their defenses of all sorts of philosophical theses; to name just a few: contextualism, invariantism, fallibilism, infallibilism, and that the knowledge (...) rules for assertion and practical reasoning are false. In fact, there is a lot of confusion about CKAs and their significance. I try to clear some of this confusion up, as well as show what their significance is with respect to the debate between fallibilists and infallibilists about knowledge in particular. (shrink)

The apparent contextual variability exhibited by ‘knows’ and its cognates—brought to attention in examples like Keith DeRose’s Bank Case—poses familiar problems for conservative forms of invariantism about ‘knows’. The paper examines and criticises a popular response to those problems, one that involves appeal to so-called ‘pragmatic’ features of language. It is first argued, contrary to what seems to have been generally assumed, that any pragmatic defence faces serious problems with regard to our judgments about retraction. Second, the familiar objection that (...) the pragmatic effects at issue do not seem to be cancellable is considered. Advocates of the pragmatic defence have suggested that cancellability concerns can be dealt with fairly readily. It is shown both that their recent attempts to respond to those concerns, and some other possible attempts, are unsuccessful. Finally, it is argued that the popular relevance-based accounts, found in the work of Jessica Brown, Alan Hazlett, and Patrick Rysiew, fail to provide a satisfactory explanation of our judgments. (shrink)

This paper argues that we should assign certainty a central place in epistemology. While epistemic certainty played an important role in the history of epistemology, recent epistemology has tended to dismiss certainty as an unattainable ideal, focusing its attention on knowledge instead. I argue that this is a mistake. Attending to certainty attributions in the wild suggests that much of our everyday knowledge qualifies, in appropriate contexts, as certain. After developing a semantics for certainty ascriptions, I put certainty to explanatory (...) work. Specifically, I argue that by taking certainty as our central epistemic notion, we can shed light on a variety of important topics, including evidence and evidential probability, epistemic modals, and the normative constraints on credence and assertion. (shrink)