According to the safety account of knowledge, one knows that p only if one's belief could not easily have been false. An important issue for the account is whether we should only examine the belief in the target proposition when evaluating whether a belief is safe or not. In this paper, it is argued that if we only examine the belief in the target proposition, then the account fails to account for why beliefs in necessary truths could fall short of (...) knowledge. But, if we also examine beliefs in other relevant propositions, then the account fails to preserve epistemic closure. Therefore, the safety account cannot find a safe path between epistemic closure and necessary truths. (shrink)

Ted A. Warfield reviews the history of epistemology and argues that epistemologists mistakenly take for granted the inference that the failure of closure of some necessary condition on knowledge is sufficient for the failure of epistemic closure. So he concludes that epistemologists should avoid using this inference to explain the failure of epistemic closure. However, I will defend the inference that epistemologists often employ in their discussions. My thesis is that although this inference is invalid, one can still legitimately conclude (...) the failure of epistemic closure from the failure of closure of some necessary condition on knowledge. (shrink)

I set out the standard view about alleged examples of failure of transmission of warrant, respond to two cases for the view, and argue that the view is false. The first argument for the view neglects the distinction between believing a proposition on the basis of a justification and merely having a justification to believe a proposition. The second argument for the view neglects the position that one's justification for believing a conclusion can be one's premise for the conclusion, rather (...) than simply one's justification for the premise. Finally, the view is false since it is inconsistent with the closure of knowledge as closure is properly understood. (shrink)

The paper argues that knowledge is not closed under logical inference. The argument proceeds from the openness of evidential support and the dependence of empirical knowledge on evidence, to the conclusion that knowledge is open. Without attempting to provide a full-fledged theory of evidence, we show that on the modest assumption that evidence cannot support both a proposition and its negation, or, alternatively, that information that reduces the probability of a proposition cannot constitute evidence for its truth, the relation of (...) evidential support is not closed under known entailment. Therefore the evidence-for relation is deductively open regardless of whether evidence is probabilistic or not. Given even a weak dependence of empirical knowledge on evidence, we argue that empirical knowledge is also open. On this basis, we also respond to the strongest argument in support of knowledge closure. Finally, we present a number of significant benefits of our position, namely, offering a unified explanation for a range of epistemological puzzles. (shrink)

This paper looks at an argument strategy for assessing the epistemic closure principle. This is the principle that says knowledge is closed under known entailment; or (roughly) if S knows p and S knows that p entails q, then S knows that q. The strategy in question looks to the individual conditions on knowledge to see if they are closed. According to one conjecture, if all the individual conditions are closed, then so too is knowledge. I give a deductive argument (...) for this conjecture. According to a second conjecture, if one (or more) condition is not closed, then neither is knowledge. I give an inductive argument for this conjecture. In sum, I defend the strategy by defending the claim that knowledge is closed if, and only if, all the conditions on knowledge are closed. After making my case, I look at what this means for the debate over whether knowledge is closed. (shrink)

Consider the following proposition: It is possible that all of our perceptual experiences are ‘delusive.’ According to Gilbert Ryle, is demonstrably absurd. In this paper I address four questions: What is Ryle’s argument against?; How persuasive is it?; What positions are ruled out if is absurd?; and How does Ryle’s position compare with contemporary work on skepticism?

John Hawthorne has two forceful arguments in favour of:Single-Premise Closure Necessarily, if S knows p, competently deduces q from p, and thereby comes to believe q, while retaining knowledge of p throughout, then S knows q.Each of Hawthorne's arguments rests on an intuitively appealing principle which Hawthorne calls the Equivalence Principle. I show, however, that the opponents of SPC with whom he's engaging - namely Fred Dretske and Robert Nozick - have independent reason to reject this principle, and resultantly conclude (...) that Hawthorne's arguments in favour of SPC are not knock-down. (shrink)

Transmission arguments against closure of knowledge base the case against closure on the premise that a necessary condition for knowledge is not closed. Warfield argues that this kind of argument is fallacious whereas Brueckner, Murphy and Yan try to rescue it. According to them, the transmission argument is no longer fallacious once an implicit assumption is made explicit. I defend Warfield’s objection by arguing that the various proposals for the unstated assumption either do not avoid the fallacy or turn the (...) central premise of the transmission argument, namely that a necessary condition is not closed, into a redundant and superfluous premise. I conclude that Warfield’s advice is still to be heeded: Arguments against closure must not rely essentially on the premise that a necessary condition for knowledge is not closed. (shrink)

Reliabilists accept the possibility of basic knowledge—knowledge that p in virtue of the reliability of some belief-producing process r without antecedent knowledge that r is reliable. Cohen (Philos Phenomenol Res 65:309–329, 2002 , Philos Phenomenol Res 70:417–430, 2005 ) and Vogel (J Philos 97:602–623, 2000 , J Philos 105:518–539, 2008 ) have argued that one can bootstrap knowledge that r is reliable from basic knowledge. This paper provides a diagnosis of epistemic bootstrapping, and then shows that recent attempts at embracing (...) bootstrapped knowledge are found wanting. Instead it is argued that such arguments are afflicted by a novel kind of generalized epistemic circularity. The ensuing view is defended against various objections, and an explanation of the source of that circularity is offered. (shrink)

Epistemic closure has been a central issue in epistemology over the last forty years. According to versions of the relevant alternatives and subjunctivist theories of knowledge, epistemic closure can fail: an agent who knows some propositions can fail to know a logical consequence of those propositions, even if the agent explicitly believes the consequence (having “competently deduced” it from the known propositions). In this sense, the claim that epistemic closure can fail must be distinguished from the fact that agents do (...) not always believe, let alone know, the consequences of what they know—a fact that raises the “problem of logical omniscience” that has been central in epistemic logic. This paper, part I of II, is a study of epistemic closure from the perspective of epistemic logic. First, I introduce models for epistemic logic, based on Lewis’s models for counterfactuals, that correspond closely to the pictures of the relevant alternatives and subjunctivist theories of knowledge in epistemology. Second, I give an exact characterization of the closure properties of knowledge according to these theories, as formalized. Finally, I consider the relation between closure and higher-order knowledge. The philosophical repercussions of these results and results from part II, which prompt a reassessment of the issue of closure in epistemology, are discussed further in companion papers. As a contribution to modal logic, this paper demonstrates an alternative approach to proving modal completeness theorems, without the standard canonical model construction. By “modal decomposition” I obtain completeness and other results for two non-normal modal logics with respect to new semantics. One of these logics, dubbed the logic of ranked relevant alternatives, appears not to have been previously identified in the modal logic literature. More broadly, the paper presents epistemology as a rich area for logical study. (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.

Some incompatibilists about free will or moral responsibility and determinism would abandon their incompatibilism were they to learn that determinism is true. But is it reasonable to flip-flop in this way? In this article, we contend that it is and show what follows. The result is both a defense of a particular incompatibilist strategy and a general framework for assessing other cases of flip-flopping.

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)

Tracking theories of knowledge are widely known to have the consequence that knowledge is not closed. Recent arguments by Vogel and Hawthorne claim both that there are no legitimate examples of knowledge without closure and that the costs of theories that deny closure are too great. This paper considers the tracking theories of Dretske and Nozick and the arguments by Vogel and Hawthorne. We reject the arguments of Vogel and Hawthorne and evaluate the costs of closure denial for tracking theories (...) of knowledge. (shrink)