Claudio de Almeida

Faced with vivid cases of inferential knowledge to which false premises seem evidentially indispensable—knowledge-from-falsehood cases, or 'KFF cases'—some of us retreat from the traditional, Aristotelian view that only knowledge begets knowledge in reasoning. But KFF-ers are a minority in the debate over such cases. The epistemology of reasoning is still dominated by KDF-ers, those for whom, on close inspection, purported KFF cases turn out to be knowledge-despite-falsehood cases. Each group has its own warring factions. I belong with those who think that every KDF proposal on the market is hopeless, which saddles me with the fundamental problem for KFF-ers: the task of explaining why some false premises are knowledge-suppressing, or 'malignant', while others are knowledge-yielding, or 'benign'. Some have suggested that a satisfactory KFF view might be found within truth-tracking epistemologies, either a safety-based theory or a sensitivity-based one. I examine the hypothesis and conclude that it fails. I then turn to the defeasibility theory of knowledge, a theory that has been deployed by its chief architect, Peter Klein, in defense of a KDF stance, and argue that the desired benign/malignant distinction can be found within a properly formulated, non-Kleinian defeasibility theory.

Contrary to millennial thought, inferential knowledge does seem to arise in certain cases of reasoning to which false premises are evidentially essential. The phenomenon refutes all of the well-known epistemologies that account for inferential knowledge. I offer an explanation of the phenomenon based on a fairly conservative revision to the defeasibility theory of knowledge, and explain why Peter Klein’s proposed solution fails. The explanation put forward here aims at giving us these two highly desirable results: (a) something we have never had and may not have noticed we needed, a defeasibility theory that is compatible with epistemological fallibilism, and, (b) within this revised, fallibilistic version of the defeasibility theory, an explanation of the benign/malignant distinction for false beliefs that completes the defeasibilist resolution of the Gettier Problem.

On the basis of arguments showing that none of the most influential analyses of Moore's paradox yields a successful resolution of the problem, a new analysis of it is offered. It is argued that, in attempting to render verdicts of either inconsistency or self‐contradiction or self‐refutation, those analyses have all failed to satisfactorily explain why a Moore‐paradoxical proposition is such that it cannot be rationally believed. According to the proposed solution put forward here, a Moore‐paradoxical proposition is one for which the believer can have no non‐overridden evidence. the arguments for this claim make use of some of Peter Klein's views on epistemic defeasibility. It is further suggested that this proposal may have important meta‐epistemological implications.

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.

Moore′s paradox came of age when John N. Williams gave us a simple paradoxical argument according to which the Moorean believer must hold false belief while believing contingent propositions. Simplicity was key; it was groundbreaking for the topic. On Williams′s account, given only the notions of inconsistency and self‐refutation, the thesis that belief distributes over conjunction, and a tiny bit of classical logic, we can derive a paradox from the Moorean propositional schemata. But, as argued here, it′s easy to overestimate the significance of his argument to a proper understanding of the problem. His fundamental claim can be established in a way that shows how the paradox arises for any propositional attitude that distributes over conjunction, which gives us the opportunity to reconsider the problem we have been calling “Moore′s paradox”, and to conclude that all of the available analyses of the problem are, at best, incomplete. On this new approach, we lose a little formal simplicity vis‐à‐vis Williams′s approach, but make conceptual economy, as we gain a farther‐reaching problem than the one we have known.

The aim of the thesis is twofold. Firstly, it is argued that Frege's theory of meaning and denotation is the first successful non-psychologistic response to what has been called 'the puzzle of identity' and that, where Frege's theory differs most significantly from the theory of meaning and denotation developed by Russell in The Principles of Mathematics and in his unpublished manuscripts on logic of 1903-1905, Russell was right. Secondly, it is shown that Russell was again right when he claimed that the central argument of 'On Denoting' completely discredits both his own and Frege's theory of meaning and denotation. An interpretation of the relevant passage of 'On Denoting' is put forward. The discussion makes evident that it is virtually impossible to disentangle that argument if one ignores his unpublished work on the topic.

On the basis of arguments showing that none of the most influential analyses of Moore’s paradox yields a successful resolution of the problem, a new analysis of it is offered. It is argued that, in attempting to render verdicts of either inconsistency or self-contradiction or self-refutation, those analyses have all failed to satisfactorily explain why a Moore-paradoxical proposition is such that it cannot be rationally believed. According to the proposed solution put forward here, a Moore-paradoxical proposition is one for which the believer can have no non-overridden evidence. The arguments for this claim make use of some of Peter Klein’s views on epistemic defeasibility. It is further suggested that this proposal may have important meta-epistemological implications.

G. E. Moore identified a peculiar form of epistemic irrationality. Wittgenstein called it “Moore’s Paradox”. Neither of them knew exactly what he was talking about. And yet, the vast literature on the problem leaves no room for doubt: the paradox is deep; its resolution, elusive. But, up until now, we haven’t been in a position to appreciate its importance for contemporary epistemology. This paper puts forward an epistemological solution to the paradox. It also seeks to show that the paradox yields counter-examples to deductive closure claims for both epistemic rationality and knowledge that are immune to contextualist pro-closure maneuvers.

Talk of ‘defeasible/nondefeasible reasoning’ by some of our leading epistemologists and logicians is misleading. It embodies conceptual confusion about epistemic defeasibility, fallibility, and monotonicity in influential accounts of inferential justification. As argued here, this form of deeply entrenched confusion has blurred the distinction between the concepts of fallibility and defeasibility under the guise of the seemingly benign synonymy between the labels ‘defeasible reasoning’ and ‘nonmonotonic reasoning.’ The careless employment of these labels has had a harmful effect on our understanding of inferential justification. Specifically, it has blurred the fundamental distinction between truth-preservation and justification-preservation in the relevant literature, thus harming the epistemology of reasoning at its core. We have been warned by Timothy Williamson against this kind of confusion, but the warning has gone unheeded. That warning is explained and amplified here on the basis of abundant textual evidence and the discussion of exemplary cases.

The effort to understand Peter D. Klein’s work on (so-called) Cartesian skepticism is simply not optional to anyone wishing to become familiar with state-of-the-art scholarship on the problem. Nearly four decades ago, Klein developed the invariantist pro-closure response to Fred Dretske’s counterexamples to epistemic closure principles, thus stealing some of the thunder from the nascent, Dretske-inspired contextualist views in epistemology. Since then, he’s added important theoretical elements to his analysis of the central problem of our debate about skepticism and closure: the problem of how a closure defender might refute the Cartesian skeptic without turning into a purveyor of ‘easy knowledge.’ According to Klein, “a proper understanding of closure shows that the [Cartesian] skeptic cannot provide a good argument for her view and helps to show that there is no genuine problem of easy knowledge” (see “Closure Matters: Academic Skepticism and Easy Knowledge” 2004). Indeed, inattention to Klein’s work accounts for some of the most important fallacies perpetrated in the recent literature on epistemic principles that may be of use to the skeptic. Still, on close inspection, Klein’s case against Cartesian skepticism proves optimistic. The chapter briefly reviews the main features of 34 years of Klein’s work on the problem in 15 publications, from his 1981 book on Certainty to his 2015 Stanford Encyclopedia of Philosophy entry “Skepticism”. It finds that his case against the skeptic is a distinctive mixture of Mooreanism and Russellianism and concludes that none of his main objections to Cartesian skepticism is tenable.

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.