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)

This book takes purism about knowledge as the default position and defends it from the challenges of pragmatic encroachment. The book is divided into two parts, a negative and a positive one. The negative part critically examines existing purist strategies in response to pragmatic encroachment. The positive part provides a new theory of how practical factors can systematically influence our confidence and explores some implications of such influence.

At the core of evidentialism lies a very plausible claim: rational thinkers follow their evidence. While this seems to be a very intuitive, almost trivial, claim, providing a full and complete evidentialist theory is complicated. In this entry, I begin with elucidating what kind of theory evidentialists aim to provide us with. I will show that, in order to provide a complete evidentialist theory, we have to provide a lot of details on what evidence is and how it relates to (...) the proposition it’s evidence for, as well as the agent possessing such evidence. I then consider objections arising for the most popular answers one can give to such questions. I conclude by considering old and new challenges that arise for evidentialism, regardless of the specific version one endorses. (shrink)

There is a large literature exploring how accuracy constrains rational degrees of belief. This paper turns to the unexplored question of how accuracy constrains knowledge. We begin by introducing a simple hypothesis: increases in the accuracy of an agent’s evidence never lead to decreases in what the agent knows. We explore various precise formulations of this principle, consider arguments in its favour, and explain how it interacts with different conceptions of evidence and accuracy. As we show, the principle has some (...) noteworthy consequences for the wider theory of knowledge. First, it implies that an agent cannot be justified in believing a set of mutually inconsistent claims. Second, it implies the existence of a kind of epistemic blindspot: it is not possible to know that one’s evidence is misleading. (shrink)

Considerations of scientific evidence are often thought to provide externalism with the dialectical upper hand in the internalism–externalism debate. How so? A couple of reasons are forthcoming in the literature. (1) Williamson (2000) argues that the E = K thesis (in contrast to internalism) provides the best explanation for the fact that scientists appear to argue from premises about true propositions (or facts) that are common knowledge among the members of the scientific community. (2) Kelly (Philosophy Compass, 3 (5), 933–955, (...) 2008; 2016) argues that only externalism is suited to account for the public character of scientific evidence. In this article, I respond to Williamson and Kelly’s arguments. First, I show that the E = K thesis isn’t supported by the way in which we talk about scientific evidence, and that it is unable to account for facts about what has been regarded as scientific evidence and as justified scientific belief in the history of science. Second, I argue that there are internalist views that can account for the publicity of scientific evidence, and that those views indeed do better in that regard than the (externalist) view proposed by Kelly. The upshot is that considerations of scientific evidence do not favor externalism over internalism. (shrink)

Wordly internalists claim that while internal duplicates always share the same evidence, our evidence includes non-trivial propositions about our environment. It follows that some evidence is false. Worldly internalism is thought to provide a more satisfying answer to scepticism than classical internalist views that deny that these propositions about our environment might belong to our evidence and to provide a generally more attractive account of rationality and reasons for belief. We argue that worldly internalism faces serious difficulties and that its (...) apparent advantages are illusory. First, it cannot adequately handle some not terribly strange cases of perceptual error. Second, it cannot explain why one should plan to use their evidence to update their beliefs. The second issue allows us to explain why cases of misplaced certainty do not require us to introduce false evidence into our views and that why the alleged advantage of worldly internalism in resisting sceptical pressures is illusory. (shrink)

If updating with E has the same result across all epistemically possible worlds, then the agent has no uncertainty as to the behavior of the update, and we may call it a transparent update. If an agent is uncertain about the behavior of an update, we may call it opaque. In order to model the uncertainty an agent has about the result of an update, the same update must behave differently across different possible worlds. In this paper, I study opaque (...) updates using a simple system of dynamic epistemic logic suitably modified for that purpose. The paper highlights the connection between opaque updates and the dynamic-epistemic principles Perfect-Recall and No-Miracles. I argue that opaque updates are central to contemporary discussions in epistemology, in particular to externalist theories of knowledge and to the related problem of epistemic bootstrapping, or easy knowledge. Opaque updates allow us to explicitly investigate a dynamic form of uncertainty, using simple and precise logical tools. (shrink)

First aim of this paper is to show that Evidentialism, when paired with a Psychologistic ontology of evidence, is unable to account for ordinary cases of inferential justification. As many epistemologists have maintained, however, when it is paired with a Propositionalist ontology of evidence, Evidentialism is unable to explain in a satisfactory way ordinary cases of perceptual justification. So, the Evidentialist is faced with a dilemma. Second aim of this paper is to give an argument in favour of Propositionalism about (...) evidence, and so to motivate the conclusion that perceptual justification must be accounted for in non-evidentialist terms. By this I do not mean to defend a strongly Non-Evidentialist epistemology, according to which there are doxastic attitudes which are unsupported by any justifier. More modestly, I aim to motivate the weakly Non-Evidentialist epistemology according to which a subject’s perceptual beliefs may be justified by non-evidential justifiers. I conclude the paper by explaining why I believe that Pryor's dogmatism supplies a model for the way in which an internalist who is persuaded by my argument might want to detail her weakly Non-Evidentialist account of perceptual justification. (shrink)

There are many important dimensions of epistemic evaluation, one of which is justification. We don’t just evaluate beliefs for truth, reliability, accuracy, and knowledge, but also for justification. However, in the epistemological literature, there is much disagreement about the nature of justification and how it should be understood. One of the controversies that has separated the contemporary epistemological discourse into two opposing camps has to do with the internalism-externalism distinction. Whereas internalists defend certain core assumptions about justification from the pre-Gettier (...) tradition, externalists generally think that the traditional conception is untenable and should be replaced. In this compilation thesis, I argue for, defend, and develop a particular brand of internalism, both in general and with respect to specific sources of justification. In papers 1 and 2, I defend a couple of well-known arguments for mentalism and accessibilism. Moreover, I also point out how prominent versions of these theses are vulnerable to serious problems (e.g., about over-intellectualization and vicious regresses). Part of my goal in the first couple of papers is to figure out what commitments the internalist should take on in order to avoid the externalist's objections, while at the same time receiving support from considerations that have motivated internalism in the past. In papers 3 and 4, I start from the assumption that mentalism is true and attempt to answer the following questions: 1) which non-factive mental states can play a justification-conferring role with respect to empirical belief? And 2) why does this set of states play the epistemic role it does? In response to question 1, I argue that all and only one's beliefs and perceptual experiences have justificatory relevance. In response to question 2, I argue that one's beliefs and perceptual experiences are one's strongly representational states, and that strongly representational states necessarily provide support to certain empirical propositions. Having done so, I then defend mentalism about scientific evidence from a couple of prominent objections in the recent literature. Lastly, in papers 5 and 6, I argue for a particular brand of internalism about testimonial and memorial justification and show how that position has a dialectical advantage over its main competitors. (shrink)

In recent years, some defenders of traditional philosophical methodology have argued that certain critiques of armchair methods are mistaken in assuming that intuitions play central evidential roles in traditional philosophical methods. According to this kind of response, experimental philosophers attack a straw man; it doesn’t matter whether intuitions are reliable, because philosophers don’t use intuitions in the way assumed. Deutsch (2010), Williamson (2007), and Cappelen (2012) all defend traditional methods in something like this way. I also endorsed something like this (...) line in Ichikawa (2014a). -/- In this contribution, I will follow up on this sort of defence of traditional philosophical methods in three ways. In §1, I will rehearse and extend some of my reasons for challenging the idea that traditional methods depend on intuitions in an evidential role. (My reasons are very different from those discussed in (Cappelen, 2012).) I will also engage with some recent more sophisticated attempts to establish the idea that intuitions play evidential roles in philosophy, such as that of Chudnoff (2013). In §2, I will consider and argue against a dismissive response to such positions from experimental philosophers, who consider the question of philosophical reliance on intuitions to be irrelevant to the experimentalist critique. But in §3, I will argue that it would also be a mistake to conclude (as Herman Cappelen does) that the critique is rendered totally irrelevant by the denial of the evidential role of intuitions; I defend a more moderate view on which the bearing of experimental studies of philosophical intuitions is relevant for philosophical methodology, but only in a relatively limited way. (shrink)

In this article I focus on some unduly neglected common-sense considerations supporting the view that one's evidence is the propositions that one knows. I reply to two recent objections to these considerations.

Greaves and Wallace argue that conditionalization maximizes expected accuracy. In this paper I show that their result only applies to a restricted range of cases. I then show that the update procedure that maximizes expected accuracy in general is one in which, upon learning P, we conditionalize, not on P, but on the proposition that we learned P. After proving this result, I provide further generalizations and show that much of the accuracy-first epistemology program is committed to KK-like iteration principles (...) and to the existence of a class of propositions that rational agents will be certain of if and only if they are true. (shrink)

A growing number of authors defend putative examples of knowledge from falsehood (KFF), inferential knowledge based in a critical or essential way on false premises, and they argue that KFF has important implications for many areas of epistemology (whether evidence can be false, the Gettier debate, defeasibility theories of knowledge, etc.). I argue, however, that there is no KFF, because in any supposed example either the falsehood does not contribute to the knowledge or the subject lacks knowledge. In particular, I (...) show that if the subject actually has knowledge in putative KFF cases, then there is always a veridical evidential path meeting the basing conditions that accounts for her knowledge; if there is no such path, then the subject is in a type of Gettier case. All the recent arguments that rely on KFF are therefore based on a mistake. (shrink)

In this paper, first, I distinguish four questions concerning evidence: (a) the ontological question: what kind of entity qualifies as evidence? (b) the possession question: what is it for S to possess evidence? (c) the evidential relation question: what is it for one or a set of things to be evidence for another? And (d) the evidential basis question: how does S’s evidence contribute to forming, maintaining, or revising S’s doxastic attitudes? Williamson’s E = K thesis is only concerned with (...) question (b). Next, I argue that three recent arguments against the E = K thesis miss the target either because they combine the E = K thesis with something alien, or because they conflate these questions. The arguments I address are the argument from access to evidence, the argument from evidential bootstrapping, and the argument from true belief based on falsehood. The argument from access to evidence combines the E = K thesis with a quasi-skeptical consideration. The argument from evidential bootstrapping is only directed at Williamson’s theory of probability, which is his answer to question (c). The argument from true belief based on falsehood derives its force from an assumption about the basing relation as an answer to question (d). Although I do not deny that it is possible to argue for or against the E = K thesis by appealing to answers to other questions than (b), it is no easy task. (shrink)

Our beliefs utilize various sources: perception, memory, induction, etc. We trust these sources to provide reliable information about the world around us. My dissertation investigates how this trust could be justified. Chapter one introduces background material. I argue that justification rather than knowledge is of primary epistemological importance, discuss the internalism/externalism debate, and introduce an evidentialist thesis that provides a starting point/framework for epistemological theorizing. Chapter two introduces a puzzle concerning justification. Can a belief source provide justification absent prior justification (...) for believing it's reliable? Any answer appears to either make justifying the reliability of a source intellectually unsatisfying or all together impossible. Chapter three considers and rejects a plethora of proposed solutions to our puzzle. Investigating these solutions illustrates the need to further investigate evidence, evidence possession, and evidential support. Chapter four discusses the metaphysics of evidence. I argue that evidence always consists of a set of facts and that fact-proposition pairs stand in confirmation relations isomorphic to those holding between pairs of propositions. Chapter five argues that justification requires what I call actually connected possession of supporting evidence: a subject must be aware of supporting evidence and of the support relation itself. Chapter six argues that the relation constitutive of a set of facts being justificatory evidence is a sui generis and irreducible relation that is knowable a priori. Chapter seven begins by showing how Richard Fumerton's acquaintance theory meets the constraints on a theory of justification laid down in previous chapters. I modify the theory so as to: make room for fallible foundational justification, and allow inferential justification absent higher-order beliefs about evidential connections. Chapter eight applies the developed theory of justification to our initial puzzle. I show how my modified acquaintance theory is in a unique position to vindicate the idea that necessarily a source provides a person with justification only if she is aware of evidence for the reliability of that source. However, this awareness of evidence for a source's reliability falls short of a justified belief and thereby avoids impalement from our dilemma's skeptical horn. (shrink)

If evidence is propositional, is one’s evidence limited to true propositions or might false propositions constitute evidence? In this paper, I consider three recent attempts to show that there can be ‘false evidence,’ and argue that each of these attempts fails. The evidence for the thesis that evidence consists of truths is much stronger than the evidence offered in support of the theoretical assumptions that people have relied on to argue against this thesis. While I shall not defend the view (...) that evidence is propositional, I shall defend the view that any propositional evidence must be true. (shrink)

***Revisitando o Conhecimento a partir de Falsidade***Os defensores da teoria do Conhecimento a partir de Falsidade nos apresentam exemplos putativos de conhecimento inferencial nos quais um sujeito S, supostamente, adquire conhecimento através de uma inferência competente realizada a partir de uma falsidade. Se eles estiverem certos, teremos que enfrentar alguns problemas importantes para a epistemologia do raciocínio. No entanto, neste artigo, argumentarei que não há conhecimento a partir de falsidades, os casos apresentados pelos defensores de KFF não constituem casos de (...) conhecimento inferencial genuíno e a reação intuitiva de atribuir conhecimento ao sujeito em tais casos não tem nenhuma relação com a falsidade. Eu irei direcionar a minha oposição à KFF através de duas objeções que ofereço à explicação apresentada por Peter Klein em seu artigo "Useful False Beliefs". Em particular, mostro que a explicação de Klein falha porque ela é incapaz de demonstrar como uma falsidade pode fornecer um status epistêmico positivo à crença inferida para torná-la conhecimento; e ela é incompatível com uma noção tácita e amplamente aceita de inferência. (shrink)

According to the knowledge view of evidence notoriously defended by Timothy Williamson (2000), for any subject, her evidence consists of all and only her propositional knowledge (E=K). Many have found (E=K) implausible. However, few have offered arguments against Williamson’s positive case for (E=K). In this paper, I propose an argument against Williamson’s positive case in favour of (E=K). Central to my argument is the possibility of the knowledge of necessary truths. I also draw some more general conclusions concerning theorizing about (...) evidence. (shrink)

What can we learn from cases of knowledge from falsehood? Critics of knowledge-first epistemology have argued that these cases provide us with good reason for rejecting the knowledge accounts of evidence, justification, and the norm of belief. I shall offer a limited defense of the knowledge-first approach to these matters. Knowledge from falsehood cases should undermine our confidence in like-from-like reasoning in epistemology. Just as we should be open to the idea that knowledge can come from non-knowledge, we should be (...) open to the idea that justified beliefs can come from unjustified beliefs. (shrink)

Evidentialism is an internalist view (or family of views) about epistemic justification saying that a subject s’s epistemic justification entirely depends on the evidence at her disposal. In order to distil a complete theory of epistemic justification from this general principle it is necessary to answer three main questions. What kind of entities constitute a subject’s evidence? What does it take for a piece of evidence E to support a proposition P? What does it take for a subject s to (...) possess E? In this entry I describe the main answers defended in the literature in response to these three questions, and critically discuss the main objections that have been raised against evidentialism, both at a general level and as targeting more specific variants of it. (shrink)

Two of the most influential arguments for Bayesian updating ("Conditionalization") -- Hilary Greaves' and David Wallace's Accuracy Argument and David Lewis' Diachronic Dutch Book Argument-- turn out to impose a strong and surprising limitation on rational uncertainty: that one can never be rationally uncertain of what one's evidence is. Many philosophers ("externalists") reject that claim, and now seem to face a difficult choice: either to endorse the arguments and give up Externalism, or to reject the arguments and lose some of (...) the best justifications of Bayesianism. The author argues that the key to resolving this conflict lies in recognizing that both arguments are plan-based, in that they argue for Conditionalization by first arguing that one should planto conditionalize. With this in view, we can identify the culprit common to both arguments: for an externalist, they misconceive the requirement to carry out a plan made at an earlier time. They should therefore not persuade us to reject Externalism. Furthermore, rethinking the nature of this requirement allows us to give two new arguments for Conditionalization that do not rule out rational uncertainty about one's evidence and that can thus serve as common ground in the debate between externalists and their opponents. (shrink)