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)

I articulate a functional characterisation of the concept of evidence, according to which evidence is that which allows us to make inferences that extend our knowledge. This entails Williamson's equation of knowledge with evidence.

Belief does aim at the truth. When our beliefs do not fit the facts, they cannot do what they are supposed to do, because they cannot provide us with reasons. We cannot plausibly deny that a truth norm is among the norms that govern belief. What we should not say is that the truth norm is the fundamental epistemic norm. In this paper, I shall argue that knowledge is the norm of belief and that the truth norm has a derivative (...) status. Only a knowledge‐first approach to epistemic normativity can explain why epistemic assessment has its inward‐looking focus. (shrink)

In this paper I outline my conception of the epistemology of science, by reference to my published papers, showing how the ideas presented there fit together. In particular I discuss the aim of science, scientific progress, the nature of scientific evidence, the failings of empiricism, inference to the best (or only) explanation, and Kuhnian psychology of discovery. Throughout, I emphasize the significance of the concept of scientific knowledge.

In this paper, I shall discuss a problem that arises when you try to combine an attractive account of what constitutes evidence with an independently plausible account of the kind of access we have to our evidence. According to E = K, our evidence consists of what we know. According to the principle of armchair access, we can know from the armchair what our evidence is. Combined, these claims entail that we can have armchair knowledge of the external world. Because (...) it seems that the principle of armchair access is supported by widely shared intuitions about epistemic rationality, it seems we ought to embrace an internalist conception of evidence. I shall argue that this response is mistaken. Because externalism about evidence can accommodate the relevant intuitions about epistemic rationality, the principle of armchair access is unmotivated. We also have independent reasons for preferring externalism about evidence to the principle of armchair access. (shrink)

On a standard view about reasons, evidence, and justification, there is justification for you to believe all and only what your evidence supports and the reasons that determine whether there is justification to believe are all just pieces of evidence. This view is mistaken about two things. It is mistaken about the rational role of evidence. It is also mistaken about the rational role of reasons. To show this, I present two basis problems for the standard view and argue that (...) it lacks the resources to solve these problems. It is easy to spot these mistakes once we are clear on the ontology of reasons and have a better understanding of the role that belief plays in the theory of possessed evidence. After attacking the standard view, I offer an alternative account of justification. On this view, the justificatory status of a belief is not a function of the reasons/evidence on which it is based (it might not be based on any) but is instead a function of the basis that it can provide. (shrink)

Consider: -/- The Evidence Question: When, and under what conditions does an agent have proposition E as evidence (at t)? -/- Timothy Williamson's (2000) answer to this question is the well-known E = K thesis: -/- E = K: E is a member of S's evidence set at t iff S knows E at t. -/- I will argue that this answer is inconsistent with the version of Bayesianism that Williamson advocates. This is because E = K allows an agent (...) to garner evidence via inductive inference whereas standard Bayesian views disallow such a thing. Since Williamson's version of Bayesianism shares the key features with the standard Bayesian view, there is an inconsistency. (shrink)

The main question addressed in this paper is whether some false sentences can constitute evidence for the truth of other propositions. In this paper it is argued that there are good reasons to suspect that at least some false propositions can constitute evidence for the truth of certain other contingent propositions. The paper also introduces a novel condition concerning propositions that constitute evidence that explains a ubiquitous evidential practice and it contains a defense of a particular condition concerning the possession (...) of evidence. The core position adopted here then is that false propositions that are approximately true reports of measurements can constitute evidence for the truth of other propositions. So, it will be argued that evidence is only quasi-factive in this very specific sense. (shrink)

A discussion of epistemic reasons, theoretical rationality, and the relationship between them. Discusses the ontology of reasons and evidence, the relationship between reasons (motivating, normative, possessed, apparent, genuine, etc.) and rationality, the relationship between epistemic reasons and evidence, the relationship between rationality, justification, and knowledge, and many other related topics.

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)

Bayesian Epistemology is a general framework for thinking about agents who have beliefs that come in degrees. Theories in this framework give accounts of rational belief and rational belief change, which share two key features: (i) rational belief states are represented with probability functions, and (ii) rational belief change results from the acquisition of evidence. This dissertation focuses specifically on the second feature. I pose the Evidence Question: What is it to have evidence? Before addressing this question we must have (...) an understanding of Bayesian Epistemology. The first chapter argues that we should understand Bayesian Epistemology as giving us theories that are evaluative and not action-guiding. I reach this verdict after considering the popular ‘ought’-implies-‘can’ objection to Bayesian Epistemology. The second chapter argues that it is important for theories in Bayesian Epistemology to answer the Evidence Question, and distinguishes between internalist and externalist answers. The third and fourth chapters present and defend a specific answer to the Evidence Question. The account is inspired by reliabilist accounts of justification, and attempts to understand what it is to have evidence by appealing solely to considerations of reliability. Chapter 3 explains how to understand reliability, and how the account fits with Bayesian Epistemology, in particular, the requirement that an agent’s evidence receive probability 1. Chapter 4 responds to objections, which maintain that the account gives the wrong verdict in a variety of situations including skeptical scenarios, lottery cases, scientific cases, and cases involving inference. After slight modifications, I argue that my account has the resources to answer the objections. The fifth chapter considers the possibility of losing evidence. I show how my account can model these cases. To do so, however, we require a modification to Conditionalization, the orthodox principle governing belief change. I present such a modification. The sixth and seventh chapters propose a new understanding of Dutch Book Arguments, historically important arguments for Bayesian principles. The proposal shows that the Dutch Book Arguments for implausible principles are defective, while the ones for plausible principles are not. The final chapter is a conclusion. (shrink)

We often evaluate belief-forming processes, agents, or entire belief states for reliability. This is normally done with the assumption that beliefs are all-or-nothing. How does such evaluation go when we’re considering beliefs that come in degrees? I consider a natural answer to this question that focuses on the degree of truth-possession had by a set of beliefs. I argue that this natural proposal is inadequate, but for an interesting reason. When we are dealing with all-or-nothing belief, high reliability leads to (...) high levels of truth-possession. However, when it comes to degrees of belief, reliability and truth-possession part ways. The natural answer thus fails to be a good way to evaluate degrees of belief for reliability. I propose and develop an alternative method based on the notion of calibration, suggested by Frank Ramsey, which does not have this problem and consider why we should care about such assessments of reliability even if they are not tied directly to truth-possession. (shrink)

My contribution to the author meets critics discussion of Pritchard's _Epistemological Disjunctivism_. In this paper, I examine some of the possible motivations for epistemological disjunctivism and look at some of the costs associated with the view. While Pritchard's view seems to be that our visual beliefs constitute knowledge because they're based on reasons, I argue that the claim that visual beliefs are based on reasons or evidence hasn't been sufficiently motivated. In the end I suggest that we'll get all the (...) benefits with none of the costs of epistemological disjunctivism if we accept E=K. (shrink)

According to some philosophers who accept a propositional conception of evidence, someone's evidence includes a proposition only if it is true. I argue against this thesis by appealing to the possibility of knowledge from falsehood.

Lewis thought concessive knowledge attributions (e.g., ‘I know that Harry is a zebra, but it might be that he’s just a cleverly disguised mule’) caused serious trouble for fallibilists. As he saw it, CKAs are overt statements of the fallibilist view and they are contradictory. Dougherty and Rysiew have argued that CKAs are pragmatically defective rather than semantically defective. Stanley thinks that their pragmatic response to Lewis fails, but the fallibilist cause is not lost because Lewis was wrong about the (...) commitments of fallibilism. There are problems with Dougherty and Rysiew’s response to Stanley and there are problems with Stanley’s response to Lewis. I’ll offer a defense of fallibilism of my own and show that fallibilists needn’t worry about CKAs. (shrink)

The usual, comparative, conception of inference to the best explanation (IBE) takes it to be ampliative. In this paper I propose a conception of IBE ('Holmesian inference') that takes it to be a species of eliminative induction and hence not ampliative. This avoids several problems for comparative IBE (for example, how could it be reliable enough to generate knowledge?). My account of Holmesian inference raises the suspicion that it could never be applied, on the grounds that scientific hypotheses are inevitably (...) underdetermined by the evidence (i.e. are inevitably ampliative). I argue that this concern may be resisted by acknowledging, as Timothy Williamson has shown, that all knowledge is evidence. The latter suggests an approach to resisting scepticism different from those (e.g. the reliabilist approach) that embrace fallibilism. (shrink)