This paper argues for a sufficient evidence condition on knowledge and I argue that there is no belief condition on knowledge.

Higher‐order evidence can make an agent doubt the reliability of her reasoning. When this happens, it seems rational for the agent to adopt a cautious attitude towards her original conclusion, even in cases where the higher‐order evidence is misleading and the agent's original reasons were actually perfectly good. One may think that recoiling to a cautious attitude in the face of misleading self‐doubt involves a failure to properly respond to one's reasons. My aim is to show that this is not (...) so. My proposal is that (misleading) higher‐order evidence can undermine the agent's possession of her first‐order reasons, constituting what I call a dispossessing defeater. After acquiring the higher‐order evidence, the agent is no longer in a position to rely competently on the relevant first‐order considerations as reasons for her original conclusion, so that such reasons stop being available to her (even if they remain as strong as in the absence of the higher‐order evidence). In this way, an agent with misleading higher‐order evidence can adopt a cautious stance towards her original conclusion, while properly responding to the set of reasons that she possesses–a set that is reduced due to the acquisition of higher‐order dispossessing defeaters. (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.

One widely-endorsed argument in the experimental philosophy literature maintains that intuitive judgments are unreliable because they are influenced by the order in which thought experiments prompting those judgments are presented. Here, we explicitly state this argument from ordering effects and show that any plausible understanding of the argument leads to an untenable conclusion. First, we show that the normative principle is ambiguous. On one reading of the principle, the empirical observation is well-supported, but the normative principle is false. On the (...) other reading, the empirical observation has only weak support, and the normative principle, if correct, would impugn the reliability of deliberative reasoning, testimony, memory, and perception, since judgments in all these areas are sensitive to ordering in the relevant sense. We then reflect on what goes wrong with the argument. (shrink)

This paper defends and develops the capacity view against insightful critiques from Matt McGrath, Adam Pautz, and Ram Neta. In response to Matt McGrath, I show why capacities are essential and cannot simply be replaced with representational content. I argue moreover, that the asymmetry between the employment of perceptual capacities in the good and the bad case is sufficient to account for the epistemic force of perceptual states yielded by the employment of such capacities. In response to Adam Pautz, I (...) show why a perceiver’s belief is better justified than the belief of someone who suffers a subjectively indistinguishable hallucination. I show, moreover, why the capacity view is compatible with standard Bayesian principles and how it accounts for degrees of justification. In response to Ram Neta, I discuss the relationship between evidence and rational confidence, as well as the notion of evidence in light of an externalism about perceptual content. (shrink)

Perceptions guide our actions and provide us with evidence of the world around us. Illusions and hallucinations can mislead us: they may prompt as to act in ways that do not mesh with the world around us and they may lead us to form false beliefs about that world. The capacity view provides an account of evidence that does justice to these two facts. It shows in virtue of what illusions and hallucinations mislead us and prompt us to act. Moreover, (...) it shows in virtue of what we are in a better epistemic position when we perceive than when we hallucination. In this paper, I develop the capacity view, that is, the view that perceptual experience has epistemic force in virtue of the epistemic and metaphysical primacy of the perceptual capacities employed in perception. By grounding the epistemic force of experience in facts about the metaphysical structure of experience, the capacity view is not only an externalist view, but moreover a naturalistic view of the epistemology of perceptual experience. So it is an externalist and naturalistic alternative to reliabilism. I discuss the repercussions of this view for the justification of beliefs and the epistemic transparency of mental states, as well as, familiar problem cases. (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)

Williamson (2000) appeals to considerations about when it is natural to say that a hypothesis is consistent with one’s evidence in order to motivate the claim that all and only knowledge is evidence. It is argued here that the relevant considerations do not support this claim, and in fact conflict with it.

What is the metaphysical nature of perceptual experience? What evidence does experience provide us with? These questions are typically addressed in isolation. In order to make progress in answering both questions, perceptual experience needs to be studied in an integrated manner. I develop a unified account of the phenomenological and epistemological role of perceptual experience, by arguing that sensory states provide perceptual evidence due to their metaphysical structure. More specifically, I argue that sensory states are individuated by the perceptual capacities (...) employed and that there is an asymmetric dependence between their employment in perception and their employment in hallucination and illusion. Due to this asymmetric dependence, sensory states provide us with evidence. (shrink)

I describe two traditions of philosophical accounts of evidence: one characterizes the notion in terms of signs of success, the other characterizes the notion in terms of conditions of success. The best examples of the former rely on the probability calculus, and have the virtues of generality and theoretical simplicity. The best examples of the latter describe the features of evidence which scientists appeal to in practice, which include general features of methods, such as quality and relevance, and general features (...) of evidence, such as patterns in data, concordance with other evidence, and believability of the evidence. Two infamous episodes from biomedical research help to illustrate these features. Philosophical characterization of these latter features—conditions of success—has the virtue of potential relevance to, and descriptive accuracy of, practices of experimental scientists. (shrink)

The concept of evidence is among the central concerns of epistemology broadly construed. As such, it has long engaged the intellectual energies of both philosophers of science and epistemologists of a more traditional variety. Here I briefly survey some of the more important ideas to have emerged from this tradition of reflection. I then look somewhat more closely at an issue that has recently come to the fore, largely as a result of Williamson's Knowledge and Its Limits: that of whether (...) one's evidence supervenes on one's non-factive mental states. (shrink)

Defined narrowly, epistemology is the study of knowledge and justified belief. As the study of knowledge, epistemology is concerned with the following questions: What are the necessary and sufficient conditions of knowledge? What are its sources? What is its structure, and what are its limits? As the study of justified belief, epistemology aims to answer questions such as: How we are to understand the concept of justification? What makes justified beliefs justified? Is justification internal or external to one's own mind? (...) Understood more broadly, epistemology is about issues having to do with the creation and dissemination of knowledge in particular areas of inquiry. This article will provide a systematic overview of the problems that the questions above raise and focus in some depth on issues relating to the structure and the limits of knowledge and justification. (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)

This paper explores what happens if we construe evidentialism as a thesis about the metaphysical grounds of justification. According to grounding evidentialism, facts about what a subject is justified in believing are grounded in facts about that subject’s evidence. At first blush, grounding evidentialism appears to enjoy advantages over a more traditional construal of evidentialism as a piece of conceptual analysis. However, appearances are deceiving. I argue that grounding evidentialists are unable to provide a satisfactory story about what grounds the (...) evidential facts, and that this provides good reason to reject grounding evidentialism. (shrink)

An influential proposal is that knowledge involves safe belief. A belief is safe, in the relevant sense, just in case it is true in nearby metaphysically possible worlds. In this paper, I introduce a distinct but complementary notion of safety, understood in terms of epistemically possible worlds. The main aim, in doing so, is to add to the epistemologist’s tool-kit. To demonstrate the usefulness of the tool, I use it to advance and assess substantive proposals concerning knowledge and justification.

Forty years ago, Bayesian philosophers were just catching a new wave of technical innovation, ushering in an era of scoring rules, imprecise credences, and infinitesimal probabilities. Meanwhile, down the hall, Gettier’s 1963 paper [28] was shaping a literature with little obvious interest in the formal programs of Reichenbach, Hempel, and Carnap, or their successors like Jeffrey, Levi, Skyrms, van Fraassen, and Lewis. And how Bayesians might accommodate the discourses of full belief and knowledge was but a glimmer in the eye (...) of Isaac Levi. Forty years later, scoring rules, imprecise credences, and infinitesimal probabilities are all the rage. And the formal and “informal” traditions are increasingly coming together as Bayesian arguments spill over into debates about the foundations of empirical knowledge, skepticism, and more. Relatedly, Bayesian interest in full belief and knowledge has never been greater. Much more besides has happened in the last forty years of Bayesian philosophy, .. (shrink)

In updating our beliefs on the basis of our background attitudes and evidence we frequently employ objects in our environment to represent pertinent information. For example, we may write our premises and lemmas on a whiteboard to aid in a proof or move the beads of an abacus to assist in a calculation. In both cases, we generate extramental (that is, occurring outside of the mind) representational states, and, at least in the case of the abacus, we operate over these (...) states in light of their contents (e.g., the integers represented by the beads) to generate new representations. In this paper, I argue that our belief updating processes and the grounds of their rational evaluation are partly constituted by extramental representations and operations. In other words, we don’t merely update our attitudes through an internal process of reasoning on the basis of available evidence. If we are to accurately understand and rationally evaluate our belief updating processes and resultant attitudes, we need to examine how we representationally appropriate our extramental environment in the updating process. (shrink)

According to a doctrine that I call “Cartesianism”, knowledge – at least the sort of knowledge that inquirers possess – requires having a reason for belief that is reflectively accessible as such. I show that Cartesianism, in conjunction with some plausible and widely accepted principles, entails the negation of a popular version of Fallibilism. I then defend the resulting Cartesian Infallibilist position against popular objections. My conclusion is that if Cartesianism is true, then Descartes was right about this much: for (...) S to know that p, S must have reasons for believing that p which are such that S can know, by reflection alone, that she has those reasons, and that she could not possibly have those reasons if p is not true. Where Descartes went wrong was in thinking that our ordinary, fallible, non-theologically grounded sources of belief (e.g., perception, memory, testimony), cannot provide us with such reasons. (shrink)

My topic in this paper is a particular species of epistemic justification – a species that, following Roderick Firth, I call “propositional justification.”1 Propositional justification is a relation between a person and a proposition. I will say that for S to bear the propositional justification relation to p is for S to be “justified in believing” that p. What is propositional justification? What is it for S to be justified in believing that p? Here’s my answer.

What sorts of things can be evidence for belief? Five answers have been defended in the recent literature on the ontology of evidence: propositions, facts, psychological states, factive psychological states, all of the above. Each of the first three views privileges a single role that the evidence plays in our doxastic lives, at the cost of occluding other important roles. The fifth view, pluralism, is a natural response to such dubious favouritism. If we want to be monists about evidence and (...) accommodate all roles for the concept, we need to think of evidence as propositional, psychological and factive. Our only present option along these lines is the fourth view, which holds that evidence consists of all and only known propositions. But the view comes with some fairly radical commitments. This paper proposes a more modest view—‘truthy psychologism’. According to this view, evidence is also propositional, psychological and factive; but we don’t need the stronger claim that only knowledge can fill this role; true beliefs are enough. I first argue for truthy psychologism by appeal to some standard metaethical considerations. I then show that the view can accommodate all of the roles epistemologists have envisaged for the concept of evidence. Truthy psychologism thus gives us everything we want from the evidence, without forcing us to go either pluralist or radical. (shrink)

Framing systematics as a field consistent with scientific inquiry entails that inferences of phylogenetic hypotheses have the goal of producing accounts of past causal events that explain differentially shared characters among organisms. Linking observations of characters to inferences occurs by way of why-questions implied by data matrices. Because of their form, why-questions require the use of common-cause theories. Such theories in phylogenetic inferences include natural selection and genetic drift. Selection or drift can explain ‘morphological’ characters but selection cannot be causally (...) applied to sequences since fitness differences cannot be directly associated with individual nucleotides or amino acids. The relation of selection to sequence data is by way of downward or top-down causation from those phenotypes upon which selection occurs. The application of phylogenetic inference to explain sequence data is thus restricted to instances where drift is the relevant theory; those nucleotides or amino acids that can be explained via downward causation are precluded from inclusion in the data matrix. The restrictions on the inclusion of sequence data in phylogenetic inferences equally apply to species hypotheses, precluding the more restrictive approach known as DNA barcoding. Not being able to discern drift and selection as relevant causal mechanisms can severely constrain the inclusion and explanations of sequence data. Implications of such exclusion are discussed in relation to the requirement of total evidence. (shrink)

Consider the Evidence Question: When and under what conditions is proposition P evidence for some agent S? Silins (Philos Perspect 19:375–404, 2005) has recently offered a partial answer to the Evidence Question. In particular, Silins argues for Evidential Internalism (EI), which holds that necessarily, if A and B are internal twins, then A and B have the same evidence. In this paper I consider Silins’s argument, and offer two response on behalf of Evidential Externalism (EE), which is the denial of (...) Evidential Internalism. The first response claims that the allegedly unattractive consequence for EE is not so unattractive. The second response takes the form of a tu quoque, demonstrating that a structurally similar argument can be constructed against EI. The two responses play off one another: objecting to the first puts pressure on one to accept the other. Taken together, the two responses have important ramifications for how we answer the Evidence Question, and how we think about evidence in general. (shrink)

The paper proposes a novel account of justified evidence resistance. When S inquires as to whether p is the case, S resists available counterevidence e if S either fails to countenance e or is insensitive to e’s probative force. S is justified in resisting available counterevidence e if and only if e is irrelevant.