In recent years, several philosophers have argued that the a priori/a posteriori distinction is a legitimate distinction but does not carve at the epistemological joints and is theoretically unimportant. In this paper, I do two main things. First, I respond to the most prominent recent challenge to the significance of the a priori/a posteriori distinction – the central argument in Williamson (2013). Second, I discuss the question of what the theoretical significance of the a priori/a posteriori distinction is. -/- I (...) first present the a priori/a posteriori distinction as it is typically developed. I then turn to Williamson’s challenge to the significance of the distinction. Williamson points out that we often use the same cognitive mechanisms in coming to have a priori and a posteriori knowledge. So how could it be, asks Williamson, that there is a “deep epistemological difference” between the two? In response to this challenge, I argue that there is an important disanalogy between Williamson’s central example of a case of a priori knowledge and his central example of a case of a posteriori knowledge. Although the beliefs in the two cases are formed in similar ways, the ways in which their justification can be defeated are different. This suggests that there is an important epistemological difference between the two cases, one that cannot be captured in terms of the cognitive mechanisms used to form the beliefs. -/- Although Williamson’s argument is unsuccessful, there remains the question of just what the theoretical significance of the a priori/a posteriori distinction is. I argue that the point of the distinction is not to enable us to represent some joint in nature, but rather to help us to identify epistemological problem cases. We understand – more-or-less – the epistemology of simple perceptual knowledge. The epistemology of non-perceptual knowledge is far less clear. The purpose of labeling a case of knowledge as a priori is to claim that its epistemology should not be assimilated to the epistemology of perception. Instead, it is something of a puzzle case. -/- This proposal has an important implication. There are several ways in which a case of knowledge can be different from a simple case of perceptual knowledge. Two differences are perhaps the most important: (i) the justification of the belief does not involve phenomenality, and (ii) the belief does not stand in a causal relation to what the belief is about. When beliefs about some subject matter fit either (i) or (ii), an epistemological puzzle arises. So there is more than one kind of epistemological puzzle to solve. This suggests that there is an important theoretical role for (at least) two distinctions in the ballpark of the traditional a priori/a posteriori distinction. (shrink)

How is moral knowledge possible? This paper defends the anti-Humean thesis that we can acquire moral knowledge by deduction from wholly non-moral premises. According to Hume’s Law, as it has become known, we cannot deduce an ‘ought’ from an ‘is’, since it is “altogether inconceivable how this new relation can be a deduction from others, which are entirely different from it” (Hume, 1739, 3.1.1). This paper explores the prospects for a deductive theory of moral knowledge that rejects Hume’s Law.

In this chapter I analyse an objection to phenomenal conservatism to the effect that phenomenal conservatism is unacceptable because it is incompatible with Bayesianism. I consider a few responses to it and dismiss them as misled or problematic. Then, I argue that this objection doesn’t go through because it rests on an implausible formalization of the notion of seeming-based justification. In the final part of the chapter, I investigate how seeming-based justification and justification based on one’s reflective belief that one (...) has a seeming interact with one another. (shrink)

This paper formulates some paradoxes of inductive knowledge. Two responses in particular are explored: According to the first sort of theory, one is able to know in advance that certain observations will not be made unless a law exists. According to the other, this sort of knowledge is not available until after the observations have been made. Certain natural assumptions, such as the idea that the observations are just as informative as each other, the idea that they are independent, and (...) that they increase your knowledge monotonically (among others) are given precise formulations. Some surprising consequences of these assumptions are drawn, and their ramifications for the two theories examined. Finally, a simple model of inductive knowledge is offered, and independently derived from other principles concerning the interaction of knowledge and counterfactuals. (shrink)

According to Fumerton in his "How Does Perception Justify Belief?", it is misleading or wrong to say that perception is a source of justification for beliefs about the external world. Moreover, reliability does not have an essential role to play here either. I agree, and I explain why in section 1, using novel considerations about evil demon scenarios in which we are radically deceived. According to Fumerton, when it comes to how sensations or experiences supply justification, they do not do (...) so on their own, and instead only do so only in conjunction with support for background beliefs about how the sensations or experiences are best explained. Here I disagree. In section 2, I first clarify the question of whether sensations or experiences provide justification on their own. I then respond to Fumerton’s arguments that use considerations about concept-possession and about how to close possible gaps between experience and truth. In section 3, I develop my main concern about his positive view, where that concern also brings out some of the merits of the view that experiences do justify beliefs about the external world on their own. (shrink)

There are few indulgences academics can crave more than to have their work considered and addressed by leading researchers in their field. We have been fortunate to have two outstanding philosophers from whose work we have learned a great deal give ours their thoughtful attention. Grappling with Stephen Yablo’s, and Juan Comesaña’s comments and criticisms has helped us gain a better understanding of our ideas as well as their shortcomings. We are extremely grateful to them for the attentiveness and seriousness (...) with which they have considered our arguments and to philosophical studies for giving us this opportunity. Given the substantive difference between the two response papers, there is not much beyond sincere gratitude that we can covey to them jointly. We will therefore address them in turn. (shrink)

I object to Markos Valaris’s thesis that reasoning requires a belief that your conclusion follows from your premisses. My counter-examples highlight the important but neglected role of suppositional reasoning in the basis of so much of what we know.

According to a traditional Cartesian epistemology of perception, perception does not provide one with direct knowledge of the external world. Instead, your immediate perceptual evidence is limited to facts about your own visual experience, from which conclusions about the external world must be inferred. Cartesianism faces well-known skeptical challenges. But this chapter argues that any anti-Cartesian view strong enough to avoid these challenges must license a way of updating one’s beliefs in response to anticipated experiences that seems diachronically irrational. To (...) avoid this result, the anti-Cartesian must either license an unacceptable epistemic chauvinism, or else claim that merely reflecting on one’s experiences defeats perceptual justification. This leaves us with a puzzle: Although Cartesianism faces problems, avoiding them brings a new set of problems. (shrink)

Extended Rationality: A Hinge Epistemology provides a novel account of the structure of epistemic justification. Its central claim builds upon Wittgenstein's idea in On Certainty that epistemic justifications hinge on some basic assumptions and that epistemic rationality extends to these very hinges. It exploits these ideas to address major problems in epistemology, such as the nature of perceptual justifications, external world skepticism, epistemic relativism, the epistemic status of basic logical laws, of the Principle of the Uniformity of Nature, of our (...) belief in the existence of the past and of other minds, and the nature of testimonial justification. Along the way, further technical issues, such as the scope of the Principle of Closure of epistemic operators under known entailment, the notion of transmission failure, and the existence of entitlements are addressed in new and illuminating ways. (shrink)

I review recent work on Phenomenal Conservatism, the position introduced by Michael Huemer according to which if it seems that P to a subject S, in the absence of defeaters S has thereby some degree of justification for believing P.

Here we challenge the orthodoxy according to which abduction is an a posteriori mode of inference. We start by providing a case study illustrating how abduction can justify a philosophical claim not justifiable by empirical evidence alone. While many grant abduction's epistemic value, nearly all assume that abductive justification is a posteriori, on grounds that our belief in abduction's epistemic value depends on empirical evidence about how the world contingently is. Contra this assumption, we argue, first, that our belief in (...) abduction’s epistemic value is not and could not be justified a posteriori, and second, that attention to the roles experience plays in abductive justification supports taking abduction to be an a priori mode of inference. We close by highlighting how our strategy for establishing the a priority of abduction positively contrasts with strategies in Bonjour (1998), Swinburne (2001), and Peacocke (2004) aiming to establish the a priority of certain ampliative modes of inference or abductive principles. (shrink)

Although Alston believed epistemically circular arguments were able to justify their conclusions, he was also disquieted by them. We will argue that Alston was right to be disquieted. We explain Alston’s view of epistemic circularity, the considerations that led him to accept it, and the purposes he thought epistemically circular arguments could serve. We then build on some of Alston’s remarks and introduce further limits to the usefulness of such arguments and introduce a new problem that stems from those limits. (...) The upshot is that adopting Alston’s view that epistemically circular arguments can be used to justify their conclusions is more costly than even he thought. (shrink)

According to Perceptual Fundamentalism we can have justified perceptual beliefs solely in virtue of having perceptual experiences with corresponding contents. Recently, it has been argued that Perceptual Fundamentalism entails that it is possible to gain an a priori justified belief that perception is reliable by engaging in a suppositional reasoning process of a priori bootstrapping. But I will show that Perceptual Fundamentalists are not committed to a priori bootstrapping being a rational reasoning process. On the most plausible versions of Perceptual (...) Fundamentalism, a priori bootstrapping cannot be used to rationally support anti-sceptical beliefs about the reliability of perception. Moreover, seeing why Perceptual Fundamentalists are not committed to a priori bootstrapping will help us to better understand the nature of the perceptual entitlements that Perceptual Fundamentalists posit, or at least should posit. (shrink)

The debate between exceptionalists and anti-exceptionalists about logic is often framed as concerning whether the justification of logical theories is a priori or a posteriori (for short: whether logic is a priori or a posteriori). As we substantiate (S1), this framing more deeply encodes the usual anti-exceptionalist thesis that logical theories, like scientific theories, are abductively justified, coupled with the common supposition that abduction is an a posteriori mode of inference, in the sense that the epistemic value of abduction is (...) (and, indeed, must be) a posteriori. In past work, however, we have argued that this common supposition is incorrect: abduction is an a priori mode of inference, in the sense that the epistemic value of abduction is (and indeed, must be) a priori (Biggs and Wilson 2017a, 2017b, 2019). After sketching our two main argumentative strategies for this conclusion (S2), we go on (S3) to consider its import on the proper understanding of anti-exceptionalism about logic. (shrink)

We have several intuitive paradigms of defeating evidence. For example, let E be the fact that Ernie tells me that the notorious pet Precious is a bird. This supports the premise F, that Precious can fly. However, Orna gives me *opposing* evidence. She says that Precious is a dog. Alternatively, defeating evidence might not oppose Ernie's testimony in that direct way. There might be other ways for it to weaken the support that Ernie's testimony gives me for believing F, without (...) the new evidence itself intuitively constituting reasons to believe one way or the other about Precious's flight ability. An example: Ursula tells me that Ernie has no idea what Precious's species is; he's just guessing. She may not herself want to or be in a position to weigh in about Precious's real species or flight ability. I call defeating evidence of this sort *undermining evidence. (shrink)

According to evidentialists about inferential justification, an agent’s evidence—and only her evidence—determines which inferences she would be justified in making, whether or not she in fact makes them. But there seem to be cases in which two agents would be justified in making different inferences from a shared body of evidence, merely in virtue of the different competences those agents possess. These sorts of cases suggest that evidence does not have the pride of place afforded to it by evidentialists; competence (...) seems to play at least as important a role as evidence in explaining which inferences an agent would be justified in making. -/- In this paper, I consider how two versions of evidentialism about inferential justification might try to account for the role of competence in inference, and I present problems specific to each version. I end by sketching and briefly defending an alternative to these evidentialist views, “inferential dogmatism”. While dogmatic views have gotten some attention in debates around non-inferential justification, they have largely been ignored in debates around inferential justification and are to that extent novel. (shrink)

Epistemic reasons are meant to provide justification for beliefs. In this paper, I will be concerned with the requirements that have to be met if reasons are to discharge this function. It is widely recognized, however, that only possessed reasons can justify beliefs and actions. But what are the conditions that have to be satisfied in order for one to possess reasons? I shall begin by motivating a particular condition, namely, the ‘treating’ requirement that has been deemed to be necessary (...) for possessing reasons. In Sect. 1, I explain and criticize some of the existing accounts of the treating requirement for reason-possession. In Sect. 2, I will suggest a dispositional account of reason-possession in which the treating condition features prominently. Section 3 will deal with the some of the consequences of this account for such issues as the structure of epistemic defeat, the immediacy of perceptual justification and logical knowledge. (shrink)

In the contemporary expanding literature on transmission failure and its connections with issues such as the Closure principle, the nature of perceptual warrant, Moore’s proof of an external world and the effectiveness of Humean scepticism, it has often been assumed that there is just one kind of it: the one made familiar by the writings of Crispin Wright and Martin Davies. Although it might be thought that one kind of failure is more than enough, Davies has recently challenged this view: (...) apparently, there are more ways in heaven and earth that warrant can fail to transmit across valid inference from one (set of) belief(s) to another, than have been dreamt of in philosophy so far. More specifically, Davies thinks that a second kind of transmission failure has to be countenanced. He connects each kind of failure of transmission of warrant with two different kinds of epistemic project, respectively, and with the exploration of whether the current dispute between conservatives such as Wright, and liberals such as Jim Pryor, on the nature of perceptual warrant, would have a bearing on them. I point out why Davies’s second kind of transmission failure is indeed no such thing. I then move on to canvass another kind of transmission failure, different from the one studied by both Wright and Davies, and dependent on an alternative conception of the structure of empirical warrants, which I dub “moderatism”. I then consider how this alternative notion of transmission failure fares with respect to Moore’s proof, its relationship with Wright’s kind of transmission failure and with the Closure principle. In closing, I defend it from criticisms that can be elicited from Pryor’s recent work. (shrink)