This paper examines lessons obtained by means of simulations in the form of agent-based models about the norms that are to guide disagreeing scientists. I focus on two types of epistemic and methodological norms: norms that guide one’s attitude towards one’s own theory, and norms that guide one’s attitude towards the opponent’s theory. Concerning I look into ABMs that have been designed to examine the context of peer disagreement. Here I challenge the conclusion that the given ABMs provide a support (...) for the so-called Steadfast Norm, according to which one is epistemically justified in remaining steadfast in their beliefs in face of disagreeing peers. I argue that the proposed models at best provide evidence for a weaker norm, which concerns methodological steadfastness. Concerning I look into ABMs aimed at examining epistemic effects of scientific interaction. Here I argue that the models provide diverging suggestions and that the link between each ABM and the type of represented inquiry is still missing. Moreover, I examine alternative strategies of arguing in favor of the benefits of scientific interaction, relevant for contemporary discussions on scientific pluralism. (shrink)

Predictable polarization is everywhere: we can often predict how people’s opinions, including our own, will shift over time. Extant theories either neglect the fact that we can predict our own polarization, or explain it through irrational mechanisms. They needn’t. Empirical studies suggest that polarization is predictable when evidence is ambiguous, that is, when the rational response is not obvious. I show how Bayesians should model such ambiguity and then prove that—assuming rational updates are those which obey the value of evidence—ambiguity (...) is necessary and sufficient for the rationality of predictable polarization. The main theoretical result is that there can be a series of such updates, each of which is individually expected to make you more accurate, but which together will predictably polarize you. Polarization results from asymmetric increases in accuracy. This mechanism is not only theoretically possible, but empirically plausible. I argue that cognitive search—searching a cognitively accessible space for a particular item—often yields asymmetrically ambiguous evidence, I present an experiment supporting its polarizing effects, and I use simulations to show how it can explain two of the core causes of polarization: confirmation bias and the group polarization effect. (shrink)

Do people tend to be overconfident? Many think so. They’ve run studies on whether people are calibrated: whether their average confidence in their opinions matches the proportion of those opinions that are true. Under certain conditions, people are systematically ‘over-calibrated’—for example, of the opinions they’re 80% confident in, only 60% are true. From this empirical over-calibration, it’s inferred that people are irrationally overconfident. My question: When and why is this inference warranted? Answering it requires articulating a general connection between being (...) rational and being right—something extant studies have not done. I show how to do so using the notion of deference. This provides a theoretical foundation for calibration research, but also reveals a flaw: the connection between being rational and being right is much weaker than is standardly assumed, since rational people can often be expected to be miscalibrated. Thus we can’t test whether people are overconfident by simply testing whether they are over-calibrated; instead, we must try to predict the rational deviations from calibration, and then compare those predictions to people’s performance. I show how this can be done—and that doing so complicates the interpretation of robust empirical effects. (shrink)

Many have claimed that whenever an investigation might provide evidence for a claim, it might also provide evidence against it. Similarly, many have claimed that your credence should never be on the edge of the range of credences that you think might be rational. Surprisingly, both of these principles imply that you cannot rationally be modest: you cannot be uncertain what the rational opinions are.

Assume that it is your evidence that determines what opinions you should have. I argue that since you should take peer disagreement seriously, evidence must have two features. (1) It must sometimes warrant being modest: uncertain what your evidence warrants, and (thus) uncertain whether you’re rational. (2) But it must always warrant being guided: disposed to treat your evidence as a guide. Surprisingly, it is very difficult to vindicate both (1) and (2). But diagnosing why this is so leads to (...) a proposal—Trust—that is weak enough to allow modesty but strong enough to yield many guiding features. In fact, I claim that Trust is the Goldilocks principle—for it is necessary and sufficient to vindicate the claim that you should always prefer to use free evidence. Upshot: Trust lays the foundations for a theory of disagreement and, more generally, an epistemology that permits self-doubt—a modest epistemology. (shrink)

While many have argued that moral disagreement poses a challenge to moral knowledge, the precise nature of this challenge is controversial. Indeed, in the moral epistemology literature, there are many different versions of ‘the’ argument from moral disagreement to moral scepticism. This paper contributes to this vast literature on moral disagreement by arguing for two theses: 1. All (or nearly all) moral disagreement arguments share an underlying structure; and, 2. All moral disagreement arguments that satisfy this underlying structure cannot establish (...) moral scepticism because this underlying structure leads to a previously unrecognized reductio ad absurdum. In short, I argue that this reductio argument (very likely) refutes all versions of the moral disagreement to moral scepticism argument in one fell swoop. (shrink)

The Fallibility Norm—the claim that we ought to take our fallibility into account when managing our beliefs—appears to conflict with several other compelling epistemic norms. To shed light on these apparent conflicts, I distinguish two kinds of norms: norms of perfection and norms of compensation. Roughly, norms of perfection tell us how agents ought to behave if they’re to be perfect; norms of compensation tell us how imperfect agents ought to behave in order to compensate for their imperfections. I argue (...) that the Fallibility Norm is a norm of compensation, and that thinking of it like this helps us make progress in debates surrounding disagreement, higher-order evidence, and coherence. (shrink)

Higher-order defeat occurs when one loses justification for one's beliefs as a result of receiving evidence that those beliefs resulted from a cognitive malfunction. Several philosophers have identified features of higher-order defeat that distinguish it from familiar types of defeat. If higher-order defeat has these features, they are data an account of rational belief must capture. In this article, I identify a new distinguishing feature of higher-order defeat, and I argue that on its own, and in conjunction with the other (...) distinguishing features, it favors an account of higher-order defeat grounded in non-evidential, ‘state-given reasons’ for belief. (shrink)

The “Evidentialist Dictum” says we must believe what our evidence supports, and the “Fallibility Norm” says we must take our fallibility into account when managing our beliefs. This paper presents a problem for the Evidentialist Dictum based in the Fallibility Norm and a particular conception of evidential support. It then addresses two novel Evidentialist responses to this problem. The first response solves the problem by claiming that fallibility information causes “evidence-loss.” In addition to solving the problem, this response appears to (...) explain what’s wrong with certain illegitimate dismissals of misleading evidence. However, this explanation opens it up to objections. Next, I consider and pose challenges to an Evidentialist strategy that attempts to solve the problem by converting accounts of fallibility’s epistemic significance for rational belief into principles of evidential support. I conclude by sketching a solution that allows us to capture what’s true in the Evidentialist Dictum and the Fallibility Norm. (shrink)

While the epistemic significance of disagreement has been a popular topic in epistemology for at least a decade, little attention has been paid to logical disagreement. This monograph is meant as a remedy. The text starts with an extensive literature review of the epistemology of (peer) disagreement and sets the stage for an epistemological study of logical disagreement. The guiding thread for the rest of the work is then three distinct readings of the ambiguous term ‘logical disagreement’. Chapters 1 and (...) 2 focus on the Ad Hoc Reading according to which logical disagreements occur when two subjects take incompatible doxastic attitudes toward a specific proposition in or about logic. Chapter 2 presents a new counterexample to the widely discussed Uniqueness Thesis. Chapters 3 and 4 focus on the Theory Choice Reading of ‘logical disagreement’. According to this interpretation, logical disagreements occur at the level of entire logical theories rather than individual entailment-claims. Chapter 4 concerns a key question from the philosophy of logic, viz., how we have epistemic justification for claims about logical consequence. In Chapters 5 and 6 we turn to the Akrasia Reading. On this reading, logical disagreements occur when there is a mismatch between the deductive strength of one’s background logic and the logical theory one prefers (officially). Chapter 6 introduces logical akrasia by analogy to epistemic akrasia and presents a novel dilemma. Chapter 7 revisits the epistemology of peer disagreement and argues that the epistemic significance of central principles from the literature are at best deflated in the context of logical disagreement. The chapter also develops a simple formal model of deep disagreement in Default Logic, relating this to our general discussion of logical disagreement. The monograph ends in an epilogue with some reflections on the potential epistemic significance of convergence in logical theorizing. (shrink)

There is a strong presumption that mental disorder injures a person's autonomy, understood as a set of capacities and as an ideal condition of agency which is worth striving for. However, recent multidimensional approaches to autonomy have revealed a greater diversity in ways of being autonomous than has previously been appreciated. This presumption, then, risks wrongly dismissing variant, neuro-atypical sorts of autonomy as non-autonomy. This is both an epistemic error, which impairs our understanding of autonomy as a phenomenon, and a (...) moral error, which withholds recognition and respect that autonomous agents are due. I argue that careful attention to the different 'shapes' of agent's autonomy reveals that there are indeed distinctive kinds of neuro-atypical autonomy that are widely mistaken for non-autonomy. This project argues for two propositions. First, that there is a kind of autonomy, with a distinctive shape and texture, available to bipolar agents. This is a variant sort of autonomy, but not a defective or deficient sort. It is the ideal of autonomy that it is worth bipolar agents striving for, given the range and intensity of experiences that they will have to confront. Whilst bipolar autonomy will look unlike more neurotypical kinds of autonomy, it continues to be owed recognition. The second proposition is that we should understand the ideal of autonomy to be both pluralist and highly context sensitive. Given the range of starting points from which agents will strive to an ideal of autonomy, there will be some variation in the ideals worth striving for. The variation in ideals will reflect the existential realities they are local to. Theory of autonomy must be adapted to recognise bipolar, and other neuro-atypical, kinds of autonomy, and to reflect this wider pluralism. These propositions will be argued for with careful attention to the experiences and agency of people living with bipolar, or related, disorders. Understanding the ways that manic or depressive episodes, and the shifts between them, alter and apply pressure to our agency will inform an account of the distinctively bipolar autonomy that can be built on top of it. (shrink)

Thinking about misleading higher-order evidence naturally leads to a puzzle about epistemic rationality: If one’s total evidence can be radically misleading regarding itself, then two widely-accepted requirements of rationality come into conflict, suggesting that there are rational dilemmas. This paper focuses on an often misunderstood and underexplored response to this (and similar) puzzles, the so-called conflicting-ideals view. Drawing on work from defeasible logic, I propose understanding this view as a move away from the default metaepistemological position according to which rationality (...) requirements are strict and governed by a strong, but never explicitly stated logic, toward the more unconventional view, according to which requirements are defeasible and governed by a comparatively weak logic. When understood this way, the response is not committed to dilemmas. (shrink)

When we get evidence that tells us our belief-forming mechanisms may not be reliable this presents a thorny set of questions about whether and how to revise our original belief. This article analyzes aspects of the problem and a variety of approaches to its solution.

This article examines the central epistemological issues tied to the recognition of disagreement.

This article discusses conceptions of modesty and humility and their key features. It gives a brief historical overview of debates about whether or not they’re really virtues at all. It also discusses theories of modesty and humility that root them in the presence or absence of particular beliefs, emotions, desires, and attention. it also discusses related phenomena in epistemology: rational limits on self-ascription of error, attitudes to disagreement, and openness to alternative views.

The article addresses the question of how should scientific peers revise their beliefs (if at all) upon recognized disagreement. After presenting the basics of peer disagreement in sections 1 and 2, we focus, in section 3, on a concrete case of scientific disagreement, to wit, the dispute over the evidential status of randomized control trials in medical practice. The examination of this case motivates the idea that some scientific disagreements permit a steadfast reaction. In section 4, we support this conclusion (...) by providing a normative argument in the same direction; if we are correct, typical reasons for conciliation are absent in this kind of scientific disagreements. (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)

Abstract. This paper argues that the “Argument from Moral Peer Disagreement” fails to make a case for widespread moral skepticism. The main reason for this is that the argument rests on a too strong assumption about the normative significance of peer disagreement (and higher-order evidence more generally). In order to demonstrate this, I distinguish two competing ways in which one might explain higher-order defeat. According to what I call the “Objective Defeat Explanation” it is the mere possession of higher-order evidence (...) that explains defeat. I argue that this type of explanation is problematic and that it at best collapses into another explanation I call the “Subjective Defeat Explanation”. According to this explanation, it is coming to believe that one’s belief fails to be rational that explains defeat. Then I go on to argue that the Subjective Defeat Explanation is able to provide a straightforward explanation of higher-order defeat but that it entails that peer disagreement (and higher-order evidence more generally) only contingently gives rise to defeat, and importantly, that the condition it is contingent upon is very often not satisfied when it comes to moral peer disagreement specifically. As a result, it appears that moral knowledge is seldom threatened by moral peer disagreement. (shrink)

Sometimes we make mistakes, even when we try to do our best. When those mistakes are about normative matters, such as what is required, this leads to a puzzle. This puzzle arises from the possibility of misleading evidence about what rationality requires. I argue that the best way to solve this puzzle is to distinguish between two kinds of evaluation: requirement and appraisal. The strategy I defend connects three distinct debates in epistemology, ethics, and normativity: the debate over how our (...) theories of epistemic rationality should accommodate misleading evidence, the debate over the relationship between complying with requirements and deserving particular appraisals, and the debate over whether normative ignorance can excuse. Part 1 shows how three apparently plausible claims about epistemic rationality generate a puzzle when agents have misleading evidence about what rationality requires. Part 2 solves this puzzle by distinguishing between evaluations of requirement and appraisal and rejecting the idea that one is required to conform to the Enkratic Principle. I argue instead that complying with the Enkratic Principle provides defeasible evidence that the agent should be positively appraised. One of the consequences of this solution is that false normative beliefs can sometimes excuse agents from negative appraisal they would otherwise deserve for violating requirements. Part 3 defends the view that false normative belief can sometimes excuse against the rival views that false normative belief always excuses, and that false normative belief never excuses. I argue that false normative belief can sometimes excuse violations of requirements, when it is the case that the agent has done what it is reasonable to expect of her. (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 introduce a family of rules for adjusting one's credences in response to learning the credences of others. These rules have a number of desirable features. 1. They yield the posterior credences that would result from updating by standard Bayesian conditionalization on one's peers' reported credences if one's likelihood function takes a particular simple form. 2. In the simplest form, they are symmetric among the agents in the group. 3. They map neatly onto the familiar Condorcet voting results. 4. They (...) preserve shared agreement about independence in a wide range of cases. 5. They commute with conditionalization and with multiple peer updates. Importantly, these rules have a surprising property that we call synergy - peer testimony of credences can provide mutually supporting evidence raising an individual's credence higher than any peer's initial prior report. At first, this may seem to be a strike against them. We argue, however, that synergy is actually a desirable feature and the failure of other updating rules to yield synergy is a strike against them. (shrink)

Recent work has argued that there may be cases where no attitude – including withholding – is rationally permissible. In this paper, I consider two such epistemic dilemmas, John Turri’s Dilemma from Testimony and David Alexander’s Dilemma from Doubt. Turri presents a case where one’s only evidence rules out withholding (without warranting belief or disbelief). Alexander presents a case where higher order doubt means one must withhold judgment over whether withholding judgment is rational. In both cases, the authors conclude that (...) no doxastic attitude is warranted. In this paper, I argue against the possibility of these epistemic dilemmas. I argue that withholding cannot be irrational in either case. But meditating on the dilemmas gives us an important – and overlooked – insight into the nature of rational withholding. First, rational withholding is a function of evidence failing to sufficiently support belief or disbelief. As a result, withholding is not symmetrical to belief and disbelief. Second, there can be two distinct grounds for rational withholding. First, propositional withholding, which arises when our evidence does not support belief or disbelief in p. And second, doxastic withholding, which arises when we cannot determine whether our evidence supports belief or disbelief in p. Accepting two grounds of rational withholding licenses a kind of Weak Permissivism. But this Weak Permissivism should not be troubling to anyone. (shrink)

I argue with my friends a lot. That is, I offer them reasons to believe all sorts of philosophical conclusions. Sadly, despite the quality of my arguments, and despite their apparent intelligence, they don’t always agree. They keep insisting on principles in the face of my wittier and wittier counterexamples, and they keep offering their own dull alleged counterexamples to my clever principles. What is a philosopher to do in these circumstances? (And I don’t mean get better friends.) One popular (...) answer these days is that I should, to some extent, defer to my friends. If I look at a batch of reasons and conclude p, and my equally talented friend reaches an incompatible conclusion q, I should revise my opinion so I’m now undecided between p and q. I should, in the preferred lingo, assign equal weight to my view as to theirs. This is despite the fact that I’ve looked at their reasons for concluding q and found them wanting. If I hadn’t, I would have already concluded q. The mere fact that a friend (from now on I’ll leave off the qualifier ‘equally talented and informed’, since all my friends satisfy that) reaches a contrary opinion should be reason to move me. Such a position is defended by Richard Feldman (2006a, 2006b), David Christensen (2007) and Adam Elga (forthcoming). This equal weight view, hereafter EW, is itself a philosophical position. And while some of my friends believe it, some of my friends do not. (Nor, I should add for your benefit, do I.) This raises an odd little dilemma. If EW is correct, then the fact that my friends disagree about it means that I shouldn’t be particularly confident that it is true, since EW says that I shouldn’t be too confident about any position on which my friends disagree. But, as I’ll argue below, to consistently implement EW, I have to be maximally confident that it is true. So to accept EW, I have to inconsistently both be very confident that it is true and not very confident that it is true. This seems like a problem, and a reason to not accept EW.. (shrink)

In this thesis, I will explore the epistemological evolutionary debunking arguments in meta-ethics. I will defend these arguments by accomplishing two tasks: I will offer the best way to understand the EDA and I will also respond to two strongest objections to the EDA. Firstly, in Part I of this thesis, I will offer my account of how the EDA should be best formulated. I will start from how evolution has significantly influenced our moral beliefs. I will then explain why, (...) due to their evolutionary origin, our moral beliefs are not tracking the moral truth reliably. Furthermore, I will argue that the fact that our moral beliefs are not tracking the moral truth also provides an undercutting and a higher-order defeater for those beliefs. As a result, I will conclude that the epistemic status of our moral beliefs is undermined because of these two kinds of defeaters. Secondly, in Part II of this thesis, I will turn my attention to the two strongest objections to the EDA – the Conceptual Truth Objection and the Third Factor Objection. I will first offer two responses to the Conceptual Truth Objection and, based on these two responses, I will argue that the Conceptual Truth Objection fails as a challenge to the EDA. I will then also argue that there currently doesn’t exist an acceptable version of the Third Factor Objection and it is also unlikely that such a version could be constructed in the future. I will finally conclude that both objections are problematic and they are thus unable to give us reason to doubt the EDA. (shrink)

Despite its central role in our cognitive lives, rational belief revision has received relatively little attention from epistemologists. This dissertation begins to fill that absence. In particular, we explore the phenomenon of defeasible epistemic justification, i.e., justification that can be lost as well as gained by epistemic agents. We begin by considering extant theories of defeat, according to which defeaters are whatever cause a loss of justification or things that somehow neutralize one's reasons for belief. Both of these theories are (...) both extensionally and explanatorily inadequate and, so, are rejected. We proceed to develop a novel theory of defeat according to which defeaters are reasons against belief. According to this theory, the dynamics of justification are explained by the competition between reasons for and reasons against belief. We find that this theory not only handles the counter-examples that felled the previous theories but also does a fair job in explaining the various aspects of the phenomenon of defeat. Furthermore, this theory accomplishes this without positing any novel entities or mechanisms; according to this theory, defeaters are epistemic reasons against belief, the mirror image of our epistemic reasons for belief, rather than sui generis entities. (shrink)

This paper argues that higher-order doubt generates an epistemic dilemma. One has a higher-order doubt with regards to P insofar as one justifiably withholds belief as to what attitude towards P is justified. That is, one justifiably withholds belief as to whether one is justified in believing, disbelieving, or withholding belief in P. Using the resources provided by Richard Feldman’s recent discussion of how to respect one’s evidence, I argue that if one has a higher-order doubt with regards to P, (...) then one is not justified in having any attitude towards P. Otherwise put: No attitude towards the doubted proposition respects one’s higher-order doubt. I argue that the most promising response to this problem is to hold that when one has a higher-order doubt about P, the best one can do to respect such a doubt is to simply have no attitude towards P. Higher-order doubt is thus much more rationally corrosive than non-higher-order doubt, as it undermines the possibility of justifiably having any attitude towards the doubted proposition. (shrink)

We often get reason to doubt the reliability of some of our own reasoning. The rational response to such evidence would seem to depend on how reliable one should estimate that reasoning to be. Independence principles constrain that reliability-assessment, to prevent question-begging reliance on the very reasoning being assessed. But this has consequences some find disturbing: can it be rational for an agent to bracket some of her reasons—which she may, after all, be assessing impeccably? So several arguments have been (...) offered against the very idea of an Independence principle. This paper argues that looking closely at these arguments actually strengthens the case for Independence, and yields some guidance in meeting a formidable challenge for Independence-defenders: formulating the principle in an adequate way. (shrink)

This paper concentrates on a particular sort of case where it’s plausible that epistemic requirements can conflict: cases where an agent’s higher-order evidence supports doubting her reliability in reacting to her ordinary evidence. Conflicting epistemic requirements can be seen as generating epistemic dilemmas. The paper examines two ways that people have sought to recognize conflicting requirements without allowing them to generate epistemic dilemmas: separating epistemic norms into two different varieties, and positing rational indeterminacy in cases where principles conflict. It argues (...) that these views incur costs, and that the sense in which they avoid dilemmas does not gain them an advantage over a view that simply recognizes dilemmas as a natural outgrowth of agents’ rational reflection on their own thinking. (shrink)

This lecture illustrates some of the theoretical richness that emerges from thinking about self-aware agents. It argues that taking self-awareness into account yields a picture of rational belief that is surprising, in a number of different, but interconnected, ways. The complexities it focuses on emerge most clearly in cases that involve so-called “higher-order evidence.”.

Responding rationally to the information that others disagree with one’s beliefs requires assessing the epistemic credentials of the opposing beliefs. Conciliatory accounts of disagreement flow in part from holding that these assessments must be independent from one’s own initial reasoning on the disputed matter. I argue that this claim, properly understood, does not have the untoward consequences some have worried about. Moreover, some of the difficulties it does engender must be faced by many less conciliatory accounts of disagreement.

Our main aims in this paper is to discuss and criticise the core thesis of a position that has become known as phenomenal conservatism. According to this thesis, its seeming to one that p provides enough justification for a belief in p to be prima facie justified (a thesis we label Standard Phenomenal Conservatism). This thesis captures the special kind of epistemic import that seemings are claimed to have. To get clearer on this thesis, we embed it, first, in a (...) probabilistic framework in which updating on new evidence happens by Bayesian conditionalization, and second, a framework in which updating happens by Jeffrey conditionalization. We spell out problems for both views, and then generalize some of these to non-probabilistic frameworks. The main theme of our discussion is that the epistemic import of a seeming (or experience) should depend on its content in a plethora of ways that phenomenal conservatism is insensitive to. (shrink)

This paper argues for extreme rational permissivism—the view that agents with identical evidence can rationally believe contradictory hypotheses—and a mild version of steadfastness. Agents can rationally come to different conclusions on the basis of the same evidence because their way of weighing the theoretic virtues may differ substantially. Nevertheless, in the face of disagreement, agents face considerable pressure to reduce their confidence. Indeed, I argue that agents often ought to reduce their confidence in the higher-order propositions that they know or (...) rationally believe disputed content. I argue, however, that when the subject matter is difficult, there is more flexibility for agents to simultaneously believe that p while withholding belief about whether such belief is rational or known. This allows for modest steadfastness on hard questions in, e.g., philosophy and religion. (shrink)

There is a growing interest in the foundations as well as the application of imprecise probability in contemporary epistemology. This dissertation is concerned with the application. In particular, the research presented concerns ways in which imprecise probability, i.e. sets of probability measures, may helpfully address certain philosophical problems pertaining to rational belief. The issues I consider are disagreement among epistemic peers, complete ignorance, and inductive reasoning with imprecise priors. For each of these topics, it is assumed that belief can be (...) modeled with imprecise probability, and thus there is a non-classical solution to be given to each problem. I argue that this is the case for peer disagreement and complete ignorance. However, I discovered that the approach has its shortcomings, too, specifically in regard to inductive reasoning with imprecise priors. Nevertheless, the dissertation ultimately illustrates that imprecise probability as a model of rational belief has a lot of promise, but one should be aware of its limitations also. (shrink)

A blindspot is a consistent but inaccessible proposition. For instance, I cannot know 'The test is on Friday but I do not know it'. No contradiction follows from the supposition that you know my blindspot. But could you know my blindspot if we are epistemic peers? Epistemic peers have the same evidence and reasoning ability. So either both peers know a proposition or both are ignorant. Since I cannot know my blindspot, neither can my peer. Thus the formal ignorance associated (...) with blindspots spreads to my peers. This contagion is used to improve a solution to the blindspot solution to the surprise test paradox. (shrink)

Hierarchies of evidence are an important and influential tool for appraising evidence in medicine. In recent years, hierarchies have been formally adopted by organizations including the Cochrane Collaboration [1], NICE [2,3], the WHO [4], the US Preventive Services Task Force [5], and the Australian NHMRC [6,7]. The development of such hierarchies has been regarded as a central part of Evidence-Based Medicine, a movement within healthcare which prioritises the use of epidemiological evidence such as that provided by Randomised Controlled Trials. Philosophical (...) work on the methodology of medicine has so far mostly focused on claims about the superiority of RCTs, and hence has largely neglected the questions of what hierarchies are, what assumptions they require, and how they affect clinical practice. This thesis shows that there is great variation in the hierarchies defended and in the interpretations they are, and can be, given. The interpretative assumptions made in using hierarchies are crucial to the content and defensibility of the underlying philosophical commitments concerning evidence and medical practice. Once this variation is been identified, it becomes clear that the little philosophical work that has been done so far affects only some hierarchies, under some interpretations. Modest interpretations offered by La Caze [11], conditional hierarchies like GRADE [12-14], and heuristic approaches such as that defended by Howick et al. [15,16] all survive previous philosophical criticism. This thesis extends previous criticisms by arguing that modest interpretations are so weak as to be unhelpful for clinical practice; that GRADE and similar conditional models omit clinically relevant information, such as information about variation in treatments’ effects and the causes of different responses to therapy; and that heuristic approaches lack the necessary empirical support. The conclusion is that hierarchies in general embed untenable philosophical assumptions: principally that information about average treatment effects backed by high-quality evidence can justify strong recommendations, and that the impact of evidence from individual studies can and should be appraised in isolation. Hierarchies are a poor basis for the application of evidence in clinical practice. The Evidence-Based Medicine movement should move beyond them and explore alternative tools for appraising the overall evidence for therapeutic claims. (shrink)

We are fallible, and knowledge of our fallibility has normative implications. But these normative implications appear to conflict with other compelling epistemic norms. We therefore appear to face a choice: reject fallibility-based norms or reject these other epistemic norms. I argue that there is a plausible third option: reconcile these two sets of norms. Once we properly understand the nature of each of these norms, we aren’t forced to reject either.

What if your peers tell you that you should disregard your perceptions? Worse, what if your peers tell you to disregard the testimony of your peers? How should we respond if we get evidence that seems to undermine our epistemic rules? Several philosophers have argued that some epistemic rules are indefeasible. I will argue that all epistemic rules are defeasible. The result is a kind of epistemic particularism, according to which there are no simple rules connecting descriptive and normative facts. (...) I will argue that this type of particularism is more plausible in epistemology than in ethics. The result is an unwieldy and possibly infinitely long epistemic rule — an Uber-rule. I will argue that the Uber-rule applies to all agents, but is still defeasible — one may get misleading evidence against it and rationally lower one’s credence in it. (shrink)

Building on recent formal work by Aleks Knoks, we explore how the idea that certain epistemic norms may be indeterminate could be implemented in a default logic.

Many epistemologists treat rationality and justification as the same thing. Those who don’t lack detailed accounts of the difference, leading their opponents to suspect that the distinction is an ad hoc attempt to safeguard their theories of justification. In this paper, I offer a new and detailed account of the distinction. The account is inspired by no particular views in epistemology, but rather by insights from the literature on reasons and rationality outside of epistemology. Specifically, it turns on a version (...) of the familiar distinction in meta-ethics between possessing apparent normative reasons (which may be merely apparent) and possessing objective normative reasons. The paper proceeds as follows. In §1, I discuss the history of indifference to the distinction between rationality and justification in epistemology and the striking contrast with meta-ethics. I introduced the distinction between apparent reasons and possessed objective reasons in §2 and provide a deeper basis for it in §3. I explain how the ideas extend to epistemology in §4 and explore the upshots for some central issues in §5. (shrink)