David Lewis (1941-2001) was Class of 1943 University Professor of Philosophy at Princeton University. His contributions spanned philosophical logic, philosophy of language, philosophy of mind, philosophy of science, metaphysics, and epistemology. In On the Plurality of Worlds, he defended his challenging metaphysical position, "modal realism." He was also the author of the books Convention, Counterfactuals, Parts of Classes, and several volumes of collected papers.

Recent authors have drawn attention to a new kind of defeating evidence commonly referred to as higher-order evidence. Such evidence works by inducing doubts that one’s doxastic state is the result of a flawed process – for instance, a process brought about by a reason-distorting drug. I argue that accommodating defeat by higher-order evidence requires a two-tiered theory of justification, and that the phenomenon gives rise to a puzzle. The puzzle is that at least in some situations involving higher-order defeaters (...) the correct epistemic rules issue conflicting recommendations. For instance, a subject ought to believe p, but she ought also to suspend judgment in p. I discuss three responses. The first resists the puzzle by arguing that there is only one correct epistemic rule, an Über-rule. The second accepts that there are genuine epistemic dilemmas. The third appeals to a hierarchy or ordering of correct epistemic rules. I spell out problems for all of these responses. I conclude that the right lesson to draw from the puzzle is that a state can be epistemically rational or justified even if one has what looks to be strong evidence to think that it is not. As such, the considerations put forth constitute a non question-begging argument for a kind of externalism. (shrink)

We use a new model of metarepresentational development to predict a cognitive deficit which could explain a crucial component of the social impairment in childhood autism. One of the manifestations of a basic metarepresentational capacity is a ‘ theory of mind ’. We have reason to believe that autistic children lack such a ‘ theory ’. If this were so, then they would be unable to impute beliefs to others and to predict their behaviour. This hypothesis was tested using Wimmer (...) and Perner’s puppet play paradigm. Normal children and those with Down’s syndrome were used as controls for a group of autistic children. Even though the mental age of the autistic children was higher than that of the controls, they alone failed to impute beliefs to others. Thus the dysfunction we have postulated and demonstrated is independent of mental retardation and specific to autism. (shrink)

I formulate a resilient paradox about epistemic rationality, discuss and reject various solutions, and sketch a way out. The paradox exemplifies a tension between a wide range of views of epistemic justification, on the one hand, and enkratic requirements on rationality, on the other. According to the enkratic requirements, certain mismatched doxastic states are irrational, such as believing p, while believing that it is irrational for one to believe p. I focus on an evidentialist view of justification on which a (...) doxastic state regarding a proposition p is epistemically rational or justified just in case it tracks the degree to which one’s evidence supports p. If it is possible to have certain kinds of misleading evidence, then evidentialism and the enkratic requirements come into conflict. Yet, both have been defended as platitudinous. After discussing and rejecting three solutions, I sketch an account that rejects the enkratic requirements, while nevertheless explaining our sense that epistemic akrasia is a distinct kind of epistemic failure. Central to the account is distinguishing between two evaluative perspectives, one having to do with the relevant kind of success, the other having to do with manifesting good dispositions. The problem with akratic subjects, I argue, is that they manifest dispositions to fail to correctly respond to a special class of conclusive and conspicuous reasons. (shrink)

Sometimes we get evidence of our own epistemic malfunction. This can come from finding out we’re fatigued, or have been drugged, or that other competent and well-informed thinkers disagree with our beliefs. This sort of evidence seems to seems to behave differently from ordinary evidence about the world. In particular, getting such evidence can put agents in a position where the most rational response involves violating some epistemic ideal.

For many epistemologists, and for many philosophers more broadly, it is axiomatic that rationality requires you to take the doxastic attitudes that your evidence supports. Yet there is also another current in our talk about rationality. On this usage, rationality is a matter of the right kind of coherence between one's mental attitudes. Surprisingly little work in epistemology is explicitly devoted to answering the question of how these two currents of talk are related. But many implicitly assume that evidence -responsiveness (...) guarantees coherence, so that the rational impermissibility of incoherence will just fall out of the putative requirement to take the attitudes that one's evidence supports, and so that coherence requirements do not need to be theorized in their own right, apart from evidential reasons. In this paper, I argue that this is a mistake, since coherence and evidence -responsiveness can in fact come into conflict. More specifically, I argue that in cases of misleading higher-order evidence, there can be a conflict between believing what one's evidence supports and satisfying a requirement that I call “inter-level coherence ”. This illustrates why coherence requirements and evidential reasons must be separated and theorized separately. (shrink)

Many assume that we can be responsible only what is voluntary. This leads to puzzlement about our responsibility for our beliefs, since beliefs seem not to be voluntary. I argue against the initial assumption, presenting an account of responsibility and of voluntariness according to which, not only is voluntariness not required for responsibility, but the feature which renders an attitude a fundamental object of responsibility (that the attitude embodies one’s take on the world and one’s place in it) also guarantees (...) that it could not be voluntary. It turns out, then, that, for failing to be voluntary, beliefs are a central example of the sort of thing for which we are most fundamentally responsible. (shrink)

Is there a distinctively epistemic kind of blame? It has become commonplace for epistemologists to talk about epistemic blame, and to rely on this notion for theoretical purposes. But not everyone is convinced. Some of the most compelling reasons for skepticism about epistemic blame focus on disanologies, or asymmetries, between the moral and epistemic domains. In this paper, I defend the idea that there is a distinctively epistemic kind of blame. I do so primarily by developing an account of the (...) nature of epistemic blame. My account draws on a prominent line of theorizing in moral philosophy that ties blame to our relationships with one another. I argue that with my account of epistemic blame on hand, the most compelling worries about epistemic blame can be deflated. There is a distinctively epistemic kind of blame. (shrink)

I develop and defend the view that subjects are necessarily psychologically able to revise their beliefs in response to relevant counter-evidence. Specifically, subjects can revise their beliefs in response to relevant counter-evidence, given their current psychological mechanisms and skills. If a subject lacks this ability, then the mental state in question is not a belief, though it may be some other kind of cognitive attitude, such as a supposition, an entertained thought, or a pretense. The result is a moderately revisionary (...) view of belief: while most mental states we thought were beliefs are beliefs, some mental states which we thought were beliefs are not beliefs. The argument for this view draws on two key claims: First, subjects are rationally obligated to revise their beliefs in response to relevant counter-evidence. Second, if some subject is rationally obligated to revise one of her mental states, then that subject can revise that mental state, given her current psychological mechanisms and skills. Along the way to defending these claims, I argue that rational obligations can govern activities which reflect on one’s rational character, whether or not those activities are under one’s voluntary control. I also show how the relevant version of epistemic ‘ought’ implies ‘can’ survives an objection which plagues other variants of the principle. (shrink)

This article argues that there can be epistemic dilemmas: situations in which one faces conflicting epistemic requirements with the result that whatever one does, one is doomed to do wrong from the epistemic point of view. Accepting this view, I argue, may enable us to solve several epistemological puzzles.

I defend the following version of the ought-implies-can principle: (OIC) by virtue of conceptual necessity, an agent at a given time has an (objective, pro tanto) obligation to do only what the agent at that time has the ability and opportunity to do. In short, obligations correspond to ability plus opportunity. My argument has three premises: (1) obligations correspond to reasons for action; (2) reasons for action correspond to potential actions; (3) potential actions correspond to ability plus opportunity. In the (...) bulk of the paper I address six objections to OIC: three objections based on putative counterexamples, and three objections based on arguments to the effect that OIC conflicts with the is/ought thesis, the possibility of hard determinism, and the denial of the Principle of Alternate Possibilities. (shrink)

This paper provides a critical overview of recent work on epistemic blame. The paper identifies key features of the concept of epistemic blame and discusses two ways of motivating the importance of this concept. Four different approaches to the nature of epistemic blame are examined. Central issues surrounding the ethics and value of epistemic blame are identified and briefly explored. In addition to providing an overview of the state of the art of this growing but controversial field, the paper highlights (...) areas where future work is needed. (shrink)

Conciliationism holds that disagreement of apparent epistemic peers often substantially undermines rational confidence in our opinions. Uniqueness principles say that there is at most one maximally rational doxastic response to any given batch of total evidence. The two views are often thought to be tightly connected. This paper distinguishes two ways of motivating conciliationism, and two ways that conciliationism may be undermined by permissive accounts of rationality. It shows how conciliationism can flourish under certain strongly permissive accounts of rationality. This (...) occurs when the motivation for conciliationism does not come from taking disagreement as evidence of one's own rational failings. However, divorcing the motive for conciliating from worries about rationality does not remove a feature of conciliationism that some find troubling: that conciliationism can lead to cases of “rational toxicity,” in which the most rational response to one's evidence involves violating some rational ideal. (shrink)

It would be good to have a Bayesian decision theory that assesses our decisions and thinking according to everyday standards of rationality — standards that do not require logical omniscience (Garber 1983, Hacking 1967). To that end we develop a “fragmented” decision theory in which a single state of mind is represented by a family of credence functions, each associated with a distinct choice condition (Lewis 1982, Stalnaker 1984). The theory imposes a local coherence assumption guaranteeing that as an agent's (...) attention shifts, successive batches of "obvious" logical information become available to her. A rule of expected utility maximization can then be applied to the decision of what to attend to next during a train of thought. On the resulting theory, rationality requires ordinary agents to be logically competent and to often engage in trains of thought that increase the unification of their states of mind. But rationality does not require ordinary agents to be logically omniscient. (shrink)

Marcus argues that moral dilemmas are real, but that they are not the result of inconsistent moral principles. Moral principles are consistent just in case there is some world where all principles are 'obeyable.' They are inconsistent just in case there is no world where all are 'obeyable.' What this logical point is meant to show is that moral dilemmas do not make moral codes inconsistent. She also discusses guilt, and argues that guilt is still appropriate even in cases of (...) conflict, even when the agent thinks the right thing to do is clear. (shrink)

N.B. Dr Bykvist is now based at the Faculty of Philosophy, University of Oxford. The full-text of this article is not currently available in ORA, but you may be able to access the article via the publisher copy link on this record page.

Polysemous concepts with multiple related meanings pervade natural languages, yet some philosophers argue that we should eliminate them to avoid miscommunication and pointless debates in scientific discourse. This paper defends the legitimacy of polysemous concepts in science against this eliminativist challenge. My approach analyses such concepts as patchworks with multiple scale-dependent, technique-involving, domain-specific and property-targeting uses (patches). I demonstrate the generality of my approach by applying it to "hardness" in materials science, "homology" in evolutionary biology, "gold" in chemistry and "cortical (...) column" in neuroscience. Such patchwork concepts are legitimate if the techniques used to apply them produce reliable results, the domains to which they are applied are homogenous, and the properties they refer to are significant to describe, classify or explain the behavior of entities in the extension of the concept. By following these normative constraints, researchers can avoid miscommunication and pointless debates without having to eliminate polysemous patchwork concepts in scientific discourse. (shrink)

Mindreading (or folk psychology, Theory of Mind, mentalizing) is the capacity to represent and reason about others’ mental states. The Simulation Theory (ST) is one of the main approaches to mindreading. ST draws on the common-sense idea that we represent and reason about others’ mental states by putting ourselves in their shoes. More precisely, we typically arrive at representing others’ mental states by simulating their mental states in our own mind. This entry offers a detailed analysis of ST, considers theoretical (...) arguments and empirical data in favour of and against it, discusses its philosophical implications, and illustrates some alternatives to it. (shrink)

A principle that many have found attractive is one that goes by the name “'Ought' Implies 'Can'.” According to this principle, one morally ought to do something only if one can do it. This essay has two goals: to show that the principle is false and to undermine the motivations that have been offered for it. Toward the end, a proposal about moral obligation according to which something like a restricted version of 'Ought' Implies 'Can' is true is floated. Though (...) no full-fledged argument for this proposal is offered, that it fits with a rather natural and intuitive picture of the structure of morality and seems to explain certain salient features of the debate over whether the principle is true, goes some way toward recommending it. (shrink)

Many philosophers claim that it cannot be the case that a person ought to perform an action if this person cannot perform this action. However, most of these philosophers do not give arguments for the truth of this claim. In this paper, I argue that it is plausible to interpret this claim in such a way that it is entailed by the claim that there cannot be a reason for a person to perform an action if it is impossible that (...) this person will perform this action. I then give three arguments for the truth of the latter claim, which are also arguments for the truth of the former claim as I interpret it. (shrink)

Lemmon argues that dilemmas occur between classes of 'oughts;' duties, obligations, and moral principles. He claims that there are not conflicts within each class, presumably because he is a utilitarian, and thinks that moral principles will always be univocal.

It is often thought that judgments about what we ought to do are limited by judgments about what we can do, or that “ought implies can.” We conducted eight experiments to test the link between a range of moral requirements and abilities in ordinary moral evaluations. Moral obligations were repeatedly attributed in tandem with inability, regardless of the type (Experiments 1–3), temporal duration (Experiment 5), or scope (Experiment 6) of inability. This pattern was consistently observed using a variety of moral (...) vocabulary to probe moral judgments and was insensitive to different levels of seriousness for the consequences of inaction (Experiment 4). Judgments about moral obligation were no different for individuals who can or cannot perform physical actions, and these judgments differed from evaluations of a non-moral obligation (Experiment 7). Together these results demonstrate that commonsense morality rejects the “ought implies can” principle for moral requirements, and that judgments about moral obligation are made independently of considerations about ability. By contrast, judgments of blame were highly sensitive to considerations about ability (Experiment 8), which suggests that commonsense morality might accept a “blame implies can” principle. (shrink)

William Alston’s argument against the deontological conception of epistemic justification is a classic—and much debated—piece of contemporary epistemology. At the heart of Alston’s argument, however, lies a very simple mistake which, surprisingly, appears to have gone unnoticed in the vast literature now devoted to the argument. After having shown why some of the standard responses to Alston’s argument don’t work, we elucidate the mistake and offer a hypothesis as to why it has escaped attention.

This paper presents a puzzle about justification and withholding. The puzzle arises in a special case where experts advise us to not withhold judgment. My main thesis is simply that the puzzle is genuinely a puzzle, and so leads us to rethink some common assumptions in epistemology, specifically assumptions about the nature of justification and doxastic attitudes. Section 1 introduces the common assumptions. Section 2 presents the puzzle case. Section 3 assesses the puzzle case. Section 4 explains the choice we're (...) faced with. Sections 5 and 6 consider and reject some proposed solutions, and in the process refine and clarify the choice we're faced with. Section 7 considers and rejects a miscellany of different proposed solutions. (shrink)

We tend to prescribe and appraise doxastic states in terms that are broadly deontic. According to a simple argument, such prescriptions and appraisals are improper, because they wrongly presuppose that our doxastic states are voluntary. One strategy for resisting this argument, recently endorsed by a number of philosophers, is to claim that our doxastic states are in fact voluntary (This strategy has been pursued by Steup 2008 ; Weatherson 2008 ). In this paper I argue that this strategy is neither (...) successful nor necessary. Our doxastic states are not voluntary in any interesting sense. But once we see why our doxastic states are not voluntary, we can also see that there is no apparent reason to think that deontic prescriptions and appraisals—epistemic ones, at any rate—presuppose doxastic voluntarism. Indeed, there is good reason to deny that they do so. Finally, I diagnose the misleading attraction of the idea that what I call ‘epistemic deontology’ presupposes doxastic voluntarism. (shrink)

According to the received account of guilt in the philosophical literature, one cannot feel guilt unless one takes oneself to have done something morally wrong. But ordinary people feel guilt in many cases in which they do not take themselves to have done anything morally wrong. In this paper, I focus on one kind of guilt without perceived wrongdoing, guilt about being merely causally responsible for a bad state-of-affairs. I go on to present a novel account of guilt that explains (...) guilt about mere causal responsibility, according to which guilt represents part of the self as bound up with what is bad. (shrink)

This paper is about epistemic dilemmas, i.e., cases in which one is doomed to have a doxastic attitude that is rationally impermissible no matter what. My aim is to develop and defend a position according to which there can be genuine rational indeterminacy; that is, it can be indeterminate which principles of rationality one should satisfy and thus indeterminate which doxastic attitudes one is permitted or required to have. I am going to argue that this view can resolve epistemic dilemmas (...) in a systematic way while also enjoying some important advantages over its rivals. (shrink)

Let us say that a normative conflict is a situation in which an agent ought to perform an action A, and also ought to perform an action B, but in which it is impossible for the agent to perform both A and B. Not all normative conflicts are moral conflicts, of course. It may be that the agent ought to perform the action A for reasons of personal generosity, but ought to perform the action B for reasons of prudence: perhaps (...) A involves buying a lavish gift for a friend, while B involves depositing a certain amount of money in the bank. In general, our practical deliberation is shaped by a concern with a variety of morally neutral goods—not just generosity and prudence, but any number of others, such as etiquette, aesthetics, fun—many of which are capable of providing conflicting reasons for action. I mention these ancillary values in the present setting, however, only to put them aside. We will be concerned here, not with normative conflicts more generally, but precisely with moral conflicts—situations in which, even when our attention is restricted entirely to moral reasons for action, it is nevertheless true that an agent ought to do A and ought to do B, where it is impossible to do both. (shrink)

Every kind of ‘ought’ implies some kind of ‘can’ – but there are many kinds of ‘ought’ and even more kinds of ‘can’. In this essay, I shall focus on a particular kind of ‘ought’ – specifically, on what I shall call the “rational ‘ought’”. On every occasion of use, this kind of ‘ought’ is focused on the situation of a particular agent at a particular time; but this kind of ‘ought’ is concerned, not with how that agent acts at (...) that time, but with what beliefs or intentions the agent has at the time, or with the sort of reasoning by means of which the agent at that time forms or revises those beliefs or intentions. (shrink)

E j lemmon, B a o williams, Bas van fraassen, And ruth marcus have argued on behalf of the existence of moral dilemmas, I.E., Cases where an agent is subject to conflicting absolute moral obligations. The paper criticizes this support and contends that no moral dilemma is possible.

Currently, the most popular views about how to update de se or self-locating beliefs entail the one-third solution to the Sleeping Beauty problem.2 Another widely held view is that an agent‘s credences should be countably additive.3 In what follows, I will argue that there is a deep tension between these two positions. For the assumptions that underlie the one-third solution to the Sleeping Beauty problem entail a more general principle, which I call the Generalized Thirder Principle, and there are situations (...) in which the latter principle and the principle of Countable Additivity cannot be jointly satisfied. The most plausible response to this tension, I argue, is to accept both of these principles, and to maintain that when an agent cannot satisfy them both, she is faced with a rational dilemma. (shrink)

This paper summarizes and systematizes recent and ongoing work on non-prioritized belief change, i.e., belief revision in which the new information has no special priority due to its novelty.

According to ‘ought’ implies ‘can’ (OIC), your obligation can never be to do what you cannot do. In a recent attack on OIC, Graham has argued that intuitions about justified intervention can help us determine whether the agent whose actions we use force to prevent would have acted permissibly or not. These intuitions, he suggests, cause trouble for the idea that you can be obligated to refrain from doing what you can refrain from doing. I offer a defense of OIC (...) and explain how non-consequentialists can accommodate his intuitions about his cases. (shrink)

A moral dilemma is a situation in which an agent ought to do each of two actions, Both of which he cannot do. If there are genuine moral dilemmas, The ethical theorist is presented with a problem: he must reject several very plausible principles of standard deontic logic. The main reasons usually given to show that there are moral dilemmas are examined, And it is argued that they are not sufficient. Several positive arguments are then presented, Arguments which try to (...) show that an adequate moral theory must rule out the possibility of genuine dilemmas. (shrink)

In this paper, I argue that the “Ought Implies Can” (OIC) principle, as it is employed in epistemology, particularly in the literature on epistemic norms, is open to counterexamples. I present a counterexample to OIC and discuss several objections to it. If this counterexample works, then it shows that it is possible that S ought to believe that p, even though S cannot believe that p. If this is correct, then OIC, considered from an epistemic point of view, is false, (...) since it is supposed to hold for any S and any p. (shrink)

I develop a non-representationalist account of mathematical thought, on which the point of mathematical theorizing is to provide us with the conceptual capacity to structure and articulate information about the physical world in an epistemically useful way. On my view, accepting a mathematical theory is not a matter of having a belief about some subject matter; it is rather a matter of structuring logical space, in a sense to be made precise. This provides an elegant account of the cognitive utility (...) of mathematics. Further, it makes explicit how the brand of non-representationalism I develop is compatible with there being substantive rationality constraints on our mathematical theorizing. (shrink)

§1. Introduction. I dedicate this essay to the two-dozen-odd people whose refutations of Cantor's diagonal argument have come to me either as referee or as editor in the last twenty years or so. Sadly these submissions were all quite unpublishable; I sent them back with what I hope were helpful comments. A few years ago it occurred to me to wonder why so many people devote so much energy to refuting this harmless little argument—what had it done to make them (...) angry with it? So I started to keep notes of these papers, in the hope that some pattern would emerge.These pages report the results. They might be useful for editors faced with similar problem papers, or even for the authors of the papers themselves. But the main message to reach me is that there are several points of basic elementary logic that we usually teach and explain very badly, or not at all.In 1995 an engineer named William Dilworth, who had published a refutation of Cantor's argument in the Transactions of the Wisconsin Academy of Sciences, Arts and Letters, sued for libel a mathematician named Underwood Dudley who had called him a crank. (shrink)

Epistemologists and philosophers of mind both ask questions about belief. Epistemologists ask normative questions about belief—which beliefs ought we to have? Philosophers of mind ask metaphysical questions about belief—what are beliefs, and what does it take to have them? While these issues might seem independent of one another, there is potential for an interesting sort of conflict: the epistemologist might think we ought to have beliefs that, according to the philosopher of mind, it is impossible to have. This essay argues (...) that this conflict does arise and that it creates problems for traditional skeptical views in epistemology. In particular, it argues that on certain popular views about the nature of belief, it is impossible to adopt the near-global agnosticism recommended by the skeptical epistemologist. On other plausible views, it is possible only in special circumstances, and this limitation undermines skeptical epistemological claims. The only views about the nature of belief on which there are no metaphysical hurdles to adopting the agnosticism recommended by the skeptic are views that face powerful objections—objections that are completely independent of antiskeptical epistemological considerations. (shrink)