I advocate Time-Slice Rationality, the thesis that the relationship between two time-slices of the same person is not importantly different, for purposes of rational evaluation, from the relationship between time-slices of distinct persons. The locus of rationality, so to speak, is the time-slice rather than the temporally extended agent. This claim is motivated by consideration of puzzle cases for personal identity over time and by a very moderate form of internalism about rationality. Time-Slice Rationality conflicts with two proposed principles of (...) rationality, Conditionalization and Reflection. Conditionalization is a diachronic norm saying how your current degrees of belief should fit with your old ones, while Reflection is a norm enjoining you to defer to the degrees of belief that you expect to have in the future. But they are independently problematic and should be replaced by improved, time-slice-centric principles. Conditionalization should be replaced by a synchronic norm saying what degrees of belief you ought to have given your current evidence and Reflection should be replaced by a norm which instructs you to defer to the degrees of belief of agents you take to be experts. These replacement principles do all the work that the old principles were supposed to do while avoiding their problems. In this way, Time-Slice Rationality puts the theory of rationality on firmer foundations and yields better norms than alternative, non-time-slice-centric approaches. (shrink)

A number of cases involving self-locating beliefs have been discussed in the Bayesian literature. I suggest that many of these cases, such as the sleeping beauty case, are entangled with issues that are independent of self-locating beliefs per se. In light of this, I propose a division of labor: we should address each of these issues separately before we try to provide a comprehensive account of belief updating. By way of example, I sketch some ways of extending Bayesianism in order (...) to accommodate these issues. Then, putting these other issues aside, I sketch some ways of extending Bayesianism in order to accommodate self-locating beliefs. Finally, I propose a constraint on updating rules, the "Learning Principle", which rules out certain kinds of troubling belief changes, and I use this principle to assess some of the available options. (shrink)

Bayesian probability is normally defined over a fixed language or eventspace. But in practice language is susceptible to change, and thequestion naturally arises as to how Bayesian degrees of belief shouldchange as language changes. I argue here that this question poses aserious challenge to Bayesianism. The Bayesian may be able to meet thischallenge however, and I outline a practical method for changing degreesof belief over changes in finite propositional languages.

How should one react when one has a belief, but knows that other people—who have roughly the same evidence as one has, and seem roughly as likely to react to it correctly—disagree? This paper argues that the disagreement of other competent inquirers often requires one to be much less confident in one’s opinions than one would otherwise be.

In this paper, I motivate a puzzle about epistemic rationality. On the one hand, there seems to be something problematic about frequently changing your mind. On the other hand, changing your mind once is often permissible. Why do one-off changes of mind seem rationally permissible, even admirable, while constant changes seem quintessentially irrational? The puzzle of fickleness is to explain this asymmetry. To solve the puzzle, I propose and defend the Ratifiable Reasoning Account. According to this solution, as agents redeliberate, (...) they gain two types of evidence. First, they gain inductive evidence that they will not stably settle their belief. Second, this inductive evidence affords higher-order evidence that they are unreliable at assessing the matter at hand. The fact that fickle agents gain this higher-order evidence explains why fickleness can be epistemically—not just practically—irrational. In addition to solving the puzzle, my account captures a wide range of contextual factors that are relevant for our judgments. (shrink)

David Christensen and others argue that Dutch Strategies are more like peer disagreements than Dutch Books, and should not count against agents‘ conformity to ideal rationality. I review these arguments, then show that Dutch Books, Dutch Strategies, and peer disagreements are only possible in the case of what computer scientists call Byzantine Failures—uncorrected Byzantine Faults which update arbitrary values. Yet such Byzantine Failures make agents equally vulnerable to all three kinds of epistemic inconsistencies, so there is no principled basis for (...) claiming that only avoidance of true Dutch Books characterizes ideally rational agents. Agents without Byzantine Failures can be ideally rational in a very strong sense, but are not normative for humans. (shrink)

One explanation of rational peer disagreement is that agents find themselves in an epistemically permissive situation. In fact, some authors have suggested that, while evidence could be impermissive at the intrapersonal level, it is permissive at the interpersonal level. In this paper, I challenge such a claim. I will argue that, at least in cases of rational disagreement under full disclosure, there cannot be more interpersonal epistemically permissive situations than there are intrapersonal epistemically permissive situations. In other words, with respect (...) to cases of disagreement under full disclosure, I will argue that there is a necessary connection between interpersonal permissiveness and its intrapersonal counterpart. Specifically, I claim that a plausible principle of correct argumentation supports such a bridge. (shrink)

In Willing, Wanting, Waiting, Richard Holton lays out a detailed account of resolutions, arguing that they enable agents to resist temptation. Holton claims that temptation often leads to inappropriate shifts in judgment, and that resolutions are a special kind of first- and second-order intention pair that blocks such judgment shift. In this paper, I elaborate upon an intuitive but underdeveloped objection to Holton’s view – namely, that his view does not enable agents to successfully block the transmission of temptation in (...) the way that he claims, because the second-order intention is as equally susceptible to temptation as the first-order intention alone would be. I appeal to independently compelling principles – principles that Holton should accept, because they help fill an important explanatory gap in his account – to demonstrate why this objection succeeds. This argument both shows us where Holton’s view goes wrong and points us to the kind of solu-tion we need. In conclusion, I sketch an alternative account of resolutions as a first-order intention paired with a second-order desire. I argue that my account is not susceptible to the same objection because a temptation that cannot be blocked by an intention can be blocked by a desire. (shrink)

Much of the plausibility of epistemic conservatism derives from its prospects of explaining our rationality in holding memory beliefs. In the first two parts of this paper, I argue for the inadequacy of the two standard approaches to the epistemology of memory beliefs, preservationism and evidentialism. In the third, I point out the advantages of the conservative approach and consider how well conservatism survives three of the strongest objections against it. Conservatism does survive, I claim, but only if qualified in (...) certain ways. Appropriately qualified, conservatism is no longer the powerful anti-skeptical tool some have hoped for, but a doctrine closely connected with memory. (shrink)

It’s been argued that there are no diachronic norms of epistemic rationality. These arguments come partly in response to certain kinds of counterexamples to Conditionalization, but are mainly motivated by a form of internalism that appears to be in tension with any sort of diachronic coherence requirements. I argue that there are, in fact, fundamentally diachronic norms of rationality. And this is to reject at least a strong version of internalism. But I suggest a replacement for Conditionalization that salvages internalist (...) intuitions, and carves a middle ground between conservatism and evidentialism. (shrink)

Epistemology should take seriously the possibility of rationally evaluable changes in conceptual resources. Epistemic decision theory compares belief states in terms of epistemic value. But it's standardly restricted to belief states that don't differ in their conceptual resources. I argue that epistemic decision theory should be generalized to make belief states with differing concepts comparable. I characterize some possible constraints on epistemic utility functions. Traditionally, the epistemic utility of a total belief state has been understood as a function of the (...) epistemic utility of individual (partial) beliefs. The most natural ways of generalizing this account generate a kind of repugnant conclusion. I characterize some possible alternatives, reflecting different epistemic norms. (shrink)

We defend Uniqueness, the claim that given a body of total evidence, there is a uniquely rational doxastic state that it is rational for one to be in. Epistemic rationality doesn't give you any leeway in forming your beliefs. To this end, we bring in two metaepistemological pictures about the roles played by rational evaluations. Rational evaluative terms serve to guide our practices of deference to the opinions of others, and also to help us formulate contingency plans about what to (...) believe in various situations. We argue that Uniqueness vindicates these two roles for rational evaluations, while Permissivism clashes with them. (shrink)

Some philosophers have recently argued that there are no diachronic norms of epistemic rationality, that is, that there are no norms regarding how you should change your attitudes over time. I argue that this is wrong on the grounds that there are norms governing reasoning.

What is the nature of rational disagreement? A number of philosophers have recently addressed this question by examining how we should respond to epistemic conflict with a so-called epistemic peer—that is, someone over whom you enjoy no epistemic advantage. Some say that you're rationally required to suspend judgment in these cases—thereby denying the very possibility of a certain kind of rational disagreement. Others say that it's permissible to retain your beliefs even in the face of epistemic conflict. By distinguishing between (...) close peers and distant peers, I argue that it's rational to respond to different types of peers in different ways. I also argue that remote peers—a particularly distant kind of distant peer—provide us with an important lesson in epistemic humility. (shrink)

Conditionalization is a norm that governs the rational reallocation of credence. I distinguish between factive and non-factive formulations of Conditionalization. Factive formulations assume that the conditioning proposition is true. Non-factive formulations allow that the conditioning proposition may be false. I argue that non-factive formulations provide a better foundation for philosophical and scientific applications of Bayesian decision theory. I furthermore argue that previous formulations of Conditionalization, factive and non-factive alike, have almost universally ignored, downplayed, or mishandled a crucial causal aspect of (...) Conditionalization. To formulate Conditionalization adequately, one must explicitly address the causal structure of the transition from old credences to new credences. I offer a formulation of Conditionalization that takes these considerations into account, and I compare my preferred formulation with some prominent formulations found in the literature. (shrink)

Credal Conservatism says that an agent’s credal states should be conserved as far as possible when she undergoes a learning experience. Uniqueness says that for any given total evidence, there is a unique credal state that any agent with that total evidence should have. Epistemic Impartiality is the idea that there are no significant differences between intrapersonal and interpersonal rationality requirements when determining what credal states one ought to have for purposes of epistemic evaluation. I construe Epistemic Impartiality as a (...) meta-principle governing epistemic norms, and argue that it is compatible with Conservatism. Then I show that on the assumption of Epistemic Impartiality, Credal Conservatism is equivalent to Uniqueness. (shrink)

Simon Evnine examines various epistemic aspects of what it is to be a person. Persons are defined as finite beings that have beliefs, including second-order beliefs about their own and others' beliefs, and are agents, capable of making long-term plans. It is argued that for any being meeting these conditions, a number of epistemic consequences obtain. First, all such beings must have certain logical concepts and be able to use them in certain ways. Secondly, there are at least two principles (...) governing belief that it is rational for persons to satisfy and are such that nothing can be a person at all unless it satisfies them to a large extent. These principles are that one believe the conjunction of one's beliefs and that one treat one's future beliefs as, by and large, better than one's current beliefs. Thirdly, persons both occupy epistemic points of view on the world and show up within those views. This makes it impossible for them to be completely objective about their own beliefs. Ideals of rationality that require such objectivity, while not necessarily wrong, are intrinsically problematic for persons. This "aspectual dualism" is characteristic of treatments of persons in the Kantian tradition. In sum, these epistemic consequences support a traditional view of the nature of persons, one in opposition to much recent theorizing. (shrink)

This paper looks at the question of what form the requirements of practical rationality take. One common view is that the requirements of rationality are wide-scope, and another is that they are narrow-scope. I argue that the resolution to the question of wide-scope versus narrow-scope depends to a significant degree on what one expects a theory of rationality to do. In examining these expectations, I consider whether there might be a way to unify requirements of both forms into a single (...) theory of rationality, and what the difficulties involved in doing so can teach us about the foundations of practical rationality. (shrink)

Recently, Levinstein has offered two interesting arguments concerning epistemic norms and epistemic peer disagreement. In his first argument, Levinstein claims that a tension between Permissivism and steadfast attitudes in the face of epistemic peer disagreement generally leads us to conciliatory attitudes; in his second argument, he argues that, given an ‘extremely weak version of a deference principle,’ Permissivism collapses into Uniqueness. However, in this paper, I show that when we clearly distinguish among several types of Permissivism, Permissivism\, and Permissivism\), we (...) can see that any type of Permissivism fits well with steadfast attitudes. Further, even though Levinstein’s ‘extremely weak version of a deference principle’ does rule out a possibility for some types of Permissivism and Permissivism\), it is still compatible with the other type of Permissivism ), so we may regard at least that version of a deference principle as a viable position in connection with that particular type of permissive rationality. (shrink)

Epistemic conservatism is the thesis that the mere holding of a belief confers some positive epistemic status on its content. Conservatism is widely criticized on the grounds that it conflicts with the main goal in epistemology to believe truths and disbelieve falsehoods. In this paper I argue for conservatism and defend it from objections. First, I argue that the objection to conservatism from the truth goal in epistemology fails. Second, I develop and defend an argument for conservatism from the perspectival (...) character of the truth goal. Finally, I examine several forceful challenges to conservatism and argue that these challenges are unsuccessful. The first challenge is that conservatism implies the propriety of assertions like ‘I believe p and this is part of my justification for it’. The second challenge argues that conservatism wrongly implies that the identity of an epistemic agent is relevant to the main goal of believing truths and disbelieving falsehoods. The last two challenges I consider are the ‘extra boost’ objection and the conversion objection. Each of these objections helps to clarify the nature of the conservative thesis. The upshot of the paper is that conservatism is an important and viable epistemological thesis. (shrink)