There are many things—call them ‘experts’—that you should defer to in forming your opinions. The trouble is, many experts are modest: they’re less than certain that they are worthy of deference. When this happens, the standard theories of deference break down: the most popular (“Reflection”-style) principles collapse to inconsistency, while their most popular (“New-Reflection”-style) variants allow you to defer to someone while regarding them as an anti-expert. We propose a middle way: deferring to someone involves preferring to make any decision (...) using their opinions instead of your own. In a slogan, deferring opinions is deferring decisions. Generalizing the proposal of Dorst (2020a), we first formulate a new principle that shows exactly how your opinions must relate to an expert’s for this to be so. We then build off the results of Levinstein (2019) and Campbell-Moore (2020) to show that this principle is also equivalent to the constraint that you must always expect the expert’s estimates to be more accurate than your own. Finally, we characterize the conditions an expert’s opinions must meet to be worthy of deference in this sense, showing how they sit naturally between the too-strong constraints of Reflection and the too-weak constraints of New Reflection. (shrink)

On at least one of its uses, ‘higher-order evidence’ refers to evidence about what opinions are rationalized by your evidence. This chapter surveys the foundational epistemological questions raised by such evidence, the methods that have proven useful for answering them, and the potential consequences and applications of such answers.

Is more information always better? Or are there some situations in which more information can make us worse off? Good (1967) argues that expected utility maximizers should always accept more information if the information is cost-free and relevant. But Good's argument presupposes that you are certain you will update by conditionalization. If we relax this assumption and allow agents to be uncertain about updating, these agents can be rationally required to reject free and relevant information. Since there are good reasons (...) to be uncertain about updating, rationality can require you to prefer ignorance. (shrink)

The guiding thread of the paper is the diagnosis that the advanced division of cognitive labor (that is, intellectual specialization) engenders a set of perennial, political and epistemic challenges (Millgram 2015) that, simultaneously, also generate opportunities for philosophy. In this paper, I re-characterize the nature of synthetic philosophy as a means to advance and institutionalize philosophy. For my definition of synthetic philosophy see section 2. In section 1, I treat Plato’s Republic as offering two models to represent philosophy's relationship to (...) the other sciences within the advanced division of labor. I highlight that for Plato intellectual specialization is central not just to economic, but also to political life. And, yet, that the very dispersion of scientific expertise, and its esoteric nature, also generates non-trivial challenges to the recognition and political utilization of knowledge. From Plato we can infer that in imperfect circumstances, philosophy’s self-constitution is, in part, a response to these challenges in political epistemology. However, how philosophy is institutionalized differs through time. In section 2, I re-introduce my conceptualization of synthetic philosophy and restate it. This makes visible that synthetic philosophy is already widely practiced in the profession as philosophy of the special sciences, PPE, formal modelling, public philosophy, etc. I use recent work by Dorst (2023) to illustrate synthetic philosophy and to identify some of the processes that give rise to the need for it. In sections 2-3, I contrast my account with the evolving ways that Philip Kitcher has conceptualized synthetic philosophy in order to make more precise the version promoted here. I do so not just because Kitcher and I use the same term, ‘synthetic philosophy,’ but because the temptations inherent in Kitcher’s approach should be resisted. -/- . (shrink)

This paper argues for several related theses. First, the epistemological position that knowledge requires safe belief can be motivated by views in the philosophy of science, according to which good explanations show that their explananda are robust. This motivation goes via the idea—recently defended on both conceptual and empirical grounds—that knowledge attributions play a crucial role in explaining successful action. Second, motivating the safety requirement in this way creates a choice point—depending on how we understand robustness, we'll end up with (...) different conceptions of safety in epistemology. Lastly, and most controversially, there's an attractive choice at this point that will not vindicate some of the most influential applications of the safety-theoretic framework in epistemology, e.g., Williamson's arguments against the KK principle, and luminosity. (shrink)

Philosophy and Phenomenological Research, EarlyView.

Epistemic iteration principles are principles according to which some or another epistemic operator automatically iterates---e.g., if it is known that P, then it is known that P, or there is evidence that P, then there is evidence that there is evidence that P. This article provides a survey of various arguments for and against epistemic iteration principles, with a focus on arguments relevant to a wide range of such principles.

The guiding thread of the paper is the diagnosis that the advanced division of cognitive labour (that is, intellectual specialization) engenders a set of perennial, political and epistemic challenges (Millgram 2015) that, simultaneously, also generate opportunities for philosophy. In this paper, I re-characterize the nature of synthetic philosophy as a means to advance and institutionalize philosophy. In §i, I treat Plato’s Republic as offering two models to represent philosophy’s relationship to the other sciences within the advanced division of labour. I (...) highlight that for Plato intellectual specialization is central not just to economic but also to political life; and yet, that the very dispersion of scientific expertise, and its esoteric nature, also generates non-trivial challenges to the recognition and political utilization of knowledge. From Plato we can infer that in imperfect circumstances, philosophy’s self-constitution is, in part, a response to these challenges in political epistemology. However, how philosophy is institutionalized differs through time. In §ii, I re-introduce my conceptualization of synthetic philosophy and restate it. I use recent work by Dorst (2023) to illustrate synthetic philosophy and to identify some of the processes that give rise to the need for it. In §§ii–iii, I contrast my account with the evolving ways that Philip Kitcher has conceptualized synthetic philosophy, in order to make more precise the version promoted here. I do so not just because Kitcher and I use the same term, ‘synthetic philosophy’, but because the temptations inherent in Kitcher’s approach should be resisted. (shrink)

Some arguments against the assumption that ordinary people may share common knowledge are sound. The apparent cost of such arguments is the rejection of scientific theories that appeal to common knowledge. My proposal is to accept the arguments without rejecting the theories. On my proposal, common knowledge is shared by ideally rational people, who are not just mathematically simple versions of ordinary people. They are qualitatively different from us, and theorizing about them does not lead to predictions about our behavior. (...) Nevertheless, models of action that assume common knowledge have a role to play in our understanding of collective rationality. (shrink)

The impossibility theorem of Dekel, Lipman and Rustichini has been thought to demonstrate that standard state-space models cannot be used to represent unawareness. We first show that Dekel, Lipman and Rustichini do not establish this claim. We then distinguish three notions of awareness, and argue that although one of them may not be adequately modeled using standard state spaces, there is no reason to think that standard state spaces cannot provide models of the other two notions. In fact, standard space (...) models of these forms of awareness are attractively simple. They allow us to prove completeness and decidability results with ease, to carry over standard techniques from decision theory, and to add propositional quantifiers straightforwardly. (shrink)

The epistemology of disagreement standardly divides conciliationist views from steadfast views. But both sorts of views are subject to counterexample—indeed, both sorts of views are subject to the same counterexample. After presenting this counterexample, I explore how the epistemology of disagreement should be reconceptualized in light of it.

This short paper has two parts. First,we prove a generalisation of Aumann’s surprising impossibility result in the context of rational decision making. We then move, in the second part, to discuss the interpretational meaning of some formal setups of epistemic models, and we do so by means of presenting an interesting puzzle in epistemic logic. The aim is to highlight certain problematic aspects of these epistemic systems concerning first/third-person asymmetry which underlies both parts of the story. This asymmetry, we argue, (...) reveals certain limits of what epistemic models can be. (shrink)

The early literature on epistemic logic in philosophy focused on reasoning about the knowledge or belief of a single agent, especially on controversies about "introspection axioms" such as the 4 and 5 axioms. By contrast, the later literature on epistemic logic in computer science and game theory has focused on multi-agent epistemic reasoning, with the single-agent 4 and 5 axioms largely taken for granted. In the relevant multi-agent scenarios, it is often important to reason about what agent A believes about (...) what agent B believes about what agent A believes; but it is rarely important to reason just about what agent A believes about what agent A believes. This raises the question of the extent to which single-agent introspection axioms actually matter for multi-agent epistemic reasoning. In this paper, we formalize and answer this question. To formalize the question, we first define a set of multi-agent formulas that we call agent-alternating formulas, including formulas like Box_a Box_b Box_a p but not formulas like Box_a Box_a p. We then prove, for the case of belief, that if one starts with multi-agent K or KD, then adding both the 4 and 5 axioms (or adding the B axiom) does not allow the derivation of any new agent-alternating formulas—in this sense, introspection axioms do not matter. By contrast, we show that such conservativity results fail for knowledge and multi-agent KT, though they hold with respect to a smaller class of agent-nonrepeating formulas. (shrink)

My dissertation is about Bayesian rationality for non-ideal agents. I show how to derive subjective probabilities from preferences using much weaker rationality assumptions than other standard representation theorems. I argue that non-ideal agents might be uncertain about how they will update on new information and consider two consequences of this uncertainty: such agents should sometimes reject free information and make choices which, taken together, yield sure loss. The upshot is that Bayesian rationality for non-ideal agents makes very different normative demands (...) than ideal Bayesian rationality. (shrink)

Aumann’s theorem states that no individual should agree to disagree under a range of assumptions. Political liberalism appears to presuppose these assumptions with the idealized conditions of public reason. We argue Aumann’s theorem demonstrates they nevertheless cannot be simultaneously held with what is arguably political liberalism’s most central tenet. That is, the tenet of reasonable pluralism, which implies we can rationally agree to disagree over conceptions of the good. We finish by elaborating a way of relaxing one of the theorem’s (...) axioms that arguably lends itself to a coherent account of political liberalism, namely the condition of indexical independence. (shrink)

In conversation, speakers often felicitously underspecify the content of their speech acts, leaving audiences uncertain about what they mean. This paper discusses how such underspecification and the resulting uncertainty can be used deliberately, and manipulatively, to achieve a range of noncommunicative conversational goals—including minimizing conversational conflict, manufacturing acceptance or perceived agreement, and gaining or bolstering status. I argue that speakers who manipulatively underspecify their speech acts in this way are engaged in a mock speech act that I call _pied piping_. (...) In pied piping, a speaker leaves open a range of interpretations for a speech act while preserving both plausible deniability and plausible assertability; depending on how the audience responds, the speaker can retroactively commit to any of the interpretations left open, and so try to retroactively update the common ground. I go on to develop a model of how pied-piping functions that incorporates game-theoretic elements into the more traditional common-ground framework in order to capture the uncertainty of updating. (shrink)

In conversation, speakers often felicitously underspecify the content of their speech acts, leaving audiences uncertain about what they mean. This paper discusses how such underspecification and the resulting uncertainty can be used deliberately, and manipulatively, to achieve a range of noncommunicative conversational goals—including minimizing conversational conflict, manufacturing acceptance or perceived agreement, and gaining or bolstering status. I argue that speakers who manipulatively underspecify their speech acts in this way are engaged in a mock speech act that I call _pied piping_. (...) In pied piping, a speaker leaves open a range of interpretations for a speech act while preserving both plausible deniability and plausible assertability; depending on how the audience responds, the speaker can retroactively commit to any of the interpretations left open, and so try to retroactively update the common ground. I go on to develop a model of how pied-piping functions that incorporates game-theoretic elements into the more traditional common-ground framework in order to capture the uncertainty of updating. (shrink)

In conversation, speakers often felicitously underspecify the content of their speech acts, leaving audiences uncertain about what they mean. This paper discusses how such underspecification and the resulting uncertainty can be used deliberately, and manipulatively, to achieve a range of noncommunicative conversational goals—including minimizing conversational conflict, manufacturing acceptance or perceived agreement, and gaining or bolstering status. I argue that speakers who manipulatively underspecify their speech acts in this way are engaged in a mock speech act that I call _pied piping_. (...) In pied piping, a speaker leaves open a range of interpretations for a speech act while preserving both plausible deniability and plausible assertability; depending on how the audience responds, the speaker can retroactively commit to any of the interpretations left open, and so try to retroactively update the common ground. I go on to develop a model of how pied-piping functions that incorporates game-theoretic elements into the more traditional common-ground framework in order to capture the uncertainty of updating. (shrink)

In conversation, speakers often felicitously underspecify the content of their speech acts, leaving audiences uncertain about what they mean. This paper discusses how such underspecification and the resulting uncertainty can be used deliberately, and manipulatively, to achieve a range of noncommunicative conversational goals—including minimizing conversational conflict, manufacturing acceptance or perceived agreement, and gaining or bolstering status. I argue that speakers who manipulatively underspecify their speech acts in this way are engaged in a mock speech act that I call _pied piping_. (...) In pied piping, a speaker leaves open a range of interpretations for a speech act while preserving both plausible deniability and plausible assertability; depending on how the audience responds, the speaker can retroactively commit to any of the interpretations left open, and so try to retroactively update the common ground. I go on to develop a model of how pied-piping functions that incorporates game-theoretic elements into the more traditional common-ground framework in order to capture the uncertainty of updating. (shrink)