Since at least as long ago as Plato’s time, philosophers have considered the possibility that justice is at bottom a system of rules that members of society follow for mutual advantage. Some maintain that justice as mutual advantage is a fatally flawed theory of justice because it is too exclusive. Proponents of a Vulnerability Objection argue that justice as mutual advantage would deny the most vulnerable members of society any of the protections and other benefits of justice. I argue that (...) the Vulnerability Objection presupposes that in a justice-as-mutual-advantage society only those who can and do contribute to the cooperative surplus of benefits that compliance with justice creates are owed any share of these benefits. I argue that justice as mutual advantage need not include such a Contribution Requirement. I show by example that a justice-as-mutual-advantage society can extend the benefits of justice to all its members, including the vulnerable who cannot contribute. I close by arguing that if one does not presuppose a Contribution Requirement, then a justice-as-mutual-advantage society might require its members to extend the benefits of justice to humans that some maintain are not persons (for example, embryos) and to certain nonhuman creatures. I conclude that the real problem for defenders of justice as mutual advantage is that this theory of justice threatens to be too inclusive. (shrink)

One does not simply predict where the other will go, which is wherever the first predicts the second to predict the first to go, and so ad infinitum. Not "What would I do if I were she?" but "What would I do if I were she wondering what she would do if she were wondering what I would do if I were she...?".

I propose a dynamical analysis of interaction in anarchy, and argue that this kind of dynamical analysis is a more promising route to predicting the outcome of anarchy than the more traditional a priori analyses of anarchy in the literature. I criticize previous a priori analyses of anarchy on the grounds that these analyses assume that the individuals in anarchy share a unique set of preferences over the possible outcomes of war, peace, exploiting others and suffering exploitation. Following Hobbes' classic (...) analysis of anarchy, I maintain that typically in anarchy some moderate individuals will most desire mutual cooperation while other dominators will most desire to exploit others' cooperation. I argue that once one allows for different types of individuals in anarchy, any a priori analysis of anarchy requires unrealistic assumptions regarding the agents' common knowledge of their situation. However, this move also suggests a dynamical analysis of anarchy, one that assumes no common knowledge. In the Variable Anticipation threshold model developed here, individuals modify their behavior as they learn from repeated interactions. I present specific instances of this model where the individuals in anarchy converge to different equilibria corresponding to either peace or war, depending on the initial conditions. I show that individuals are liable to converge to Hobbes' war of all against all even if only a small percentage of are dominators. The presence of only a few “nasty” individuals gradually drives all, including those inclined to be “nicer”, to imitate the “nasty” conduct of these few. This dynamic analysis suggests that the Hobbesian war in anarchy is indeed inevitable in most realistic circumstances. You have the same propension, that I have, in favor of what is contiguous above what is remote. You are, therefore, naturally carry'd to commit acts of injustice as well as I. Your example both pushes me forward in this way by imitation, and also affords me a new reason for any breach of equity, by showing me, that I shou'd be the cully of my integrity, if I alone shou'd impose on myself a severe restraint amidst the licentiousness of others. (David Hume, A Treatise of Human Nature) (Published Online July 11 2006) Footnotes1 Thanks to Luc Bovens, Sharon Lloyd, Brian Skyrms, Susanne Sreedhar and an anonymous referee for many helpful comments of early versions of this essay. (shrink)

Hume is rightly credited with giving a brilliant, and perhaps the best, account of justice as convention. Hume's importance as a forerunner of modern economics has also long been recognized. However, most of Hume's readers have not fully appreciated how closely Hume's analysis of convention foreshadows a particular branch of economic theory, namely, game theory. Starting with the work of Barry, Runciman and Sen and Lewis, there has been a flowering of literature on the informal game-theoretic insights to be found (...) in classics of political philosophy such as Hobbes, Locke, Hume and Rousseau. A number of authors in this tradition, including Lewis, Gauthier, Mackie, and Postema, have identified passages in Hume which they interpret as giving informal examples of specific games. Yet, unlike his predecessors, Hobbes and Locke, Hume does much more than present examples which have a game-theoretic structure. In his account of convention, Hume gives general conditions which characterize the resolution of social interaction problems, and in the examples he uses to illustrate this account, Hume outlines several different methods by which agents can arrive at such a resolution. Hume's general account of convention and his explanations of the origins of particular conventions together constitute a theory of strategic interaction, which is precisely what game theory aspires to be. (shrink)

The author defends the ancient claim that justice is at bottom a body of social conventions. Recent analytical and empirical concepts and results from the social sciences together with insights and arguments of past masters of moral and political philosophy are integrated into a new game-theoretic conventionalist analysis of justice.

Aconvention is a state in which agents coordinate their activity, not as the result of an explicit agreement, but because their expectations are aligned so that each individual believes that all will act so as to achieve coordination for mutual benefit. Since agents are said to follow a convention if they coordinate without explicit agreement, the notion raises fundamental questions: (1) Why do certain conventions remain stable over time?, and (2) How does a convention emerge in the first place? In (...) a pioneering study, Lewis (1969) addresses these questions by applyingnoncooperative game theory. Lewis defines a convention as aNash coordination equilibrium of a noncooperative game that issalient, that is, it is somehow conspicuous to the agents so that all expect one another to conform with the equilibrium. This paper presents a new game theoretic definition of conventions, which formalizes the notion of salience and which also generalizes the class of conventions Lewis discusses in his work. I define a convention as acorrelated equilibrium (Aumann 1974, 1987) satisfying apublic intentions criterion: Every agent wants his intended action to becommon knowledge. I argue that many conventions correspond to correlated equilibria that are not Nash equilibria, and that this is consistent with Lewis' general viewpoint. Finally, I argue that game theoretic characterizations of convention, such as Lewis' and my own, help to explain a convention's stability, but that a fully satisfactory account of the emergence of convention requires a theory of equilibrium selection beyond the scope of Lewis' work. (shrink)

Vanderschraaf develops a new theory of game theory equilibrium selection in this book. The new theory defends general correlated equilibrium concepts and suggests a new analysis of convention.

Peter Vanderschraaf. Game Theory, Evolution and Justice.

In their classic analyses, Hobbes and Hume argue that offensively violating a covenant is irrational because the offense ruins one’s reputation. This paper explores conditions under which reputation alone can enforce covenants. The members of a community are modeled as interacting in a Covenant Game repeated over time. Folk theorems are presented that give conditions under which the Humean strategy of performing in covenants only with those who have never offensively violated or performed with an offensive violator characterizes an equilibrium (...) of the repeated Covenant Game. These folk theorems establish that for certain ideal settings Hobbes’ and Hume’s arguments against offensively violating covenants are compelling. However, these ideal settings presuppose that the community has certain mechanisms that generate common knowledge of the identities of those with whom one should perform. I analyze the results of computer simulations of the interactions in a community whose members must rely upon private communication alone. The computer simulation data show that in this community, reputation effects cannot effectively deter members from offensively violating covenants. I conclude that Hobbes’ and Hume’s warnings against offensive violation are compelling only on condition that the community is sufficiently structured to generate common knowledge among its members. I also conclude that even in such structured communities, the Humean strategy is not the uniquely “correct” policy. (shrink)

I reply to commentaries by Justin Bruner, Robert Sugden and Gerald Gaus. My response to Bruner focuses on conventions of bargaining problems and arguments for characterizing the just conventions of these problems as monotone path solutions. My response to Sugden focuses on how the laws of humanity present in Hume’s discussion of vulnerable individuals might be incorporated into my own proposed account of justice as mutual advantage. My response to Gaus focuses on whether or not my account of justice as (...) mutual advantage can incorporate deep differences in values across subgroups of a larger society. (shrink)

We introduce a dynamic model for evolutionary games played on a network where strategy changes are correlated according to degree of influence between players. Unlike the notion of stochastic stability, which assumes mutations are stochastically independent and identically distributed, our framework allows for the possibility that agents correlate their strategies with the strategies of those they trust, or those who have influence over them. We show that the dynamical properties of evolutionary games, where such influence neighborhoods appear, differ dramatically from (...) those where all mutations are stochastically independent, and establish some elementary convergence results relevant for the evolution of social institutions. (shrink)

I explore the evolution of strategies in an Augmented Stag Hunt game that adds a punishing strategy to the ordinary Stag Hunt strategies of cooperating, which aims for optimality, and defecting, which “plays it safe.” Cooperating weakly dominates punishing and defecting is the unique evolutionarily stable strategy. Nevertheless, for a wide class of Augmented Stag Hunts, polymorphic strategies combining punishing and cooperating collectively have greater attracting power for replicator dynamics than that of the ESS. The analysis here lends theoretical support (...) to the altruistic punishment hypothesis in the social sciences. (shrink)

In this article, I analyze the circumstances of justice, that is, the background conditions that are necessary and sufficient for justice to exist between individual parties in society. Contemporary political philosophers almost unanimously accept an account of these circumstances attributed to David Hume. I argue that the conditions of this standard account are neither sufficient nor necessary conditions for justice. In particular, I contend that both a Hobbesian state of nature and a prisoner’s dilemma are cases in which the conditions (...) of the standard account obtain and yet no justice exists between parties. I propose an alternative set of generic circumstances of justice motivated by examples from game theory. Parties are in these generic circumstances with respect to each other when: (1) they are engaged in a conflictual coordination game with multiple strict Nash equilibrium points where, at any of these equilibria, some parties do not receive their greatest payoffs, and (2) they have common knowledge that each party is rational and follows her end of a strict equilibrium where no party receives her greatest payoff. These two conditions reflect the idea that justice requires all parties to make some sacrifices so that others can have more of the goods they need and want. I argue that these generic circumstances are necessary and sufficient conditions for parties to follow generic norms of justice, that is, mutually beneficial practices that require some sacrifices. Key Words: common knowledge • conflictual coordination • correlated equilibrium • moderate selfishness • moderate variable scarcity • rough equality. (shrink)

I review the classic skeptical challenges of Foole in Leviathan and the Lydian Shepherd in Republic against the prudential rationality of justice. Attempts to meet these challenges contribute to the reconciliation project (Kavka in Hobbesian moral and political theory , 1986 ) that tries to establish that morality is compatible with rational prudence. I present a new Invisible Foole challenge against the prudential rationality of justice. Like the Lydian Shepherd, the Invisible Foole can violate justice offensively (Kavka, Hobbesian moral and (...) political theory , 1986 ; Law and Philosophy , 14:5–34, 1995 ) without harming his reputation for justice. And like the Foole, the Invisible Foole dismisses the possibility that being just preserves goods intrinsic to justice, and will be just only if he fears that others will punish his injustice by withholding the external goods like labor and material goods that he would otherwise receive for their performance in covenants. I argue that given a plausible folk-theorem interpretation , Hobbes’ response to the Foole’s challenge is inconclusive, and depends crucially upon common knowledge assumptions that may or may not obtain in actual societies. I present two analogous folk-theorem arguments in response to the Invisible Foole’s challenge, one using the idea that the Invisible Foole’s power of concealment might be transitory, and the other using the idea that members of society might stop performing in covenants with anyone, thus punishing the Invisible Foole indirectly, if the Invisible Foole commits sufficiently many injustices. (shrink)

In recent years, a number of authors have used gametheoretic reasoning to explain why purely self-interested agentswould ever conform their economic activities with the requirements of justice, when by doing so they forego opportunities to reapunilateral net gains by exploiting others. In this paper, I argue that Hume's justification of honest economic exchanges between self-interested agents in the Treatise foreshadows this contemporary literature. Hume analyzes the problem of explaining justice in self-interested economic exchange as a problem of agents coordinating on (...) a pattern of reciprocal cooperation, as opposed to some other behavioral pattern such as reciprocal exploitation, in exchanges repeated over time. Hume's arguments anticipate informally thecontemporary interpretation of just economic practices as forming part of an equilibrium of a repeated game. I close the paper by arguing that Hume does not provide a satisfactory explanation of how the mutual expectations that support justice in economic exchange arise in a community of self-interested agents. The problem Hume leaves unsolved is one of equilibrium selection, that is: Why do agents follow an equilibrium corresponding to just economic exchanges rather than some other equilibrium corresponding to unjust exchanges? I also argue that contemporary game theory still lacks a satisfactory theory of equilibrium selection, but that such a theory would lead us closer to a satisfactory Humean reconciliation of justice and self-interest in economic exchange. (shrink)

I resolve a previously unnoticed anomaly in the analysis of collective action problems. Some political theorists apply game theory to analyze the paradox of anarchy: War is apparently inevitable in anarchy even though all warring parties prefer peace over war. Others apply tipping threshold analysis to resolve the paradox of revolution: Joining a revolution is apparently always irrational even when an overwhelming majority of the population wish to replace their regime. The usual game theoretic analysis of anarchy yields the conclusion (...) that the suboptimal equilibrium of war is inevitable. The usual tipping threshold analysis of revolution yields the conclusion that the optimal equilibrium of successful revolution is possible. Yet structurally the collective action problems of anarchy and potential revolution are much the same. This suggests that tipping threshold analysis and game theory are incompatible methodologies, despite their widespread use in the social sciences. I argue that there is no real tension between game theory and tipping threshold analysis, even though these methodologies have developed largely independently of each other. I propose a Variable Belief Threshold model of collective action that combines elements of game theory and tipping threshold analysis. I show by example that one can use this kind of hybrid model to give compatible explanations of conflict in anarchy and successful revolution.1. Introduction2. Two Classic Problems, and Two Popular Analyses2.1. The paradox of anarchy2.2. The paradox of revolution3. Restating the Puzzle4. Evaluating the Prisoners’ Dilemma and S-Curve Models5. The Variable Belief Threshold ModelExample 5.1. A population of moderates with independent deviationsExample 5.2 A heterogeneous population with independent deviationsExample 5.3 A heterogeneous population with coordinated deviations6. ConclusionAppendix: Computer Simulations. (shrink)

Peter Vanderschraaf. Reputational Enforcement of Covenants.

Learning to take turns in repeated game situations is a robust phenomenon in both laboratory experiments and in everyday life. Nevertheless, it has received little attention in recent studies of learning dynamics in games. We investigate the simplest and most obvious extension of fictitious play to a learning rule that can recognize patterns, and show how players using this rule can spontaneously learn to take turns.

In this dissertation, I develop a theory of rational inductive deliberation in the context of strategic interaction that generalizes previous theories of inductive deliberation. In this account of inductive deliberation, I model rational deliberators as players engaged in noncooperative games, such that: They are Bayesian rational, in the sense that every deliberator chooses actions that maximize expected utility given the beliefs this deliberator has regarding the other deliberators, and They update their beliefs about one another recursively, using rules of inductive (...) logic. Inductive deliberators update their beliefs until they reach an equilibrium of the game, at which every deliberator maximizes expected utility given the deliberator's beliefs over the actions of the other deliberators. ;The theory of inductive deliberation generalizes previous theories by allowing for the possibility of correlation in the beliefs of the deliberators. Most of the results of noncooperative game theory presuppose that the players strategies are probabilistically independent. I argue that such probabilistic independence assumptions are unfounded, and that agents should take into account the possibility that their opponents' actions are correlated. Relaxing the probabilistic independence assumption in noncooperative game theory leads to various correlated equilibrium concepts, which I argue are the appropriate solution concepts for noncooperative games. Relaxing the independence assumption in the inductive dynamics enables correlation in the deliberators' beliefs to emerge spontaneously, resulting in the deliberators converging to correlated equilibrium. ;I devote the majority of the dissertation to the formal theory of inductive deliberation and correlated equilibrium. In particular, I show the following: Under suitable conditions, correlated equilibria correspond to fixed points of the dynamics, and The dynamics can create correlation in beliefs from an initial uncorrelated state. In the final chapter of the dissertation, I give an account of the origins of social conventions such as the use of particular words in human languages as the result of inductive deliberation. (shrink)

In recent years, a number of authors have used gametheoretic reasoning to explain why purely self-interested agentswould ever conform their economic activities with the requirements of justice, when by doing so they forego opportunities to reapunilateral net gains by exploiting others. In this paper, I argue that Hume's justification of honest economic exchanges between self-interested agents in the Treatise foreshadows this contemporary literature. Hume analyzes the problem of explaining justice in self-interested economic exchange as a problem of agents coordinating on (...) a pattern of reciprocal cooperation, as opposed to some other behavioral pattern such as reciprocal exploitation, in exchanges repeated over time. Hume's arguments anticipate informally thecontemporary interpretation of just economic practices as forming part of an equilibrium of a repeated game. I close the paper by arguing that Hume does not provide a satisfactory explanation of how the mutual expectations that support justice in economic exchange arise in a community of self-interested agents. The problem Hume leaves unsolved is one of equilibrium selection, that is: Why do agents follow an equilibrium corresponding to just economic exchanges rather than some other equilibrium corresponding to unjust exchanges? I also argue that contemporary game theory still lacks a satisfactory theory of equilibrium selection, but that such a theory would lead us closer to a satisfactory Humean reconciliation of justice and self-interest in economic exchange. (shrink)

The traditional solution concept for noncooperative game theory is the Nash equilibrium, which contains an implicit assumption that players’ probability distributions satisfy t probabilistic independence. However, in games with more than two players, relaxing this assumption results in a more general equilibrium concept based on joint beliefs. This article explores the implications of this joint-beliefs equilibrium concept for two kinds of conflictual coordination games: crisis bargaining and public goods provision. We find that, using updating consistent with Bayes’ rule, players’ beliefs (...) converge to equilibria in joint beliefs which do not satisfy probabilistic independence. In addition, joint beliefs greatly expand the set of mixed equilibria. On the face of it, allowing for joint beliefs might be expected to increase the prospects for coordination. However, we show that if players use joint beliefs, which may be more likely as the number of players increases, then the prospects for coordination in these games declines vis-à-vis independent beliefs. (shrink)

We introduce a dynamic model for evolutionary games played on a network where strategy changes are correlated according to degree of influence between players. Unlike the notion of stochastic stability, which assumes mutations are stochastically independent and identically distributed, our framework allows for the possibility that agents correlate their strategies with the strategies of those they trust, or those who have influence over them. We show that the dynamical properties of evolutionary games, where such influence neighborhoods appear, differ dramatically from (...) those where all mutations are stochastically independent, and establish some elementary convergence results relevant for the evolution of social institutions. (shrink)

Peter Vanderschraaf’s Strategic Justice is a powerful elaboration and defense of what he calls ‘justice as mutual advantage’. Vanderschraaf opens Strategic Justice by observing that ‘Plato set a template for all future philosophers by raising two interrelated questions: (1) What precisely is justice? (2) Why should one be just?’. He answers that (1) justice consists of conventions which (2) are followed because each sees that doing so is in her interest. These answers depend upon two conditions which (...) Vanderschraaf calls Baseline Consistency and Negative Mutual Expectations. I contend that the plausibility of the first condition depends upon principles which are prior to Vanderchraaf’s conventions of justice and that the second condition does not account for the interest Vanderschraaf must think we take in those principles. I therefore worry that Vanderschraaf does what he accuses other theorists of justice as mutual advantage of doing: going outside the bounds of justice as mutual advantage. To lay the groundwork for his conditions, Vanderschraaf analyzes the circumstances of justice. I argue that, his claims to the contrary notwithstanding, he does not take the circumstances to be the kind of conditions Hume takes them to be, but that he has good reason to do so. (shrink)

For more than twenty years, Peter Vanderschraaf’s work has combined rigorous game-theoretic analysis, innovative use of (social) scientific method, and normative analysis in the context of the social contract. Vanderschraaf’s work has influenced a significant interdisciplinary field of study and culminated in the publication of his book, Strategic Justice: Convention and Problems of Balancing Divergent Interests (OUP, 2019). Building upon his previous work, Vanderschraaf developed a new theory of justice (justice-as-convention) that, despite a mutual advantage approach, (...) considers the most vulnerable members of society and defends the egalitarian bargaining solution. To advance his theory, Vanderschraaf proposes an account of conventions that updates and systematizes David Lewis’s account of conventions, drawing on contemporary developments in game theory and economics. This topical collection brings together game theorists, philosophers, economists, and political scientists to discuss themes from Vanderschraaf’s work. The collection bridges a gap among disjoint but closely related literatures in game theory, bargaining theory, formal philosophy, rationality, equality, justice, and the social contract in order to advance dialogue among scholars in this rich and growing field of study. (shrink)

The most recent major contribution to the literature on justice as mutual advantage is Peter Vanderschraaf’s book Strategic Justice. In this book, he develops a theory of justice as convention, where justice is those principles that rational, self-interested agents would choose to solve problems of partially conflicting interest. His theory is thus a kind of theory of justice as mutual advantage. A common criticism of theories of justice as mutual advantage is the Vulnerability Objection: if the principles of (...) justice require that resources are only shared with those that are net-contributors to a cooperative surplus, then those that are not net-contributors to that cooperative surplus (so-called vulnerable people) have no claim of justice to any share of the resources. But, the objection states, surely justice cannot exclude people simply because they are vulnerable. Vanderschraaf argues that his theory of justice as convention successfully answers the Vulnerability Objection. However, in this paper, I argue that although Vanderschraaf’s theory successfully demonstrates that it can be to the mutual advantage of rational, self-interested people to agree to share equally even when some people contribute more than others, the problem remains of why such people would share with those that can never contribute more to the cooperative surplus than what they would withdraw from it. Vanderschraaf’s solution is to weaken the requirement that people actually contribute. But that, I argue, undermines the claim that his theory is a theory of justice as mutual advantage. (shrink)

The history of contractarian moral theory is long and varied. It includes the classic social contract theories of Hobbes (1651), Hume (1739/1740), and Kant (1785) as well as modern versions of these theories, such as those of Gauthier (1986), Scanlon (1998), Darwall (2006), and Southwood (2010). In Minimal Morality: A Multilevel Social Contract Theory (2018), I continue this tradition by developing a ‘multilevel social contract theory’ that combines Humean, Hobbesian, and Kantian moral features. In this article, I reply to comments (...) by Fred D’Agostino, John Thrasher, Christopher W. Morris, and Peter Vanderschraaf. I am deeply grateful for these commentators’ constructive and engaging comments that, in their own way, shed light on core assumptions and features of the theory. Due to space restrictions, I focus on what I consider to be the main criticisms and have organized my responses thematically. I hope that doing so will also help readers who are less familiar with my work to understand the relevance of multilevel social contract theory for morally diverse societies. (shrink)

As I write this, in November 1971, people are dying in East Bengal from lack of food, shelter, and medical caxc. The suffering and death that are occurring there now axe not inevitable, 1101; unavoidable in any fatalistic sense of the term. Constant poverty, a cyclone, and a civil war have turned at least nine million people into destitute refugees; nevertheless, it is not beyond Lhe capacity of the richer nations to give enough assistance to reduce any further suffering to (...) very small proportions. The decisions arid actions of human beings can prevent this kind of suffering. Unfortunately, human beings have not made the necessary decisions. At the individual level, people have, with very few exceptions, not responded to the situation in any signihczmt way. Generally speaking, people have not given large sums to relief funds; they have not written t0 their parliamentaxy representatives demanding increased government assistance; they have not demonstrated in the streets, held symbolic fasts, or done anything else directed toward providing thc refugees with the means to satisfy their essential needs. At thc government level, no govcrmmcnt has given the sort of massive aid that would enable the refugees to survive fm: more than a few days. Britain, for instance, has given rather more than most countries. It has, to date, given £14,750,000. For comparative purposes, B1~itain’s share of thc nonreccverabla development costs of the Anglo-French Concorde project is already in excess of £275,000,000, and on present estimates will reach £440,000,¤00. The implication is that the British government values a supersonic transport more than thirty times as.. (shrink)

There are two general classes of social conventions: conventions of coordination, and conventions of partial conflict. In coordination problems, the interests of the agents coincide, while in partial conflict problems, some agents stand to gain only if other agents unilaterally make certain sacrifices. Lewis' (1969) pathbreaking analysis of convention in terms of game theory focuses on coordination problems, and cannot accommodate partial conflict problems. In this paper, I propose a new game-theoretic definition of convention which generalizes previous game-theoretic definitions (Lewis (...) 1969, Vanderschraaf 1995), and which can be used to characterize norms of justice in partial conflict situations. I argue that the key structural property necessary for a social arrangement to be a convention is that it be conditionally self-enforcing, in the sense that: (i) each agent has a decisive reason to follow her end of the arrangement given that she expects all to do likewise, (ii) given a different set of expectations, some agents would have had a decisive reason to deviate, and (iii) these facts are common knowledge. This leads to a definition of convention as a strict correlated equilibrium (Aumann 1974) together with appropriate common knowledge conditions. Examples are given in which it is shown how this more general account of convention can be used to analyze norms of justice as well as coordination problems. It is only a general sense of common interest; which sense all the members of the society express to one another, and which induces them to regulate their conduct by certain rules. I observe, that it will be for my interest to leave another in the possession of his goods, provided he will act in the same manner with regard to me. He is sensible of a like interest in the regulation of his conduct. When this common sense of interest is mutually express'd, and is known to both, it produces a suitable resolution and behavior. And this may properly be call'd a convention or agreement betwixt us,.. (shrink)

This paper argues that a set of questioning attitudes are among the foundations of human and animal minds. While both verbal questioning and states of curiosity are generally explained in terms of metacognitive desires for knowledge or true belief, I argue that each is better explained by a prelinguistic sui generis type of mental attitude of questioning. I review a range of considerations in support of such a proposal and improve on previous characterizations of the nature of these attitudes. I (...) then broaden their explanatory scope to include a number of forms of exploratory search. The paper has three main goals: to characterize the nature of the questioning attitudes, outlining their causal role and type of content; to argue that they are fundamental components of the mind, being widespread among animals and not constructed during ontogeny out of other attitudes; and to suggest that they explain a great deal more behavior than one might think. (shrink)

Since its original publication in 1975, this groundbreaking work has awakened millions of people to the existence of "speciesism"—our systematic disregard of nonhuman animals—inspiring a worldwide movement to transform our attitudes to animals and eliminate the cruelty we inflict on them. In Animal Liberation, author Peter Singer exposes the chilling realities of today’s "factory farms" and product-testing procedures—destroying the spurious justifications behind them, and offering alternatives to what has become a profound environmental and social as well as moral issue. (...) An important and persuasive appeal to conscience, fairness, decency, and justice, it is essential reading for the supporter and the skeptic alike. (shrink)

We propose a solution to the problem of logical omniscience in what we take to be its fundamental version: as concerning arbitrary agents and the knowledge attitude per se. Our logic of knowledge is a spin-off from a general theory of thick content, whereby the content of a sentence has two components: an intension, taking care of truth conditions; and a topic, taking care of subject matter. We present a list of plausible logical validities and invalidities for the logic of (...) knowledge per se for arbitrary agents, and isolate three explanatory factors for them: the topic-sensitivity of content; the fragmentation of knowledge states; the defeasibility of knowledge acquisition. We then present a novel dynamic epistemic logic that yields precisely the desired validities and invalidities, for which we provide expressivity and completeness results. We contrast this with related systems and address possible objections. (shrink)

Single-premise epistemic closure is the principle that: if one is in an evidential position to know that P where P entails Q, then one is in an evidential position to know that Q. In this paper, I defend the viability of opposition to closure. A key task for such an opponent is to precisely formulate a restricted closure principle that remains true to the motivations for abandoning unrestricted closure but does not endorse particularly egregious instances of closure violation. I focus (...) on two brands of epistemic theory that naturally incorporate closure restrictions. The first type holds that the truth value of a knowledge ascription is relative to a relevant question. The second holds that the truth value of a knowledge ascription is relative to a relevant topic. For each approach, I offer a formalization of a leading theory from the literature and use this formalization to evaluate the theory’s adequacy in terms of a precise set of desiderata. I conclude that neither theory succeeds in meeting these desiderata, casting doubt on the viability of the underlying approaches. Finally, I offer a novel variant of the topic-sensitive approach that fares better. (shrink)

Introduction These essays have been written over a period of about ten years and have already been published separately in various places. ...

I lay out the framework for my theory of sensory imagination in “Imagining as a guide to possibility.” Sensory imagining involves mental imagery , and crucially, in describing the content of imagining, I distinguish between qualitative content and assigned content. Qualitative content derives from the mental image itself; for visual imaginings, it is what is “pictured.” For example, visually imagine the Philadelphia Eagles defeating the Pittsburgh Steelers to win their first Super Bowl. You picture the greenness of the field and (...) the football’s brown oblong shape. Some of what you imagine isn’t explicitly pictured, however. That it is Sunday, that it is the Super Bowl: these facts are assigned. (shrink)

Political decisions have the potential to greatly impact our lives. Think of decisions in relation to abortion or climate change, for example. This makes political legitimacy an important normative concern. But what makes political decisions legitimate? Are they legitimate in virtue of having support from the citizens? Democratic conceptions of political legitimacy answer in the affirmative. Such conceptions righly highlight that legitimate political decision-making must be sensitive to disagreements among the citizens. But what if democratic decisions fail to track what (...) there is most reason to do? What if a democratically elected government fails to take measures necessary to protect its population from threats related to climate change? Peter argues that the legitimacy of political decisions doesn't just depend on respect for the citizens' will; and defends a novel hybrid conception of political legitimacy, called the Epistemic Accountability conception. According to this conception, political legitimacy also depends on how political decision-making responds to evidence for what there is most reason to do. Grounds for Political Legitmacy starts with an overview of the main ways in which philosophers have thought about political legitimacy, and identifies the epistemic accountability conception as an overlooked alternative. It then develops the epistemic accountability conception of political legitimacy and discusses its implications for legitimate political decision-making. Considering the norms that should govern political debate, it examines the role of experts in politics, and probes the responsibilities of democratically elected political leaders and as well as of citizens. (shrink)