Formal Social Epistemology

This article elaborates on foundational issues in the social sciences and their impact on the contemporary theory of belief revision. Recent work in the foundations of economics has focused on the role external social norms play in choice. Amartya Sen has argued in [Sen93] that the traditional rationalizability approach used in the theory of rational choice has serious problems accommodating the role of social norms. Sen's more recent work [Sen96, Sen97] proposes how one might represent social norms in the theory (...) of choice, and in a very recent article [BS07] Walter Bossert and Kotaro Suzumura develop Sen's proposal, offering an extension of the classical theory of choice that is capable of dealing with social norms. The first part of this article offers an alternative functional characterization of the extended notion of rationality employed by Bossert and Suzumura in [BS07]. This characterization, unlike the one offered in [BS07], represents a norm-sensitive notion of rationality in terms of a pure functional constraint unmediated by a notion of revealed preference (something that is crucial for the application developed in the second part of this article). This functional characterization is formulated for general domains (as is Bossert and Suzumura's characterization) and is therefore empirically more applicable than usual characterizations of rationality. Interestingly, the functional constraint we propose is a variant of a condition first entertained in [AGM85] by Carlos Alchourrón, Peter Gärdenfors and David Makinson in the area of belief change. The second part of this article applies the theory developed in the first part to the realm of belief change. We first point out that social norms can be invoked to concoct counterexamples against some postulates of belief change (like postulate (*7)) that are necessary for belief change to be relational. These examples constitute the epistemological counterpart of Sen's counterexamples against condition α in rational choice (as a matter of fact, Rott has showed in [Rot01] that condition and postulate (*7) are mutually mappable). These examples are variants of examples Rott has recently presented in [Rot04]. One of our main goals in this article consists in applying the theory developed in the first part to develop a theory of norm-inclusive belief change that circumvents the counterexamples. We offer a new axiomatization for belief change and we furnish correspondence results relating constraints of rational choice to postulates of belief change. (shrink)

We present a family of counter-examples to David Christensen's Independence Criterion, which is central to the epistemology of disagreement. Roughly, independence requires that, when you assess whether to revise your credence in P upon discovering that someone disagrees with you, you shouldn't rely on the reasoning that lead you to your initial credence in P. To do so would beg the question against your interlocutor. Our counter-examples involve questions where, in the course of your reasoning, you almost fall for an (...) easy-to-miss trick. We argue that you can use the step in your reasoning where you caught the trick as evidence that someone of your general competence level likely fell for it. Our cases show that it's permissible to use your reasoning about disputed matters to disregard an interlocutor's disagreement, so long as that reasoning is embedded in the right sort of explanation of why she finds the disputed conclusion plausible, even though it's false. (shrink)

An impossibility result for completely abstract social aggregation rules is presented. It is shown that non-imposition and a new no-veto property (two properties in the spirit of the Pareto principle and non-dictatorship respectively) are incompatible with an inter-profile consistency condition formulated in terms of proximity preservation.

This paper is about how to aggregate outside opinion. If two experts are on one side of an issue, while three experts are on the other side, what should a non-expert believe? Certainly, the non-expert should take into account more than just the numbers. But which other factors are relevant, and why? According to the view developed here, one important factor is whether the experts should have been expected, in advance, to reach the same conclusion. When the agreement of two (...) (or of twenty) thinkers can be predicted with certainty in advance, their shared belief is worth only as much as one of their beliefs would be worth alone. This expectational model of belief dependence can be applied whether we think in terms of credences or in terms of all-or-nothing beliefs. (shrink)

How should the opinion of a group be related to the opinions of the group members? In this article, we will defend a package of four norms pairs of prior probabilities and evidence. We show that there is a method of aggregating credal pairs that possesses all four virtues.

An allocation problem is a type of aggregation problem in which the values of individuals' opinions on some set of variables sum to a constant. This paper shows that for realistic allocation problems, namely ones in which the set of possible opinion values is finite, the only universal aggregation methods that satisfy two commonly invoked conditions are the dictatorial ones. The two conditions are, first, that the aggregate opinion on any variable depends only on the individuals' opinions on that variable (...) and not on their opinions on any other variable and, secondly, that the aggregate opinion minimally preserves unanimous individual opinion. Connections between this result and similar ones in the literature on judgment aggregation are explored and their significance assessed. (shrink)

Richard Jeffrey espoused an antifoundationalist variant of Bayesian thinking that he termed ‘Radical Probabilism’. Radical Probabilism denies both the existence of an ideal, unbiased starting point for our attempts to learn about the world and the dogma of classical Bayesianism that the only justified change of belief is one based on the learning of certainties. Probabilistic judgment is basic and irreducible. Bayesian conditioning is appropriate when interaction with the environment yields new certainty of belief in some proposition but leaves one’s (...) conditional beliefs untouched (the ‘Rigidity’ condition). Although Richard Jeffrey denied the general applicability of this condition, one of his main contributions to probabilistic thinking is a form of belief updating—now typically called ‘Jeffrey conditioning’ or ‘probability kinematics’—that is appropriate in circumstances in which Rigidity is satisfied, but where the interaction causes one to reevaluate one’s probability judgments over some partition of the possibility space without conferring certainty on any particular element. The most familiar occasion for Jeffrey conditioning is receipt of uncertain evidence: things partially perceived or remembered. But it also serves to illuminate belief updating occasioned by a change in one’s degrees of conditional belief, a kind of belief change largely ignored by classical Bayesianism. I argue that such changes in conditional belief can also be basic (in the sense of not being analyzable as a consequence of conditioning on factual information) and offer a kinematical model for a particular kind change in conditional belief. Both are applied to changes in preference. Finally, I argue that Rigidity can fail when changes of belief give inferential grounds for changes in conditional belief (and vice versa). These failures show that conditioning methods are properly regarded, not as valid rules of inference, but as tools in the ‘art of judgment’. (shrink)

Multiple-vote majority rule is a procedure for making group decisions in which individuals weight their votes on issues in accordance with how competent they are on them. When individuals are motivated by the truth and know their relative competence on different issues, multiple-vote majority rule performs nearly as well, epistemically speaking, as rule by an expert oligarchy, but is still acceptable from the point of view of equal participation in the political process.

Christian List and Philip Pettit argue that groups of people can be agents – beings that believe, desire and act. Their account combines a non-reductive realist view of group attitudes, on which groups literally have attitudes that cannot be analyzed in terms of the attitudes of their members, with methodological individualism, on which good explanations of group-level phenomena should not posit forces above individual attitudes and behaviors. I then discuss the main normative conclusion that LP draw from the claim that (...) group agents exist: that we ought morally to grant legal rights and responsibilities to group agents, but that group rights should be more limited than individual rights. I argue that when it comes to the fitness of group agents to bear legal rights and responsibilities, LP can draw support from nonreductionist views elsewhere, particularly in the philosophy of mind. I raise some objections to LP's views about the value of granting legal rights and responsibilities to group agents. (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)

I describe two concepts of epistemic injustice. The first of these concepts is explained through a critique of Alvin Goldman's veritistic social epistemology. The second is closely based on Miranda Fricker's concept of epistemic injustice. I argue that there is a tension between these two forms of epistemic injustice and tentatively suggest some ways of resolving the tension.

Ronald Dworkin argues that disagreement in hard cases is ‘theoretical’ rather than empirical and of central importance to our understanding of law, showing ‘plain fact’ theories such as H. L. A. Hart’s sophisticated legal positivism to be false. The argument from theoretical disagreement targets positivism’s commitment to idea that the criteria a norm must meet to be valid in a given jurisdiction are constituted by a practice of convergent behavior by legal officials. The ATD suggests that in hard cases there (...) is no such pattern of convergent behavior. Positivists are divided over the force of the ATD. Much of this disagreement over the force of the ATD can be understood as disagreement over just what it is that legal officials disagreeing ‘theoretically’ are disagreeing about. Once the scope of empirical and theoretical disagreements are more accurately plotted, we will see that the actual disagreements that occur in hard cases are not ones which threaten a deeper and pervasive pattern of convergent behavior, one which focuses not upon rules specifying criteria of legal validity, but instead upon broad processes for making, interpreting, and applying law. Such an account remains positivist, relying on the social fact that there is such a consensus, but allows for considerable disagreement among legal officials deciding cases within such procedures. (shrink)

The main question of this paper is: how do we manage to know what our own degrees of belief are? Section 1 briefly reviews and criticizes the traditional functionalist view, a view notably associated with David Lewis and sometimes called the theory-theory. I use this criticism to motivate the approach I want to promote. Section 2, the bulk of the paper, examines and begins to develop the view that we have a special kind of introspective access to our degrees of (...) belief. I give an initial assessment of the view by examining its compatibility with leading theories of introspection. And I identify a challenge for the view, and explain why I'm optimistic that the view can overcome it. (shrink)

Various authors have recently argued that you cannot rationally stick to your belief in the face of known disagreement with an epistemic peer, that is, a person you take to have the same evidence and judgmental skills as you do. For, they claim, because there is but one rational response to any body of evidence, a disagreement with an epistemic peer indicates that at least one of you is not responding rationally to the evidence. Given that you take your peer (...) to have the same judgmental skills as you do, and thus regard her to be equally good at assessing the evidence as you are, you will have as much reason for thinking that it is you who is not responding rationally to the evidence as for thinking that it is her. You thus have reason for thinking that your belief on the disputed matter is not a rational response to the evidence. Hence, you cannot rationally stick to your belief. (shrink)

List and Pettit have stated an impossibility theorem about the aggregation of individual opinion states. Building on recent work on the lottery paradox, this paper offers a variation on that result. The present result places different constraints on the voting agenda and the domain of profiles, but it covers a larger class of voting rules, which need not satisfy the proposition-wise independence of votes.

The paper considers the problem of how a distributed system of agents (who communicate only via a localised network) might achieve consensus by copying beliefs (copy) from each other and doing some belief pruning themselves (drop). This is explored using a social simulation model, where beliefs interact with each other via a compatibility function, which assigns a level of compatibility (which is a sort of weak consistency) to a set of beliefs. The probability of copy and drop processes occurring is (...) based on the increase in compatibility this process might result in. This allows for a process of collective consensus building whilst allowing for temporarily incompatible beliefs to be held by an agent. (shrink)

Common knowledge is usually defined as a state in which everyone knows that p, everyone knows that everyone knows that p, and so on, ad infinitum. This definition is usually attributed to David Lewis, despite the fact that his own formulation bears no resemblance to common knowledge as it is usually understood. In this paper, I argue that this concept of common knowledge requires revision. Contrary to usual practice, it turns out to be difficult to model formally because existing models (...) fail to distinguish between full-blown common knowledge and merely finite levels of interactive knowledge. Conceptually, the concept is incompatible with Lewis's intended purpose and obscures the explanatory role played by rational choice models. I propose that the concept of common knowledge be brought better into alignment with Lewis's actual formulation. This reconceptualization of common knowledge suggests a greater focus on explanations that make recourse to the cognitive constraints of real-world agents. (shrink)

An aggregation procedure merges a list of objects into a representative object. This paper considers the problem of aggregating n rows in an n-by-m matrix into a summary row, where every entry is an element in an algebraic field. It focuses on consistent aggregators, which require each entry in the summary row to depend only on its column entries in the matrix and to be the same as the column entry if the column is constant. Consistent aggregators are related to (...) additive, linear and.. (shrink)

This paper analyses the relations between philosophy of information (PI), library and information science (LIS) and social epistemology (SE). In the first section, it is argued that there is a natural relation between philosophy and LIS but that SE cannot provide a satisfactory foundation for LIS. SE should rather be seen as sharing with LIS a common ground, represented by the study of information, to be investigated by a new discipline, PI. In the second section, the nature of PI is (...) outlined as the philosophical area that studies the conceptual nature of information, its dynamics and problems. In the third section, LIS is defined as a form of applied PI. The hypothesis supported is that PI should replace SE as the philosophical discipline that can best provide the conceptual foundation for LIS. In the conclusion, it is suggested that the 'identity' crisis undergone by LIS has been the natural outcome of a justified but precocious search for a philosophical counterpart that has emerged only recently: namely, PI. The development of LIS should not rely on some borrowed, pre-packaged theory. As applied PI, LIS can fruitfully contribute to the growth of basic theoretical research in PI itself and thus provide its own foundation. (shrink)

In order to perform certain actions – such as incarcerating a person or revoking parental rights – the state must establish certain facts to a particular standard of proof. These standards – such as preponderance of evidence and beyond reasonable doubt – are often interpreted as likelihoods or epistemic confidences. Many theorists construe them numerically; beyond reasonable doubt, for example, is often construed as 90 to 95% confidence in the guilt of the defendant. -/- A family of influential cases suggests (...) standards of proof should not be interpreted numerically. These ‘proof paradoxes’ illustrate that purely statistical evidence can warrant high credence in a disputed fact without satisfying the relevant legal standard. In this essay I evaluate three influential attempts to explain why merely statistical evidence cannot satisfy legal standards. (shrink)

Sunstein's Infotopia offers four reasons for thinking that information-pooling via mechanical aggregation of votes is superior to discursive sharing of opinions. This article focuses on two of them—the Common Knowledge Effect and Group Polarisation—showing that both phenomena might have perfectly good Bayesian explanations. Far from constituting 'errors', both can actually contribute to truth-tracking in ways that cannot be accomplished via mechanical aggregation of votes alone.

Special issue. With contributions by Rogier De Langhe and Matthias Greiff, Igor Douven and Alexander Riegler, Stephan Hartmann and Jan Sprenger, Carl Wagner, Paul Weirich, and Jesús Zamora Bonilla.

The problem of the aggregation of consistent individual judgments on logically interconnected propositions into a collective judgment on the same propositions has recently drawn much attention. The dificulty lies in the fact that a seemingly reasonable aggregation procedure, such as propositionwise majority voting, cannot ensure an equally consistent collective outcome. The literature on judgment aggregation refers to such dilemmas as the discursive paradox. So far, three procedures have been proposed to overcome the paradox: the premise-based and conclusion-based procedures on the (...) one hand, and the merging approach on the other hand. In this paper we assume that the decision which the group is trying to reach is factually right or wrong. Hence, the question is how good the merging approach is in tracking the truth, and how it compares with the premise-based and conclusion-based procedures. (shrink)

This book elucidates the theoretical structure and scope of interpersonal and intra-personal aggregation--a trade-off between benefits to a group of individuals and losses to another group of individuals--and defends a form of aggregation -- formal aggregation -- that resolves a variety of outstanding problems arising from the conventional understanding of aggregation, including the Number Problem concerning the moral relevance of the number of individuals.

Considerations involving disagreement, as well as related considerations involving correction and retraction, have played an important role in recent debates about epistemic modals. For instance, it has been argued that contextualist views about epistemic modals have problems when it comes to explaining cases of disagreement. In response to these challenges, I explore the idea that the relevant cases of disagreement may involve credal disagreement. In a case of credal disagreement, the parties have different degrees of belief or credences. There does (...) not have to be a difference in outright beliefs in order for the parties to disagree. I argue that the idea of credal disagreement allows us to make sense of otherwise problematic cases of disagreement involving epistemic modals. I also discuss how these ideas can be extended to cases of correction and retraction. (shrink)