Suppose a committee or a jury confronts a complex question, the answer to which requires attending to several sub-questions. Two different voting procedures can be used. On one, the committee members vote on each sub-question and the voting results are used as premises for the committee’s conclusion on the main issue. This premise-based procedure can be contrasted with the conclusion-based approach, which requires the members to directly vote on the conclusion, with the vote of each member being guided by her (...) views on the relevant sub-questions. The two procedures are not equivalent: There may be a majority of voters supporting each of the premises, but if these majorities do not significantly overlap, there will be a majority against the conclusion. Pettit (2001) connects the choice between the two procedures with the discussion of deliberative democracy. The problem we want to examine instead concerns the relative advantages and disadvantages of the two procedures from the epistemic point of view. Which of them is better when it comes to tracking truth? As it turns out, the answer is not univocal. On the basis of Condorcet’s jury theorem, the premise-based procedure can be shown to be superior if the objective is reach truth for the right reasons, without making any mistakes on the way. However, if the goal instead is to reach truth for whatever reasons, right or wrong, there will be cases in which using the conclusion-based procedure turns out to be more reliable, even though, for the most part, the premise-based procedure will retain its superiority. (shrink)

A thought, taken as a propositional attitude or the content of psychological predicates such as believe, wish, desire, hope, is ascribed to an entity with mental states. A thought is not only allegedly ascribed to particular non-mental things like computer, book, it is also ascribed to non-material things, linguistically in plural terms, e.g. plural pronouns (e.g. we, they), collective names or singular proper names (e.g. the United States), proper names in plural form or general terms (e.g. the Microsoft, feminists). Plural (...) terms are terms referring to groups of entities. The question is - what is it for a group to have a thought? Two main views are currently on centered stage – the literal view and the metaphorical view. This paper argues that the main argument supporting the literal view, in particular Pettit’s view, faces three main problems, namely, the problem of rule-following in propositional coawareness, the problem of an independent verifiability for group beliefs and the problem of the indexical ‘we’- thought. -/- Keywords: thoughts, collective intentionality, social ontology, group agency, group consciousness . (shrink)

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers (...) new to the field of judgment aggregation a sense of this rapidly growing research area. (shrink)

We consider a panel of experts asked to assign probabilities to events, both logically simple and complex. The events evaluated by different experts are based on overlapping sets of variables but may otherwise be distinct. The union of all the judgments will likely be probabilistic incoherent. We address the problem of revising the probability estimates of the panel so as to produce a coherent set that best represents the group’s expertise.

The doctrinal paradox shows that aggregating individual judgments by taking a majority vote does not always yield a consistent set of collective judgments. Philip Pettit, Luc Bovens, and Wlodek Rabinowicz have recently argued for the epistemic superiority of an aggregation procedure that always yields a consistent set of judgments. This paper identifies several additional epistemic advantages of their consistency maintaining procedure. However, this paper also shows that there are some circumstances where the majority vote procedure is epistemically superior. The epistemic (...) value of maintaining consistency does not always outweigh the epistemic value of making true judgments. (shrink)

I present an original model in judgment aggregation theory that demonstrates the general impossibility of consistently describing decision-making purely at the group level. Only a type of unanimity rule can guarantee a group decision is consistent with supporting reasons, and even this possibility is limited to a small class of reasoning methods. The key innovation is that this result holds when individuals can reason in different ways, an allowance not previously considered in the literature. This generalizes judgment aggregation to subjective (...) decision situations, implying that the discursive dilemma persists without individual agreement on the logical constraints. Notably, the model mirrors the typical method of choosing political representatives, and thus suggests that no voting procedure other than unanimity rule can guarantee representation that reflects electorate opinion. Finally, I apply the results to a normative argument for unanimity rule in contract theory and juries, as well as to problems posed for deliberative democratic theory and the concept of representation. (shrink)

The constitution of a collective judgment is analyzed from a contractarian point of view. The optimal collective judgment is defined as the one that maximizes the sum of the utility each member gets from the collective adoption of that judgment. It is argued that judgment aggregation is a different process from the aggregation of information and public deliberation. This entails that the adoption of a collective judgment should not make any rational member of the group change her individual opinion, and (...) so the collective judgment can not have any kind of epistemic superiority over the individual ones. ‡The author acknowledges Spanish Government's research projects HUM2005–01686/FISO and HUM2005-25447-E, as well as the grant PR2006-0108 which allowed a three months stay at the Helsinki Collegium for Advanced Studies, in which a big part of this paper was written. †To contact the author, please write to: Universidad Nacional de Educación a Distancia, Dpto. de Lógica, Historia y F. de la ciencia, Humanidades, Paseo de Senda del rey 7, 28040 Madrid, Spain; e-mail: [email protected]. (shrink)

A standard objection to a market in political votes is that it will enable the rich politically to dominate the poor. If a market in votes was allowed then the poor would be the most likely sellers and the rich the most likely buyers. The rich would thus accumulate the votes of the poor, and so the candidates elected and the policies passed would represent only their interests and not those of the electorate as a whole. To ensure that the (...) poor do not become de facto disenfranchised, then, markets in votes should be disallowed. This objection seems so straightforward and compelling that it has received almost no critical scrutiny. This is unfortunate, for close examination reveals that this argument is not as straightforward as it initially appears. Indeed, there are four different ways of understanding this objection. It could be understood as expressing: the concern that markets in votes would enable candidates to win elections who would otherwise lose them; the concern that they would enable the election of candidates opposed by the majority of the electorate; the concern that they would lead to the poor having disproportionately low political influence; and the concern that they would lead to the rich having disproportionately high political influence. I will argue in this paper that only and could plausibly ground objections to markets in votes. Moreover, these will only plausibly ground objections to unrestricted markets in votes; they will not ground objections to markets in votes per se. Thus, if we are to continue to object to markets in political votes we will have to do this on grounds other than that were they to be allowed the rich will politically dominate the poor. (shrink)

My focus is on aggregation of individual value rankings of alternatives to a collective value ranking. This is compared with aggregation o individual prefrences to a collective preference. While in an individual preference ranking the alternatives are ordered in accordance with one’s preferences, the order in a value ranking expresses one’s comparative evaluation of the alternatives, from the best to the worst. I suggest that, despite their formal similarity as rankings, this difference in the nature of individual inputs in two (...) aggregation scenarios has important implications: The kind of procedure that looks fine for aggregation of judgments is inappropriate for aggregation of preferences. The procedure I have in mind consists in similarity maximization, or – more precisely – in minimization of the average distance from individual inputs. When applied to judgment aggregation, this procedure can also be approached from the epistemic perspective: the questions are posed concerning its advantages as a truth-tracker. From that perspective, what matters is not only the probability of the outcome of the procedure being true, but also the expected verisimilitude of the outcome: its expected distance from truth. (shrink)

The article discusses the implications of the well‐known discursive dilemma. The dilemma arises whenever a reasoned decision has to be taken by a collective decision‐maker and generates persistent contradiction between what is defined as collective reason and public opinion. Following Philip Pettit, I argue that collective reason is normatively preferable and that the role of existing constitutional institutions in contemporary democracies is to collectivise reason. However, this makes the frustration of popular will a systematic by‐product of any well‐functioning political process. (...) I argue that the only way out is if individual beliefs are subject to revision during cycles of public deliberations with the responsibility to lead this thrusted upon elected representatives. (shrink)

BackgroundPublic involvement activities are promoted as measures for ensuring good governance in challenging fields, such as biomedical research and innovation. Proponents of public involvement activities include individual researchers as well as non-governmental and governmental organizations. However, the concept of ‘public’ in public involvement deserves more attention by researchers because it is not purely theoretical: it has important practical functions in the guidance, evaluation and translation of public involvement activities.DiscussionThis article focuses on collective agency as one property a public as a (...) small group of participants in a public involvement activity could exhibit. It introduces a prominent theoretical approach to collective agents as one specific kind of social entities and demonstrates how this approach can be applied to current practice in public involvement activities. A brief discussion of different types of representation as they are used in the existing literature on this topic is also included because representation and collective agency can be closely related to each other. Suggestions and ideas that are derived from this reasoning include the proposal to use a ‘validity check’ for the generation of collective agents as a regular element of certain types of public involvement activities, the consequences of combining collective agency and representativeness as a further property a public could exhibit, and standards for reporting the content of public involvement activities in scientific publications.SummaryThis article discusses the importance of the concept of ‘public’ in public involvement activities, with a focus on biomedical research and innovation. It introduces various practically relevant ideas that are based on a theoretical analysis of collective agency as an important property a public can possess. (shrink)

La démocratie délibérative s’oppose fréquemment à une conception rationnelle du citoyen qui, selon ses théoriciens, ne permet pas d’atteindre une authentique démocratie. Pourtant, la démocratie délibérative souffre elle-même de difficultés théoriques importantes dont une partie des solutions a déjà été abordée dans la théorie du choix rationnel. Nous voulons montrer que le choix rationnel, dans sa version « étendue », peut servir à améliorer la démocratie délibérative sans pour autant en ébranler ses fondements. Nous effectuerons d’abord un survol de la (...) démocratie délibérative, en insistant sur les questions de formation et d’expression des préférences des citoyens dans l’agora. Nous y découvrirons certaines difficultés théoriques que nous tenterons par la suite de résoudre par un ensemble de mécanismes issus de la théorie du choix rationnel. Parallèlement, nous verrons que la délibération raisonnable est possible dans un paradigme rationnel, que nous appelons la « délibération circonstancielle ».Deliberative democracy frequently rejects the rational citizen model since, according to its proponents, it would not yield a proper democracy. And yet, deliberative democracy contains important theoretical difficulties, some of which have been dealt with by rational-choice theory. We intend to show that a “broad” version of rational-choice theory can actually improve deliberative democracy without condemning its foundations. First, we will briefly examine deliberative democracy, focusing on the formation and expression of citizens’preferences in the agora. Some theoretical problems will be identified; several mechanisms drawn from rational-choice theory will be used to try to solve them. Simultaneously, we will see that reasonable deliberation is possible in a rational-choice paradigm, in a model I call “circumstantial deliberation”. (shrink)

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers (...) new to the field of judgment aggregation a sense of this rapidly growing research area. (shrink)

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)

Drawing on the so-called “doctrinal paradox”, List and Pettit (2002) have shown that, given an unrestricted domain condition, there exists no procedure for aggregating individual sets of judgments over multiple interconnected propositions into corresponding collective ones, where the procedure satisfies some minimal conditions similar to the conditions of Arrow’s theorem. I prove that we can avoid the paradox and the associated impossibility result by introducing an appropriate domain restriction: a structure condition, called unidimensional alignment, is shown to open up a (...) possibility result, similar in spirit to Black’s median voter theorem. Specifically, I prove that, given unidimensional alignment, propositionwise majority voting is the unique procedure for aggregating individual sets of judgments into collective ones in accordance with the above mentioned minimal conditions. (shrink)

In this paper, I explore the possibility of applying the methods and results of Judgement Aggregation to the problem of logical disagreement. I develop and evaluate different ways in which individuals who logically disagree can generate a collective logic. I prove a version of the discursive paradox, where the majority voting of a group of structural logicians can give rise to a substructural logic; then I develop a more general impossibility result. After this, I analyze different ways to avoid the (...) paradox, in particular some methods which appeal to domain restrictions. Finally, I consider the application of these results to the discussion on semantic paradoxes. (shrink)