This paper generalises the classical Condorcet jury theorem from majority voting over two options to plurality voting over multiple options. The paper further discusses the debate between epistemic and procedural democracy and situates its formal results in that debate. The paper finally compares a number of different social choice procedures for many-option choices in terms of their epistemic merits. An appendix explores the implications of some of the present mathematical results for the question of how probable majority cycles (as in (...) Condorcet's paradox) are in large electorates. (shrink)

Consensus plays an ambiguous role in deliberative democracy. While it formed the horizon of early deliberative theories, many now denounce it as an empirically unachievable outcome, a logically impossible stopping rule, and a normatively undesirable ideal. Deliberative disagreement, by contrast, is celebrated not just as an empirically unavoidable outcome but also as a democratically sound and normatively desirable goal of deliberation. Majority rule has generally displaced unanimity as the ideal way of bringing deliberation to a close. This article offers an (...) epistemic perspective on this question of consensus versus disagreement. For ensuring the production of better decisions, we argue, the normative appeal of consensus varies depending on the deliberative task – whether it entails problem solving or prediction. We argue that in pure problem-solving contexts, consensus retains a strong normative appeal and forms the ideal deliberative outcome of deliberation. In contrast, on predictive tasks, consensus should generally not be used as a stopping rule noris it likely to be epistemically desirable as an outcome. Instead deliberators may be better served by ending the deliberation with a form of deliberative disagreement we call ‘positive dissensus’, which paves the way for more accurate aggregate predictions. (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)