David Estlund

Condorcet's Jury Theorem shows that on a dichotomous choice, individuals who all have the same competence above 0.5, can make collective decisions under majority rule with a competence that approaches 1 as either the size of the group or the individual competence goes up. The theorem assumes that the probability of each voter's being correct is independent of the probability of any other voter being correct. Contrary to several authors, the presence of mutual or common influences such as opinion leaders does not easily rule independence either in or out. Indeed, and this ought to be surprising,under certain conditions deference to opinion leaders can improve individual competence without violating independence, and so can raise group competence as well.

This piece is a response to four essays that critically discuss my book Democratic Authority. In addition to responding to their specific criticisms, it takes up several methodological issues that put some of the critiques in a broader context. Among the issues discussed are “normative consent,” which I offer as a new theory of authority; the “general acceptability requirement,” which advances a broadly Rawlsian approach to political justification; and methodological questions about theory building, including a device I dub the “method of provisional leap.”