A Constructivist Application of the Condorcet Jury Theorem

ELEONORA CRESTO

Praga

Congreso; CLMPST 2019 (Congress in Logic, Methodology, and Philosophy of Science and Technology); 2019

DLMPST (Division of Logic, Methodology, and Philosophy of Science and Technology)

The Condorcet Jury Theorem (CJT) tells us (roughly) that a group deciding on a yes or no issue by majority voting will be more reliable than any of its members, and will be virtually infallible when the number of members tends to infinity, provided a couple of conditions on individual reliability and independence are in place. Normally, the CJT presupposes the existence of some objective fact of the matter (or perhaps moral fact) F, whose truth (or desirability) does not depend on the method used to aggregate different opinions on whether F holds/ should hold. Thus, the CJT has been vindicated by advocates of epistemic democracy (with some caveats), while this move has typically been unavailable to authors with sympathies for proceduralist or constructivist accounts.In this paper I suggest an application of the CJT in which the truth/correctness of F is a direct result of the action of voting. To this effect I consider a n-person generalization of the stag hunt game, in which a stag is hunt only if there is a majority of hunters choosing stag. I show how to reinterpret the independence and competence conditions of the CJT to fit the example, and how to assess the import of the infallibility result in the present context of discussion. As a result of this we are able to identify both a selfish and a cooperative instance of the theorem, which help us draw some morals on what we may call ?epistemic optimism?. More generally, the proposal shows that we can establish links between epistemic and purely procedural conceptions of voting; this, in turn, can lead to novel ways to understand the relation between epistemic and procedural democracy.