Abstract

A committee has to address a complex question, the answer to which requires answering several sub-questions. Two different voting procedures can be used. On one procedure, the committee members vote on each sub-question and the voting results then are used as premises for the committee’s conclusion on the main issue. This premise-based procedure can be contrasted with the conclusion-based procedure. On that procedure, the members directly vote on the conclusion, with the vote of each member being guided by her views on the relevant sub-questions. These procedures are by no means equivalent, which has been pointed out in legal theory in connection with jury votes. There may be a majority of voters supporting each premise, but if these majorities do not significantly overlap, there will be a majority against the conclusion. Pettit connects the choice between the two procedures with general political theory, in particular, with the discussion of deliberative democracy. However, the problem we want to examine concerns the relative advantages and disadvantages of the two procedures from the epistemic point of view. In some cases one can assume that the question before the committee has the right answer. In cases like this, is one of the two procedures better when it comes to tracking the truth? As it turns out, the answer to this query is not univocal. On the basis of Condorcet’s jury theorem, we show that the premise-based procedure is clearly superior if the objective is reach truth for the right reasons, i.e. 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. Our results partly confirm and partly disconfirm the tentative conjectures that have been put forward in Pettit and Rabinowicz.