Contemporary democratic theory has many mansions: theories of competi-tive, pluralistic, and deliberative democracy have generated large literatures.2Among more recent developments is “epistemic democracy,” which focuses on the quality of the decisions made by democratic groups. The core premise of theories of epistemic democracy is that the legitimacy of democracy as a sys-tem of governance ought to be predicated on the results of decision- making, and not only the procedural rules and practices. How good or bad decisions are ought to be testable against some independent criterion of value. Thus, even if a given decision is procedurally impeccable by democratic standards (e.g. it was predicated on strict standards of equality of influence among decision- makers and those affected by the decision), if the decision itself was substantively bad, the epistemic democrat will say that something has gone seriously wrong. De-cisions may be judged bad either by a deontological moral standard (e.g. the decision resulted in the violation of certain persons’ rights), or by a practical efficacy standard (e.g. the decision resulted in outcomes that were detrimental to welfare or security interests common to residents of the relevant commu-nity). If democratic decisions are to be substantively good, decision- making processes must aggregate privately- held useful knowledge as well as individual preferences or interests. In brief, a democracy may be said to be “epistemic” to the degree to which it employs collective wisdom to make good policy.