Democracy is a term that is used to denote a variety of distinct objects and ideas. Democracy describes either a set of political institutions or an ideal of collective self-rule. Democracy can also be short for a normative principle of either legitimacy or justice. Finally, democracy might be used to denote an egalitarian attitude. These four uses of the term should be kept distinct and raises separate conceptual and normative issues. The value of democracy, whether democratic political institutions or democratic self-rule, is either instrumental, non-instrumental, or both. The non-instrumental value of democracy derives either from the alleged fairness of majority rule or from the value of the social relationships enabled by participation in democratic procedures. The instrumental value of democracy lends support from a growing body of empirical research. Yet, the claim that democracy has a positive causal effect on public goods is inconclusive with respect to the moral justification of democratic institutions. Normative reasons for democracy’s instrumental value must instead appeal to the fact that it contributes to equality, liberty, truth, or the realization of popular will. Democracy as a principle of either political legitimacy or justice is a normative view that evades concerns with the definition and value of democracy. Normative democracy is a claim about the conditions either for legitimacy or justice of either public authority or coercion. Debates in normative democracy are largely divorced from the conceptual and empirical concerns that inform studies of democracy elsewhere. The boundaries of the people entitled to participate in collective decisions is a question that applies to all four uses of democracy. The boundary question raises three distinct issues. The first is the extent of inclusion required among the members of the unit. The second is if membership in the unit is necessary for inclusion or if people that are not recognized as members are on certain conditions also entitled to participate. The third and final issue concerns the boundaries of the unit itself.