All constituted governments are, to some degree, necessarily centralized, in the sense that a theoretically federal state exerts an authority or prerogative beyond that of its constituent parts. To the extent that a base unit of society — usually conceived as an individual citizen — vests authority in a larger unit, such as the state or the local community, authority is centralized. The extent to which this ought to occur, and the ways in which centralized government evolves, forms part of social contract theory.