Mixed government, also known as a mixed constitution, defines a constitution in which the form of government is a combination of democracy, aristocracy, and monarchy, making impossible their respective degenerations (anarchy, oligarchy and tyranny). The idea was popularized during classical antiquity in order to describe the stability, the innovation and the success of the Republic as developed within the Roman Constitution. It is commonly treated as an antecedent of  separation of powers because in such a system some issues are decided by many (democracy), some other issues by few (aristocracy), and some other issues by a single person (monarchy). Unlike classical democracies, aristocracies, and monarchies, a mixed government is ruled by elected citizens rather than inherited or sorted (at the Greco-Roman time, sortition was conventionally regarded as the principal characteristic of Classical democracy).