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).