|Part of the Politics series|
|Basic forms of
Mixed government, also known as a mixed constitution, is a form of government that integrates elements of democracy, aristocracy, and monarchy. In a mixed government, some issues (often defined in a constitution) are decided by the majority of the people, some other issues by few, and some other issues by a single person (also often defined in a constitution). The idea is commonly treated as an antecedent of separation of powers.
Ancient Greek philosophers 
- democracy: government by the many
- oligarchy: government by the few
- timocracy: government by the honored or valued
- tyranny: government by one for himself
- aristocracy: government by the best (Plato's ideal form of government)
He found flaws with all existing forms of government and thus concluded that aristocracy, which emphasizes virtue and wisdom, is the purest form of government. Aristotle largely embraced Plato's ideas and in his Politics three types (excluding timocracy) are discussed in detail. Aristotle considers constitutional government (a combination of oligarchy and democracy under law) the ideal form of government, but he observes that none of the three are healthy and that states will cycle between the three forms in an abrupt and chaotic process known as the kyklos or anacyclosis. In his Politics he lists a number of theories of how to create a stable government. One of these options is creating a government that is a mix of all three forms of government.
Polybius argued that most states have a government system that is composed of "more than one" of these basic principles, which then was called a mixed government system.
Roman Era 
The ideal of a mixed government was popularized by Polybius, who saw the Roman Republic as a manifestation of Aristotle's theory. Monarchy was embodied by the consuls, the aristocracy by the Senate, and democracy by the elections and great public gatherings of the assemblies. Each institution complements and also checks the others, presumably guaranteeing stability and prosperity. Polybius was very influential and his ideas were embraced by Cicero.
Middle Ages 
St. Thomas Aquinas argued in his letter On Kingship that a monarchy, with some limitations set by an aristocracy and democratic elements, was the best and most just form of government. He also emphasized the monarch's duty to uphold the divine and natural law and abide by limitations imposed on the monarch by custom and existing law.
Renaissance and Enlightenment 
Cicero became extremely well regarded during the Renaissance and many of his ideas were embraced. Polybius was also rediscovered and the positive view of mixed governments became a central aspect of Renaissance political science integrated into the developing notion of republicanism. Mixed government theories became extremely popular in the Enlightenment and were discussed in detail by Hobbes, Locke, Vico, Montesquieu, Rousseau, and Kant. Apart from his contemporaries, only Montesquieu became widely acknowledged as the author of a concept of separation of powers (although he wrote rather on their "distribution").
According to some scholars[who?] the notion also influenced the writers of the United States Constitution who based the idea of checks and balances upon the ancient theory. The constitution of Britain during the Victorian Era with a Parliament composed of the Sovereign (monarchy), a House of Lords (aristocracy) and House of Commons (democracy) is a prime example of a mixed constitution in the 19th century.
Modern views 
One school of scholarship, based mainly in the United States, consider mixed government to be the central characteristic of a republic, and hold that the U.S. has rule by the one (the President), the few (the Senate, which was originally supposed to represent the States), and the many (House of Representatives). According to Frank Lovett this school is largely defunct.
Yet another school of thought in the United States says the Supreme Court has taken on the role of "The Best" in recent decades, ensuring a continuing separation of authority by offsetting the direct election of senators and preserving the mixing of Monarchy, Democracy, Republic, Oligarchy, and Military divisions of the federal government.
See also 
- Constitutional economics
- Fusion of powers
- Rule according to higher law
- Plato's Republic
- Aristotle's Politics
- Separation of powers
- Polybius and the Founding Fathers: the separation of powers
- De Republica Anglorum, Sir Thomas Smyth's description of the English Constitution under Queen Elizabeth I