Aristotle categorized the forms of government by dividing into three basic forms. There are Monarchy, Aristocracy and Mix Government. His study also includes the Tyranny, Oligarchy and Democracy government. This traditional classification is based on two main principles. First principle is if certain possess sovereignty, his running is known as monarchy. Second principle is if sovereign belongs to a small group of the population, it is known as aristocracy. However, if sovereign held by large group in population or known as Polity. Aristotle differentiates the forms of government by classifying them into two parts. First part is Normal Government. Then, second is Abnormal Government. Normal Government is a government that rules based on laws and justice. Ruling normally has the objective to increase harmonization and peace in the country as well as to avoid cruelty and coercion. Examples for Normal Government are Monarchy, Aristocracy and Polity government. The Abnormal Government forms are Tyranny, Oligarchy and Democracy. According to Aristotle, Monarchy is the best form of government, whereas Tyranny is the worst form of government. Aristotle believes that Democracy is a form of rule administer by a large group of people. He also believes Democracy is not too good because too many opinion and conflicts. Aristotle’s classification was constantly criticized by the political philosophers as they believe was the classification done by Aristotle was not based on the principles of political science. Aristotle’s classification did not explain the modern form of government such as Constitutional Monarchy, Unitary and Federal Government, Parliamentary and Presidential Government. Aristotle did not make future assumptions that there will be more forms of government developing. Because of too much weakness in Aristotle’s theory, the Modern writers suggest three forms of government. There are Aristocracy, Monarchy and Democracy. It is used until the end of the World War 2.