Completion requirements
Read this article for an overview of Aristotle's Politics. Aristotle describes how the ethically educated person, who has a proper character has an obligation to participate in their government (city-states in Aristotle's time). The moral health of one's city-state depends on the moral health of all the individuals who live in it and who participate in its political process. Because the city-state has such an interest in the moral health of each citizen, the government does have the right and the obligation to set laws that can be described as "paternalistic", laws that help people to control their own behavior even in private. In this sense Aristotle can be contrasted with modern day libertarian ethics.
Classification of constitutions
After studying a number of real and theoretical city-states' constitutions, Aristotle classified them according to various criteria. On one side stand the true (or good) constitutions, which are considered such because they aim for the common good, and on the other side the perverted (or deviant) ones, considered such because they aim for the well being of only a part of the city. The constitutions are then sorted according to the "number" of those who participate to the magistracies: one, a few, or many. Aristotle's sixfold classification is slightly different from the one found in The Statesman by Plato. The diagram above illustrates Aristotle's classification.