According to Aristotle, the end goal of human life is happiness, which is found in the application of reason. Ancient Greece was divided into small city-states, and these poleis meant much more to their inhabitants than modern cities do to theirs. The interests of a polis and those of its citizens were seen as identical, since both city and man aimed for happiness. This life of good quality is not possible except within the confines of a city. This idea continues with the belief that man needs the leisure and the social interaction that citizens in a polis have in order to enjoy achieving this happiness. Consequently, non-citizens are unable to attain true happiness or rationality and are thus less complete, less human than citizens.
Aristotle’s belief that man can only become fully human when he engages in the political association of the city is a strongly communitarian view that would meet with heavy opposition from libertarian thinkers. By asserting that man fails to fulfill his ultimate purpose when he is disconnected from the state, Aristotle is not simply arguing that the laws of the state should restrict man’s freedom; he is arguing that life itself has no value outside the confines of the state. To realize his true human nature, man must take part in political life, and so, Aristotle concludes, he is a political animal. And only as part of a city can people fully realize their nature; separated from the city they are worse than animals.