All associations are formed with the aim of achieving some good. The Greek city-state, or polis, is the most general association in the Greek world, containing all other associations, such as families and trade associations. As such, the city-state must aim at achieving the highest good. Aristotle concludes that “man is a political animal”: we can only achieve the good life by living as citizens in a state. In discussing the economic relations that hold within a city-state, Aristotle defends the institution of private property, condemns excessive capitalism, and notoriously defends the institution of slavery. Before presenting his own views, Aristotle discusses various theoretical and actual models current at his time. In particular, he launches lengthy attacks on Plato’s Republic and Laws, which most commentators find unsatisfying and off the mark, as well as criticizing other contemporary philosophers and the constitutions of Sparta, Crete, and Carthage.

Aristotle identifies citizenship with the holding of public office and administration of justice and claims that the identity of a city rests in its constitution. In the case of a revolution, where the citizenship and constitution change, a city’s identity changes, and so it cannot be held responsible for its actions before the revolution.

Roughly speaking, there are six kinds of constitution, three just and three unjust. A constitution is just when it benefits everyone in the city and unjust when it benefits only those in power. When a single person rules, a constitution is a monarchy if the ruler is good and a tyranny if the ruler is bad. When a small elite rules, a constitution is an aristocracy if the rulers are good and an oligarchy if the rulers are bad. When the masses rule, a constitution is a polity if they rule well and a democracy if they rule badly. Aristotle acknowledges that giving full sovereignty to either the governing body or the laws might make room for abuses of power and suggests that a polity is probably least susceptible to corruption, especially when the laws are given higher authority than the governing body. He proposes a principle of distributive justice, saying that benefits should be conferred upon different citizens differently, depending on the contribution they make to the well-being of the state.

In Books IV to VI, Aristotle turns from his theoretical speculations to a practical examination of political institutions as they exist in the Greek world. He observes that the needs of city-states vary greatly depending on their wealth, population, class distribution, and so on. He examines the different varieties of states and constitutions and makes a number of general recommendations. The greatest tension in any state is the mutual resentment between the rich and the poor. Consequently, a strong middle class keeps a state in balance and guards against corruption and oppression. The three branches of civic government are the deliberative, which makes the major political decisions of the state; the executive, which runs the day-to-day business of the state; and the judicial, which oversees the legal affairs of the state. Though it is not necessary to give everyone equal access to public office, it is never wise to exclude entirely any group from power. Constitutions are usually changed by a large, dissatisfied faction that rises up against the people in power. To preserve a constitution, Aristotle recommends moderation, education, and inclusiveness. The interests of the rich minority and poor majority can be balanced by allowing both factions a roughly equal amount of power. In such an arrangement, each individual rich person would have more political power than each individual poor person, but the poor and the rich as groups would be balanced against one another.

Books VII and VIII return to the question of what the ideal state would be like. The good life consists primarily in rational contemplation, so even though political action is admirable and necessary, it is only a means to the end of securing the ultimate happiness of rational contemplation. An ideal city-state should be arranged to maximize the happiness of its citizens. Such a city would be large enough for self-sufficiency but small enough to ensure fellow feeling. It should be located by the water to allow for easy sea commerce. Young citizens serve in the military, middle-aged citizens govern, and older citizens take care of religious affairs while noncitizen laborers take care of farming and crafts. Education is important to ensuring the well-being of the city, and Aristotle prefers a public program of education to private tutoring. He recommends that care be taken to breed the right habits in children from the time they are in the womb and that when they mature they learn to hone their reason. His recommended curriculum consists of reading and writing, physical education, music, and drawing. This education will help citizens make the most of both work and play, as well as the leisure time in which to pursue the good life.

Aristotle’s discussion of politics is firmly grounded in the world of the Greek city-state, or polis. He assumes that any state will consist of the same basic elements of a Greek city-state: male citizens who administer the state, and then women, slaves, foreigners, and noncitizen laborers who perform the necessary menial tasks to keep the city running. Citizenship in the Greek world was a much more involved responsibility than it is in modern representative democracies. All citizens in a Greek city-state take part in government and hold various public offices, which is why Aristotle takes public office as a defining feature of citizenship. Because citizenship involves an active role in running the state, a citizen identifies strongly with the city-state to which he belongs, to the point that the Greeks consider exile to be a fate worse than death. The tight bond between citizen and city-state also explains why Aristotle considers active citizenship as a necessary feature of the good life. He insists that we can only fully realize our rationality and humanity as citizens of a city-state, and so he concludes that fully realized humans are, by necessity, political animals.

Aristotle’s Politics is sometimes classified as “communitarian,” because it places the well-being of the community as a whole above the well-being of the individual. Aristotle calls humans “political animals” because we cannot be fully human without active participation in a city-state, and his recommendations regarding justice and education bear in mind only what will make for the strongest state. Absent entirely is the concern of modern liberalism with individual freedoms and the protection of a citizen’s private life from the public eye. Aristotle does not fail to discuss the tension between individual liberty and the demands of the state so much as he does not live in a world where this tension exists. The idea of a private life would seem absurd in a Greek city-state. All the highest aims in life, from political debate to physical exercise, take place in the public sphere, and there is no conception of a “private persona,” which differs from the face people present in public. Consequently, the interests of the individual and the interests of the state are equivalent in Aristotle’s view. His prioritizing of the community above the individual, as well as his warnings about the dangers of unrestrained capitalism, had a strong influence on the work of Karl Marx.

While Aristotle’s conception of distributive justice gives a clear indication of his own aristocratic leanings, much of Aristotle’s discussion of justice remains relevant to this day. Distributive justice is the idea that honors and wealth should be distributed according to merit, so that the best people get the highest rewards. Though Aristotle insists that “best” is a matter of merit, he seems unconcerned that the rich have much greater opportunities for achieving merit and that noncitizens, women, and slaves have no opportunity at all. Effectively, he condemns them to the lowest rung of the social ladder by insisting that benefits be accorded to those with merit and defining merit in terms of qualities that their low status bars them from. Despite these aristocratic leanings, however, Aristotle has a keen sense of the dangers of power abused. In book III, he discusses at length the difficulties of ensuring that all citizens are accountable. He is not the first to recommend that the written law have greater authority than the ruling class, but he makes the argument forcefully and it is largely thanks to his influence that we take the primacy of the law as a given in the modern world.

One of the less attractive features of the Politics is Aristotle’s endorsement of slavery, which, not surprisingly, rings hollow. His argument rests on the claim that everyone needs to be ruled and those who lack the rationality to rule themselves need to be ruled by others. Aristotle opposes the enslavement of other Greeks because he believes that all Greeks are at least somewhat rational beings and so their enslavement would be unjust. However, in typical Greek fashion, Aristotle regards all non-Greeks as inferior barbarians, many of whom can only live productively in a state of slavery. However, he also argues that slaves need sufficient rationality to understand and carry out the orders of their masters. This argument contradicts the argument that slaves deserve their lot because they lack rationality entirely. If we follow Aristotle’s reasoning to its logical conclusion, we can argue that slavery is always wrong because those who make capable slaves necessarily have a level of rationality that renders their enslavement unjust. Unfortunately, Aristotle himself was too caught up in the prejudices of his own time to recognize that his argument refutes itself.