In Aristotle's view, men are, by their very nature, political animals. This means that the most natural thing for men to do is to come together in some form of political association. To do otherwise, to live outside of some form of human society, Aristotle says, is to be either a beast or a Deity; everyone not of one of those two classes must engage in some degree of social interaction with other human beings.

The greatest good for the citizenry as a whole is the chief goal of the state. Men are either just or unjust, good or evil, by inclination. Men may indeed be relied upon to seek their own good, but not all will recognize that their highest good is to be found in virtue. Since they are political by nature, it is the responsibility of the state to ensure that men are socialized to virtue. To properly run a state, the men of greatest virtue must somehow be selected to be the political leaders.

Now men come in two crude classes: rulers and ruled. Some men are naturally better suited to lead, while others are suited only to follow. The factors that determine which class a man belongs to are a combination of birth, wealth and achievement. Men of noble birth, Aristotle says, are endowed by race with superiority, that being a function of race. The wealthy, in owning the most land, may well be more reliable citizens since they have the greatest stake in the prosperity of the collective called the state. Those who distinguish themselves in the arts, military endeavour or professional life may also belong on this group. The masses, however, never rise to this level and are fit only to follow the instructions of those who exceed them in virtue.

For Aristotle, the mechanisms of human interaction arise from a specific teleology; that is, a larger purpose manifests itself naturally in the formation of various forms of association. States are formed from smaller degrees of associations, each with its own inherent – natural – ends. Individuals join together to form households in order to propagate the species and provide for their survival needs. A number of households may form a community or village in order to provide for common defense, a collaboration which furthers the goals of each individual household. So, too, do states form from collections of villages. The polis representing the highest form of association, the goals it pursues, the goods it seeks to further, are the highest ones. Being the most sovereign degree of association, it not only incorporates the goals of the associations below it, it strives to achieve still higher ones and does so to the greatest degree.

Aristotle's inclination is to moderation, the "Golden Mean." This further informs his Politics. Stability is chief among the goals he sets for a state and is always best achieved by seeking the middle ground. This end necessitates a number of compromises be incorporated into the constitution that best fits the local conditions of any given polis.

The aforementioned natural inequality among men gives rise to a number of distinctions that must be made between men conjoined in political association. High offices must be reserved for superior citizens. A monarchy that puts all decision-making power in the hands of only one (or a very few) will become unstable: Distributive justice, also known as proportional equality, requires that men be rewarded in accordance to their virtue, because those who deserve but are not accorded any honours will eventually rebel. But there must be more than one measure of competence. As noted above, while noble birth, wealth, and other superiorities are important, no one of them alone is sufficient to guarantee that the possessor is capable of good leadership. Only relevant measures of virtue should be used to determine who is fit to hold office and receive the honours of the state.

Those who are unsuited to rule must not be allowed to hold high office, but, if they are freemen and taxpayers, they cannot be shut out of the political process altogether. They must be allowed to sit on juries and to join on the selection of rulers.

Aristotle makes this assertion against oligarchy on several grounds. First, he recognizes the validity of collective wisdom: While each as an individual may not have sufficient virtue to make the best choices, their abilities taken as a whole they will likely evidence a greater degree of virtue than their superiors in virtue can in choosing their leaders.

Second, Aristotle recognizes that attention to public discourse and participation in public affairs improves the character of the people. Moral judgement, an essential component of virtue, is enhanced by being exercised. This furthers one of the state's chief ends: The promotion of the highest good of the people and the formation of men of good character.

Third, participation enhances compliance – not including free citizens in the political process would promote instability and revolution as a mass of freemen who were disenfranchised would chafe unduly under such a structure.

Lastly, to use Aristotle's example, a builder is not the only one capable of judging a house. The occupant may well see good and bad in the structure that the builder, for all his expertise, may miss. So, too, those who are affected by the policies of their leaders may be better suited to judge those policies than the rulers themselves.

Politics, being a practical art, the means of achieving the goals of the state will necessarily vary from one state to another. Aristotle eschews mandating the best possible form of government, asserting that local conditions will necessarily give rise to differences in constitutions from one polis to another. All told, the various considerations enumerated above lead Aristotle to suggest a "mixed" constitution, one that incorporates some aspects of both oligarchic and democratic structures: Reserve high offices to those best suited to hold them, but give the masses of freemen a role to play in the politics of the state. This, he avers, is the stable middle ground that forms the best foundation for a prosperous, state that can best achieve the highest good for the greatest number. But, as previously mention, Aristotle is most firmly opposed to the suggestion that one specific configuration is best suited to all populations. Rather, he insists that each state, as it forms, must take into account the various conditions that are unique to it and choose the degrees of oligarchy and democracy best suited to its needs as a unique political entity.