Aristotle lays the foundations for his political theory in Politics book I by arguing that the city- state and political rule are “natural.”
The argument begins with a schematic, quasi-historical account of the development of the city-state out of simpler communities. First, individual human beings combined in pairs because they could not exist apart. The male and female joined in order to reproduce, and the master and slave came together for self-preservation. The natural master used his intellect to rule, and the natural slave employed his body to labour.
Second, the household arose naturally from these primitive communities in order to serve everyday needs. Third, when several households combined for further needs a village emerged also according to nature. Finally, “the complete community, formed from several villages, is a city-state, which at once attains the limit of self-sufficiency, roughly speaking. It comes to be for the sake of life, and exists for the sake of the good life”.
Aristotle defends three claims about nature and the city-state: First, the city-state exists by nature, because it comes to be out of the more primitive natural associations and it serves as their end, because it alone attains self-sufficiency. Second, human beings are by nature political animals, because nature, which does nothing in vain, has equipped them with speech, which enables them to communicate moral concepts such as justice which are formative of the household and city-state.
Third, the city-state is naturally prior to the individuals, because individuals cannot perform their natural functions apart from the city-state, since they are not self-sufficient. These three claims are conjoined, however, with a fourth: the city-state is a creation of human intelligence. ‘Therefore, everyone naturally has the impulse for such a community, but the person who first established is the cause of very great benefits”. This great benefactor is evidently the lawgiver (nomothetes), for the legal system of the city-state makes human beings just and virtuous and lifts them from the savagery and bestiality in which they would otherwise languish.