Would a person be happy if he was the only living person in the world? No. Aristotle says that “man is by nature a political animal” [3] , because he is the only amongst the animals that “has the ability to communicate his ideas about justice and the good” [4] ; he alone amongst the animals has speech. This allows us to say that human partnerships are natural and so are cities, because they arise from smaller human partnerships, the villages and the households. A city is autarkic [5] , meaning that it contains everything that is necessary to live a good life; “it originated for the sake of basic survival, but exists for the sake of living well”. Living well requires a life according to virtue since, as Aristotle says “the best way of life both separately for each individual and in common for cities is that accompanied by virtue”; that life will result in happiness, which is the aim of human life. That means that the best form of political arrangement should care for virtue. Moreover, it means that justice should be very important for every city, since “a city can only foster virtue to the extent that it is just”.