 Socrates then launches a speculation as to the origins of cities: the city is held to have an existence independently of ethical concerns, coming into being for economic reasons and immediately needing to defend itself in war (and also to be able to make offensive war for economic gain). However, this origin already gives rise to a proto-ethical dimension, first insofar as the members of the primitive city each do their own work (the structure of what will emerge as the virtue of justice), which is fleshed out when political rulers are established who are able to use their wisdom to help their subjects maintain a psychological balance in their souls that approximates, if it does not fully embody, the virtues of moderation and justice and so enables them to enjoy a unified rather than a divided soul. The question of why the individual should be just, figured at the outset by the contrast with the putatively happy tyrant, is resolved eventually by demonstrating that the tyrant will necessarily, in virtue of the disorder of his soul, be at once maximally unjust and maximally unhappy.