The reason for there being many different sorts of governments is this, that each state consists of a great number of parts; for, in the first place, we see that all cities are made up of families: and again, of the multitude of these some must be rich, some poor, and others in the middle station; and that, both of the rich and poor, some will be used to arms, others not. We see also, that some of the common people are husbandmen, others attend the market, and others are artificers. There is also a difference between the nobles in their wealth, and the dignity in which they live: for instance, in the number of horses they breed; for this cannot be supported without a large fortune: for which reason, in former times, those cities whose strength consisted in horse became by that means oligarchies; and they used horse in their expeditions against the neighbouring cities; as the Eretrians the Chalcidians, the Magnetians, who lived near the river Meander, and many others in Asia. Moreover, besides the difference of fortune, there is that which arises from family and merit; or, if there are any other distinctions [1290a] which make part of the city, they have been already mentioned in treating of an aristocracy, for there we considered how many parts each city must necessarily be composed of; and sometimes each of these have a share in the government, sometimes a few, sometimes more.

It is evident then, that there must be many forms of government, differing from each other in their particular constitution: for the parts of which they are composed each differ from the other. For government is the ordering of the magistracies of the state; and these the community share between themselves, either as they can attain them by force, or according to some common equality which there is amongst them, as poverty, wealth, or something which they both partake of. There must therefore necessarily be as many different forms of governments as there are different ranks in the society, arising from the superiority of some over others, and their different situations. And these seem chiefly to be two, as they say, of the winds: namely, the north and the south; and all the others are declinations from these. And thus in politics, there is the government of the many and the government of the few; or a democracy and an oligarchy: for an aristocracy may be considered as a species of oligarchy, as being also a government of the few; and what we call a free state may be considered as a democracy: as in the winds they consider the west as part of the north, and the east as part of the south: and thus it is in music, according to some, who say there are only two species of it, the Doric and the Phrygian, and all other species of composition they call after one of these names; and many people are accustomed to consider the nature of government in the same light; but it is both more convenient and more correspondent to truth to distinguish governments as I have done, into two species: one, of those which are established upon proper principles; of which there may be one or two sorts: the other, which includes all the different excesses of these; so that we may compare the best form of government to the most harmonious piece of music; the oligarchic and despotic to the more violent tunes; and the democratic to the soft and gentle airs.