Book 4
1289b
Now the reason of there being several forms of constitution is that every city has a considerable number of parts. For in the first place we see that all the cities are composed of households, and then again that of this multitude some must necessarily be rich and some poor and some between the two, and also of the rich and the poor the former class is heavy-armed and the latter without armor. And we see that one portion of the common people is agricultural, another engaged in trade and another mechanic. And the upper classes have distinctions also corresponding to their wealth and the amounts of their property (for example in a stud of horses—for it is not easy to rear horses without being rich, and this is why in ancient times there were oligarchies in all the states whose strength lay in their cavalry, and they used to use horses for their wars against their neighbors, as for instance did the Eretrians and Chalcidians and the people of Magnesia on the Maeander and many of the other Asiatic peoples). Moreover in addition to differences in wealth there is the difference of birth, and that in regard to virtue,
