Aristotle, Politics

[1328a] [1] A sign of this is that spirit is more roused against associates and friends than against strangers, when it thinks itself slighted. Therefore Archilochus¹ for instance, when reproaching his friends, appropriately apostrophizes his spirit: “ For 'tis thy friends that make thee choke with rage.
” Moreover it is from this faculty that power to command and love of freedom are in all cases derived; for spirit is a commanding and indomitable element. But it is a mistake to describe the Guardians as cruel towards strangers; it is not right to be cruel towards anybody, and men of great-souled nature are not fierce except towards wrongdoers, and their anger is still fiercer against their companions if they think that these are wronging them, as has been said before. And this is reasonable, because they think that in addition to the harm done them they are also being defrauded of a benefit by persons whom they believe to owe them one. Hence the sayings “ For brothers' wars are cruel,²
” and “ They that too deeply loved too deeply hate.³
”

We have now approximately decided what are the proper numbers and the natural qualities of those who exercise the right of citizens, and the proper extent and nature of the territory （for we must not [20] seek to attain the same exactness by means of theoretical discussions as is obtained by means of the facts that come to us through sense-perceptions）.

But since, just as with all other natural organisms those things that are indispensable for the existence of the whole are not parts⁴ of the whole organization, it is also clear that not all the things that are necessary for states to possess are to be counted as parts of a state （any more than this is so with any other association that forms something one in kind, for there must be something that is one and common and the same for the partners, whether the shares that they take be equal or unequal: for example this common property may be food or an area of land or something else of the same sort—⁵ but when of two related things one is a means and the other an end, in their case there is nothing in common except for the one to act and the other to receive the action. I mean for instance the relation between any instrument or artificer and the work that they produce: between a house and a builder there is nothing that is produced in common, but the builder's craft exists for the sake of the house. Hence although states need property, the property is no part of the state. And there are many living things that fall under the head of property.⁶ And the state is one form of partnership of similar people, and its object is the best life that is possible. And since the greatest good is happiness, and this is some perfect activity or employment of virtue, and since it has so come about that it is possible for some men to participate in it, but for others only to a small extent or not at all, it is clear that this is the cause for there arising different kinds and varieties of state and several forms of constitution;