How we cite our quotes: (Book.Chapter.Bekker #s); all Bekker line numbers are approximate, since they are keyed to the original Greek.
Quote #10
For in every community, something just seems to exist, and friendship as well. At any rate, people address their shipmates and fellow soldiers as friends, just as those in other communities do. And to the extent that people share in community, there is friendship, since to this extent there is also what is just. The proverb "the things of friends are in common" is correct, since friendship resides in community... (8.9.1159b27-33)
Aristotle makes the argument that the political sphere—the regime—determines the types of friendships can thrive in it. This makes sense, since friendships are a kind of micro-community, a reflection of the larger community around them. The level of justice that exists in society, then, determines what can exist between friends. Friends also must spend their days together, which means that they will live their lives in common, wishing for and doing the same kinds of things—hence, a community of two.