Full Idea
Socrates adopts the hypothesis that it is best for a city to be as far as possible entirely one. …But it is evident that the more a city becomes one the less of a city it will be. For a city is in its nature a sort of multitude.
Gist of Idea
A city can't become entirely one, because its very nature is to be a multitude
Source
Aristotle (Politics [c.332 BCE], 1261a14)
Book Reference
Aristotle: 'Politics', ed/tr. Reeve,C.D.C. [Hackett 2017], p.22
A Reaction
[He is referring to Plato's Republic] He says if a city wholly unifies it becomes like a household, and then a human being, rather than a city. A very interesting commitment to diversity in a city, based on its essential nature. Athens was very diverse.