Again, the situation of cities is a cause of revolution when the country is not naturally adapted to preserve the unity of the state.
 Aristotle, Politics (4th century BC). copy citation

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Author Aristotle
Source Politics
Topic unity revolution
Date 4th century BC
Language English
Reference
Note Translated by Benjamin Jowett
Weblink http://classics.mit.edu/Aristotle/politics.html

Context

“Now, in oligarchies the masses make revolution under the idea that they are unjustly treated, because, as I said before, they are equals, and have not an equal share, and in democracies the notables revolt, because they are not equals, and yet have only an equal share.
Again, the situation of cities is a cause of revolution when the country is not naturally adapted to preserve the unity of the state. For example, the Chytians at Clazomenae did not agree with the people of the island; and the people of Colophon quarrelled with the Notians; at Athens too, the inhabitants of the Piraeus are more democratic than those who live in the city.” source