You cannot make a city of ten men, and if there are a hundred thousand it is a city no longer.
 Aristotle, Nicomachean Ethics (c. 334 BC - 330 BC). copy citation

add
Author Aristotle
Source Nicomachean Ethics
Topic city
Date c. 334 BC - 330 BC
Language English
Reference
Note Translated by W. D. Ross
Weblink http://classics.mit.edu/Aristotle/nicomachaen.mb.txt

Context

“Of friends made with a view to pleasure, also, few are enough, as a little seasoning in food is enough. But as regards good friends, should we have as many as possible, or is there a limit to the number of one's friends, as there is to the size of a city? You cannot make a city of ten men, and if there are a hundred thousand it is a city no longer. But the proper number is presumably not a single number, but anything that falls between certain fixed points. So for friends too there is a fixed number perhaps the largest number with whom one can live together” source