Aristotle pioneered the use of the term as meaning rule by the rich, for which another term commonly used today is plutocracy. In the early 20th century Robert Michels developed the theory that democracies, as all large organizations, have a tendency to turn into oligarchies.
B. Living in ethnic enclaves. This can be compared to modern times.
The County unit system. See the link below that will take you to that.
Sociology. the fundamental character or spirit of a culture; the underlying sentiment that informs the beliefs, customs, or practices of a group or society; dominant assumptions of a people or period: In the Greek ethos the individual was highly valued.