<span>A system of beliefs or ideas that justifies the social, moral, religious, political, or economic interests held by a group or by society is often called an "ideology" or an "agenda". </span>
A Juxtaposition of God and the Human Brain
Hey there!
The system used for lots of city-states (started in Athens) was that you had to be a free male (meaning not a slave) born in that city-state, over the age of 18.
Hope this helps!