The Ancient Greek polis or city-state served as the center of Ancient Greek society and civilization. A polis was both a city and a state, which why it is often referred to as a city-state. It holds the status of both because of the self-governing each city contained. The polis included the city itself as well as the countryside land surrounding it. Each polis had a community of citizens that took immense pride in their particular polis and were prepared to defend their ideals and beliefs which caused conflicts among the surrounding city-states, and they were frequently at war with one another. Aristotle believed that a polis was a way to differentiate between Greek civilized individuals and barbarians. Civilization was centered in the polis and the Greek male citizens were at the very center of this. To be a citizen of the polis you must be a Greek male, meaning that women, children, foreigners, and slaves were not citizens. The system of a polis were incredibly sophisticated and they possessed their own armies, laws, political systems, taxation, and often times calendar and currency. In a polis, citizens were very active in the city life and participation in society was incredibly common. In city-states like Athens, there was a vast amount of facilities available to the citizens so that even the poorest of citizens had facilities within the polis. There was a variety of different governmental systems that were present in an Ancient Greek polis, some were monarchies, some were oligarchies, and in Athens there was democracy present where the people ruled. No matter what the ruling government form, more city-states had an assembly. This assembly met regularly and their meetings were held at the Pnyx which was known to hold around 6000 citizens. Speakers would be called up to state certain issues and these issues would be voted upon through the use of white and black pebbles in urns.