Why was a Council of 500 necessary in early Greece?

Answer 1

Greece did not have a council of 500 - the Greek world comprised over 2,000 independent city-states each with its own government.

The Council of 500 was part of the democratic system introduced in the city-state of Athens in the later 5th Century BCE. Under the radical democracy, the citizens (adult males) met in fortnightly assembly and made all the decisions. Between meetings, those decisions had to be implemented, so the council was established to do that, and deal with any problems which arose before the next Assembly meeting.

The 500 members of the council was necessary for two reasons: 50 were on duty at any time, 24 hours a day to deal with problems which might arise, so the 500 allowed for 10 shifts. And the reason that 50 were required for a shift is because the Council members were selected by lot from the adult male population and this ensured a mix of members ranging from the dumbest to the smartest. The numbers ensured that there were always some smart people in their ranks who could be relied on to make sensible decisions.

This was a characteristic of the system. Ten members were allotted to collecting the daily handling of public funds to ensure that at least a couple could count properly, and so on through the whole administration system. 500 jurors were usual in a court case to ensure there was intelligent consideration. The exception was the 10 generals - they were elected specifically, as the citizens, who made up the army and navy, didn't want to risk their lives being led in battle by some dummo whose name was drawn out of a hat. And when an important political decision was made in the Assembly it usually had the rider 'the generals to implement' even if it was not a military matter.

Answer 2

In order to introduce a wide range of citizens to overcome the attempts by the oligarchs to reclaim power after the tyrants were expelled.