Answer:
Democracy in Athens might have been the most clear example of a true democracy. At least between the 4th and 5th centuries BC. Although initially jurors came from the elite of Athens, this was changed later on, and a jury could be comprised by a minimum of 200 jurors, to the largest one in existence, known as the Heliaia, which was comprised of 6000 people. These jurors, after the reforms of Solon in 594 BC, began to be elected by lot, and the election was open to all members of the four social classes existing in Athens at the time (theoretically, as later on it was deemed that those who could afford an armor and be part of the military could be elected jurors), regardless of their economic status. Also, these jurors would last for periods of a year.
The advantage of this system of election, and also the number of people who could participate in the system is that decisions could be said to be taken by the people, and that the people actually had a say in the matter. Also, all social classes were essentially represented, and the sheer numbers that could be elected further ensured that this were so.
However, on the downside, the actual decision making process could be hampered simply because making 6000 people agree on a simple matter, could be a real challenge. It also was a challenge to choose who would lead such a large group, who would be the one to organize such a large crowd to finally reach the goal of making actual choices.
Another disadvantage was that these large numbers could only be reached by opening up spots for all social classes and the lower ones were not necessarily educated and prepared to make decisions that would benefit all. So, in the end, these gatherings might end up becoming more large dicussions between disgreeing members, than a true process of decision-making.
