Athens and Sparta, the two superpowers of the Hellas, had several similarities which were the foundation for radically different societies.
Athens and Sparta were both centered around a polis and had similar social structures. The polis was a city built around a citadel (acropolis) surrounded by an agricultural area large enough to support the entire population. As small sovereign units, the bonds between the citizen and state (as dictated by law) were more basic than personal ties. They had 4 social classes: free native-born male citizens, Metics(Athens)/Priokoi(Sparta) aka free-born non-citizens, chattel property aka slaves and citizen women (citizen women were essentially chattel property in Athens, although Sparta gave women considerable responsibility, education and training).
Sparta was initially culturally and artistically active, yet it quickly became radically isolationist and militaristic. Sparta was at one point a creative hub, yet when it overtook its western neighbors--the Messenians--it changed dramatically to keep the Messenians as slaves (aka helots). Since there were 10 times as many helots as there were Spartans, a strong military force was needed to keep the helots oppressed. This began Spartan militarism, although it still remained culturally and artistically important. Following the Messenian conquest the Spartans dispatched malcontents to Southern Italy to found Tarentum: this was the only colony they ever sent out. Intellectual horizons were darkened due to a lack of contact with the outside world. However, this was just the beginning of Sparta's severe mentality. When the helots staged a revolt, the Spartans were terrified and from thereon enacted an even more radical constitution. Although no laws were written and the entire civilization was constructed upon traditions which lasted until Sparta's downfall, these traditions were deeply imprinted onto new generations and thereby were obeyed innately. There was no cultural nor artistic development at this point, and the sole creative outlet was via theater. It was an oligarchal constitution ruled by a small group of aristocrats tempered by a bit of democracy. It was a military state to its very core.
Although Sparta's transformation resulted in the strongest military of the era, it also stifled creative development and resulted in a decreasing population. Although Sparta valued the beauty of the human body, it was also very violent and killed those who were not sufficient to further Sparta's mentality. In addition, until the age of 30 men could not live with their families. This meant that when men were at their sexual peak they were not allowed to conceive children without sneaking out of their barracks to spend a few hours with their wives at night. As a result, Sparta constantly faced a waning population.
Athens became the first democracy. It began as many villages and a polis caled Athens. The polis' king united the villages such that they became known as Athenians. Eventually, though, an aristocracy prevailed. The leading families were wealty from wine and oil crops, while the commoners were given small plots of land. As the commoners began to sink into debt they resorted into selling themselves into slavery. To help alleviate this suffering, a tyrrany was installed by a high-ranking aristocrat. He used violent means to isolate conspirators, but they fled to a mountain. Upon their decent, on conditions of peace, they slaughtered the tyrant. This resulted in further mistrust of aristocrats among the masses. Draco was commissioned to write a law code, but it was exceedingly harsh and operated in favor of land owners. Narrowly escaping civil war, Athens handed power over to Solomon, who became a hospitable tyrant. He cancelled debts and repatriated many citizens who had been exiled or shipped away to be slaves. He also put in place a new social system which organized citizens by wealth. This resulted in another prison of poverty.
This time, another leader (Peisistratidae) executed numerous aristocrats due to his excessive paranoia. This weakened the aristocracy. Peisisratidae's offspring continued their fathers legacy, but were assassinated. However, the masses had prospered under Peisratidaean rule and to maintain this growth Cleisthenes installed what could be considered the first democracy. By mixing all the individual cliques, he made sure that an individual interest did not overwhelm the success of Athenian civilization. By stripping old political entities of their power, they gradually faded away under Cleisthenes' rule without any violence. Through several minor modifications, including the ostracism, Athens became truly democratic.
This led to corruption, though, as aristocrats again tried to gain power; in addition, it was hotly contested by philosophers with superiority complexes. Democracy did, however, foster tremendous scientific and artistic growth.