While the age of science has cast a shadow over the accomplishments of the ancient Greeks, their records reflect an apparently unique social circumstance. The society of pre-Hellenic Greece underwent the consolidation of towns into cities in a culture that was sophisticated enough to manage the process, and literate enough to document it. Furthermore, the temperateness and fertility of the Greek ecology allowed time for leaders and citizens alike to invest in personal excellence, rather than remaining focused narrowly on day-to-day survival.
The Greeks were intensely aware of the need to match social structures to the character of a people. The leaders of the city-states argued political philosophy with the conviction of people who could imagine no other way to live. In fact, they probably could not. The character of the Spartan (Athenian, Thebe) was functional only within the Spartan (Athenian, Theban) milieu. Unfortunately, the argument of their convictions was often taken to the battlefield. Ultimately, it was their inability to harmonize their politics in a larger association that led the experiment away from Greece into foreign hands. The transfer of the liberalizing impetus of Greek politics though the foremost student of Aristotle, Alexander of Macedon, is a fascinating story.
The vitality of the struggles between the Greek city-states reflected the power of social coherency manifested in the polis. The Greeks recognized the spiritual aspect of that coherency. It was a technology used on the battlefield, and pursued by a political elite that eventually descended to despotism. The failure of the Greeks was their inability to factor their diverse experience as insights that led to evolution of robust and flexible systems for political change. Those systems were developed relatively recently in the modern democracies. In ancient Greece, conversely, the only effective check on privilege was the personal nobility of the elite.
The Greeks did make forays in this regard. The cultural leaders attempted to simplify the religious pantheon, emphasizing the deities as guiding spirits rather than as avatars of human potential - and caprice. Plato documented the attempts of Socrates to moderate the ignoble or misguided impulses of the political elite, and Aristotle carried that work forward.
Socrates observed that the polis appeared to lose its coherency when the population of a city surpassed 100,000, and perhaps that explains the descent of the Greek city-states into tyranny. Throughout the 19th and 20th centuries, Western cultures struggled with the attempt to break up cultural cliques to create more homogeneous and egalitarian societies. Unfortunately, the mechanism of change has often been martial force or punitive legislation that forced concessions from the privileged. While arguably necessary, this has had the side-effect of disrupting social consensus while creating logistical barriers to its evolution. Socrates' rule of 100,000 may figure in those difficulties: if coherency cannot be sustained, a reasonable response is the application of ethics to control social evolution.
The beginning of the 21st century has seen a counteraction in America. Sub-cultures are re-segregating, perhaps in an intuitive attempt to re-establish coherency. The goal of the over-arching political elite must be to recognize greatness in each sub-culture, and to facilitate association between leaders, particularly where ties would be mutually beneficial. Conscious facilitation of the dynamic of love between sub-cultures is the way out of the snare of the Ancient Greeks.