From the 5th to the 4th century BCE, Athens's male citizen population of 40,000 people, about a fifth of the total population, practiced direct, participatory self-governance. At a general assembly known as the ecclesia, which met at least 40 times a year, citizens used majority voting to decide on public policy. Athenians referred to their city as a polis, meaning a political community.
On the cusp of a possible revolt against the ruling aristocratic class, Athens in 594 BCE appointed Solon as chief magistrate to maintain peace. Solon's reforms laid the basic groundwork for Athenian democracy. While maintaining a significant role for the aristocratic Areopagus council, Solon revived the ecclesia and granted ordinary citizens the right to participate in it. Starting in 506, the chief magistrate Cleisthenes initiated direct democracy in Athens, establishing local units called demes to take over much of the local governance that family clans had been controlling. Later reformers stripped the Areopagus council of its remaining commanding powers.
Athenian democracy involved a highly exclusionary conception of the polis, and thinkers have long debated the centrality of this exclusivity to the citizenry's democratic governance. While some Anarchists such as Murray Bookchin argued that such exclusivity was harmful or contradictory to direct democracy, the Crimethinc Ex-Workers Collective asserts that exclusion and exploitation are intrinsic features of democracy as opposed to genuine anarchy:
"In ancient Athens, the much-touted 'birthplace of democracy,' we already see the exclusion and coercion that have been essential features of democratic government ever since. Only adult male citizens with military training could vote; women, slaves, debtors, and all who lacked Athenian blood were excluded. At the very most, democracy involved less than a fifth of the population.
Indeed, slavery was more prevalent in ancient Athens than in other Greek city states, and women had fewer rights relative to men. Greater equality among male citizens apparently meant greater solidarity against women and foreigners. The space of participatory politics was a gated community."
According to Wikipedia, 5th-century Athens "produced some of the most influential and enduring cultural artifacts of the Western tradition. The playwrights Aeschylus, Sophocles and Euripides all lived and worked in 5th century BCE Athens, as did the historians Herodotus and Thucydides, the physician Hippocrates, and the philosopher Socrates."
Athenian culture emphasized the theme of citizenship, meaning active participating in a political community. Paideia, normally translated as education, taught residents civic duty, critical thinking, and virtuous living.
Freedom did not extend to women, slaves, and non-citizens. Athens was extremely patriarchal, and women "were expected to wear veils when they ventured out in public." The Crimethinc Ex-Workers Collective points out:
In ancient Athens, the much-touted "birthplace of democracy," we already see the exclusion and coercion that have been essential features of democratic government ever since. Only adult male citizens with military training could vote; women, slaves, debtors, and all who lacked Athenian blood were excluded. At the very most, democracy involved less than a fifth of the population.
Indeed, slavery was more prevalent in ancient Athens than in other Greek city states, and women had fewer rights relative to men. Greater equality among male citizens apparently meant greater solidarity against women and foreigners. The space of participatory politics was a gated community.
Four fifths of the population--women, slaves and foreign residents--were excluded from government. Still, a population of 40,000 Athenian male citizens practiced direct democracy at the local and citywide levels. This section describes Athenian democracy in the fifth century BCE, after Cleisthenes's reforms.
Athenian assemblies used majoritarian decision-making, although political scientist David Helds notes that "the ideal remained consensus, and it is not clear that even a majority of issues was put to the vote." Athens may have been the birthplace of formal majoritarian voting.
Anthropologist David Graeber, a proponent of modified consensus decision-making, speculates that majoritarian voting emerged from the fact that the citizens of Athens were armed. Majority voting, according to Graeber's theory, became a proxy for what would happen if the population actually fought over a given issue: "Every vote was, in a real sense, a conquest."
Cleisthenes divided Athens into over 100 administrative areas known as demes. Each deme made decisions at a general assembly presided over by an elected mayor. The demes elected officials and priests, managed parish lands, maintained shrines, organized festivals, and enacted taxes. A citizen could participate in his deme starting at the age of 18. Membership in demes were hereditary, meaning that a person living away from his deme was disenfranchised. 
The ecclesia, a city-wide general assembly that at its height met at least forty times a year, was the city's legislative body. Any citizen over the age of 20 could attend, vote and speak. For ordinary decisions, there was no quorum. A decree that uniquely affected a single individual required 6,000 people to be present. Banishing someone required a 6,000-person majority. Average attendance was probably below 5,000. The only recorded vote shows 3,461 voting yes and 155 voting no. The Council of Five Hundred, composed of people selected by lot to serve one-year terms, created an agenda for each ecclesia meeting and circulated it along with the meeting announcement. Alfred Zimmern describes the atmosphere on Pnyx Hill before the start of the assembly:
The Athenian assembly came together in the open air, and yet not, for all that, under conditions of physical discomfort: for the orators of Athens did not compel their victims, like our park and street-corner gatherings to listen standing up. The Athenians came to their popular assembly unlike the Romans, in order to think, not to gape; and no man (except for a Socrates) can think hard standing upright for hours. On an assembly morning citizens would come together soon after sunrise, having left their beds in the country, or in Salamis across the water, long before it was light enough to see their way into their cloak and shoes. Once safely on Pnyx Hill they would dispose themselves as they liked among friends and acquaintances; for Demos in Council knew of no tribes or thirds or any subdivisions of his sovereignty. There they would sit grumbling and yawning and scratching their heads, going over their olive-trees or composing letters to absent friends, wishing they had stopped for a mixed drink on their way up, above all lamenting the square meal they will not get till tomorrow (for it will be too late when they get home to have a supper worth eating), till the lazy townfolk stroll up from Athens and the Piraeus and, last of all, the unpunctual councilors come bustling through the crowd. Then, at last, when our countryman has not a curse left in his quiver, prayers are announced, and the proceedings begin." 
Council of Five Hundred
The Council of Five Hundred handled administrative tasks, including finance and foreign affairs. Notably, the council created the agenda for each ecclesia meeting. Members were drawn by lot from the set of candidates elected by the demes. Members served for only one year, and a citizen could not serve more than twice. The council was divided into ten committees, each of which was on duty for one tenth of the year.
Areopagus and Archons
Athens' democratic features existed alongside an areopagus council, which the assembly elected from among the aristocracy, and magistrates known as archons. In 487 BCE, election by lot was introduced for the archons. In 461 BCE, the areopagus council's powers were transferred to the ecclesia, the Council of Five Hundred, and the jury courts. 
Although the city placed few restrictions on Athenians' private property and avoided taxation when possible, citizens were expected to generously contribute funds for public works. Zimmern explains the attitude toward taxes, "To talk of taxes in such an atmosphere is a blunder as well as a sacrilege, for a tax is a payment which leaves a man poorer: a 'liturgy' leaves him richer. He still possesses what he has given, and yet added to the common store." Zimmern argues socialism would not have worked for the Athenians: "It was not that they objected to working in a State system: it was that they objected to working in any system whatsoever. It was their settled inclination and proudest boasts to remain amateurs". 
Takis Fotopoulos, in contrast, argues that Athenian direct democracy collapsed precisely because of Athenians' failure to combine it with a system approaching libertarian socialism. Slavery allowed some citizens to get significantly richer than other citizens, and it was the wealthier class that had more time to spend on issues of governance. By freeing the slaves and expropriating the rich, Fotopoulos argues, Athens could have relied on internal rather than external sources of revenue to meet its citizens needs. Instead, Athens' reliance on external revenues meant that the city's military decline, beginning with its defeat in the Peloponnesian War, led to an economic decline as well.
In other words, given that Athens was no longer in a position to impose any more external taxes which would finance its internal economic democracy, the precondition for the continuation of political democracy was its universalization so as to include all the city residents (free citizens, women, slaves) and the further development of economic democracy. This democracy would not be based, as before, on the external financing of the huge public expenditures, but on the drastic reduction of the economic inequality amongst residents, through the heavier taxing of the higher strata and the parallel abolition of slavery which functioned as a disincentive for productive work.
C.L.R. James also argues that slavery was ultimately harmful to Athenian democracy:
There are many people today and some of them radicals and revolutionaries who sneer at the fact that this democracy was based on slavery. So it was, though we have found that those who are prone to attack Greek Democracy on behalf of slavery are not so much interested in defending the slaves as they are in attacking the democracy. Frederick Engels in his book on the family makes an analysis of slavery in relation to Greek Democracy and modern scholars on the whole agree with him. In the early days, Greek slavery did not occupy a very prominent place in the social life and economy of Greece. The slave was for the most part a household slave. Later, the slaves grew in number until they were at least as many as the number of citizens.
In later years, slavery developed to such a degree, with the development of commerce, industry, etc., that it degraded free labor. And it is to this extraordinary growth of slavery and the consequent degradation of free labor that Engels attributes the decline of the great Greek Democracy.
The historian Clive Pointing argues that by the 5th century Athens already faced severe soil erosion and deforestation due to overgrazing: "Although the Greeks were well aware of techniques for preserving soil such as manuring to maintain the structure of the soil and terracing to limit the erosion on hillsides, the pressure from a continually rising population proved too great. The hills of Attica were stripped bare of trees within a couple of generations and by 590 in Athens the great reformer of the constitution, Solon, was arguing that cultivation on steep slopes should be banned because of the amount of soil being lost."
Anarchist writer Murray Bookchin points out that the Greeks' philosophy tended to foster a fear of wild nature and a desire to systematically domesticate the wild.
Perhaps Athens's ecological legacy was not all negative, however. Bookchin comments, "Even the ancient Greeks, heirs to a thin, mountainous forest soil that suffered heavily from erosion, shrewdly reclaimed much of their arable land by turning to orchardry and viticulture." In perhaps the first essay ever combining modern ecology with anarchism, Bookchin advocated a decentralized, face-to-face politics modelled on the Athenian polis, "partly to solve our pollution and transportation problems, partly also to create real communities".
Each year, the demes elected a total of 6,000 jurors to serve in the central court system. Each morning, the jurors would present themselves at Theseus's temple and see if they were chosen by lot to serve that day. Each court had a minimum of 201 jurors, in order to prevent corruption.
Bookchin argues that because the jurors were not a permanent, professional class, "the ‘state’ as we know it in modern times could hardly be said to exist among the Greeks”. Bookchin defines the state as a professional apparatus of bureaucratic control. Bob Black, asserting that Athens did have a state, mocks Bookchin, ""Just ask Socrates. What’ll you be having? Hemlock, straight up." This remark referenced the infamous 399 BCE trial sentencing Socrates to death by ingestion of the poisonous plant, as a penalty for impiety and corrupting the youth.
Athens had a conscript army, with ten elected generals called strategos. The city headed a small empire, which fought and lost to the Spartans in the 431-404 Peloponnesian War. The Spartans installed the oligarchical Thirty Tyrants over Athens, although Athenians removed the tyrants in a 403 battle at Piraeus and began restoring its democracy. In 338, Macadeonia's King Phillip defeated Athens in the Battle of Chaeoronea, effectively subjecting Athens to Macedonian control. In 322, Macedonian general Antipater suppressed Athenian democracy and imposed oligarchical government on the city.
- Alfred Zimmern, The Greek Commonwealth: Politics and Economics in Fifth-Century Athens (New York: The Modern Library, 1956). Janet Biehl, The Politics of Social Ecology: Libertarian Municipalism. John A. Rothchild, "Introduction to Athenian Democracy of the Fifth and Fourth Centuries BCE," http://homepages.gac.edu/~arosenth/265/Athenian_Democracy.pdf.
- Crimethinc, "From Democracy to Freedom," 2016, https://crimethinc.com/2012/04/29/feature-from-democracy-to-freedom.
- Murray Bookchin. The Rise of Urbanization and the Decline of Citizenship (San Francisco: Sierra Club Books, 1987). 59.
- David Graeber, Debt: The First 5,000 Years (New York: Melville House, 2011), 188.
- "From Democracy to Freedom," Crimethinc Ex-Workers Collective, 29 April 2016, https://crimethinc.com/2016/04/29/feature-from-democracy-to-freedom.
- David Held, Models of Democracy, Third Edition (Stanford: Stanford University Press, 2006), 17.
- David Graeber, Fragments of An Anarchist Anthropology (Chicago: Prickly Paradigm Press, 2004), 90.
- Alfred Zimmernm The Greek Commonwealth: Politics and Economics in Fifth-Century Athens (New York: The Modern Library, 1956), 153-156.
- Zimmern, The Greek Commonwealth, 167-171.
- Alfred Zimmern, The Greek Commonwealth, 162-164.
- Takis Fotopoulos, "Direct and Economic Democracy in Ancient Athens and its Significance Today", Democracy & Nature, Vol. 1, No. 1 (1992). http://www.democracynature.org/vol1/fotopoulos_athens.htm
- Zimmern. The Greek Commonwealth. 294, 299.
- Fotopoulos, "Direct and Economic Democracy in Ancient Athens and its Significance Today".
- James, C.L.R., "Every Cook Can Govern," Correspondence, Vol. 2, No. 12. June 1956, https://www.marxists.org/archive/james-clr/works/1956/06/every-cook.htm/.
- Clive Pointing, A New Green History of the World (London: Penguin Books), 75.
- Murray Bookchin, The Ecology of Freedom: The Emergence and Dissolution of Hierarchy (Palo Alto: Cheshire Books, 1982), 109.
- Murray Bookchin. "Towards a Liberatory Technology," 1965, http://dwardmac.pitzer.edu/anarchist_archives/bookchin/tolibtechpart2.html.
- Murray Bookchin, "Ecology and Revolutionary Thought," 1964, http://dwardmac.pitzer.edu/Anarchist_Archives/bookchin/ecologyandrev.html.
- Bookchin. The Rise of Urbanization and the Decline of Citizenship, 33-34.
- Bob Black, Anarchy After Leftism, http://theanarchistlibrary.org/library/bob-black-anarchy-after-leftism
- John A. Rothchild, "Introduction to Athenian Democracy of the Fifth and Fourth Centuries BCE.", http://homepages.gac.edu/~arosenth/265/Athenian_Democracy.pdf; "Thirty Tyrants," Encyclopedia Britannica, http://www.britannica.com/EBchecked/topic/592610/Thirty-Tyrants