The classical definition
The ancient Greek term dēmokratia — dēmos-kratos, power of the people — names a specific working constitutional form in which authority belongs to the citizen body and is exercised by the citizen body through institutional procedures the constitution makes available. The form is older than the term; the term is established by the fifth century BCE. Both terms are Greek; both substrates are classical.
The working ancient democracy was direct, participatory, and unmediated by what modern constitutional theory would call representation. The Athenian Ekklēsia met approximately forty times a year on the Pnyx; the citizens present voted on the assembly's business directly; the Boulē that prepared the agenda was rotated by lot through the citizen body yearly; the popular juries decided cases of major political consequence. Citizens were not represented; citizens participated.
The ancient defence
The principal classical defence of democracy as a political form is Pericles's Funeral Oration as Thucydides reconstructs it in Peloponnesian War II.36–46. The argument runs: the city is great because its citizens are free; its citizens are free because the constitutional form permits and requires their participation; the constitutional form permits this because the city, in turn, trusts its citizens to act for it. The defence is not abstract — Pericles is making it during the working operation of the city, in front of citizens who can refuse it.
The Periclean defence is the working ancient case for what democratic participation produces — public confidence, intellectual openness, willingness to take long views — when the conditions for the participation are present. The defence is also, in Thucydides's framing, conditional on those conditions remaining present.
The ancient critique
The ancient critiques of democracy are more numerous and on the whole more sustained than the defences. Three principal strands.
Plato in the Republic Book VIII reads democracy as the political form that produces, by its own internal logic, the tyrannical individual and the tyrannical regime. The argument is psychological-political: a constitution that treats all desires as equally legitimate will produce souls that treat their own desires as equally legitimate, and a soul of that sort under unbounded political conditions is the tyrannical soul. Whether Plato was right about the dynamic is a matter the European tradition has continued to argue. That he stated it sharply enough to be still argued is the point.
Aristotle in the Politics reads democracy as the corrupt form of politeia — the constitution of the many ruling in their own interest rather than in the common interest. The good form (rule of the many in the common interest) Aristotle calls politeia without further specification; the corrupt form he calls democracy. The classical Aristotelian taxonomy is the source for the medieval and early-modern European reading of democracy as a deficient political form. The modern political tradition recovers democracy as a positive constitutional ideal only much later.
Thucydides records, without making the philosophical case in the abstract, the working operation of Athenian democracy under wartime stress — the Mytilenean debate, the Melian dialogue, the Sicilian expedition. The narrative is the working critique: democratic decision-making produces the catastrophic decisions Thucydides records as well as the considered decisions Pericles defends. Both are characteristic of the form.
The long European inheritance
The medieval European tradition mostly treated democratia as a deficient constitutional form (following Aristotle). The classical-republican tradition that emerges in the Italian city-states from the twelfth century onward and runs through the English commonwealth writers, the French revolutionary tradition and the American founding rehabilitates the form gradually — not as the Athenian direct democracy (which all of these traditions read as unsuitable for the scale of the modern state) but as representative democracy, a constitutional adaptation that preserves popular sovereignty under conditions where direct participation is logistically impossible.
The modern constitutional democracy is therefore not the ancient democracy but a working adaptation that the European tradition spent two and a half thousand years arriving at, across criticism, defence, and the practical experiment of the long classical inheritance.
Why the platform reads it
The platform reads democracy because the form is the most sustained ancient experiment in self-government conducted in public, and because the European tradition has spent the time since the ancient experiment thinking through what the experiment showed. The reading is not partisan. The constitutional form produced the Athenian achievements; it also produced the Athenian failures; both belong to the careful reading.