How brave a thing is freedom of speech, which has made the Athenians so far exceed every other state of Hellas in greatness!
The word used is isegoria ("equality of speech"), which did not mean the same as the modern concept of free speech but was perhaps the first step towards it. Isegoria meant the equal right to address the ecclesia (the legislative assembly). A closer approximation of the modern usage, though still not exact, is parrhesia. Though the Athenians might not have entirely understood what freedom of speech meant, de facto the scope of that freedom in the city was the greatest ever achieved up to that point anywhere (despite some violations like the trial of Socrates), although compared with later periods it was very restricted. It is this unprecedented liberty of speech (not democracy, which is rather the opposite of free speech!) that elevated Athens to the position of the world's cultural, scientific and philosophical capital. We owe our entire civilization to the fact that, for the first time in history, the human mind, the engine that drives the world, was relatively free to create. This Athenian spirit was espoused by Thomas Jefferson, who (among other Founding Fathers) made free speech one of the fundamental pillars of the American polity:
I have sworn upon the alter of God eternal hostility against every form of tyranny over the mind of man.
While providing a "spiritual" foundation for creative achievement, the Athenians failed to create a "material" framework for an advanced industrial society. While the mind was relatively free, the hands were shackled. Property was insecure, and courts were political tools used by the poor to rob the rich (ominous parallels, eh?):
We find in Xenophon's Banquet a very lively description of a republic in which the people abused their equality. Each guest gives in his turn the reason why he is satisfied. "Content I am," says Chamides, "because of my poverty. When I was rich, I was obliged to pay my court to informers, knowing I was more liable to be hurt by them than capable of doing them harm. The republic constantly demanded some new tax of me; and I could not decline paying. Since I have grown poor, I have acquired authority; nobody threatens me; I rather threaten others. I can go or stay where I please. The rich already rise from their seats and give me the way. I am a king, I was before a slave: I paid taxes to the republic, now it maintains me: I am no longer afraid of losing: but I hope to acquire."
Montesquieu, the Spirit of the Laws
For the Athenians, liberty (eleutheria) was a positive, not negative, liberty - freedom to govern, not freedom from government. It was a pernicious concept connected with democratia (the power of the people) and isocratia (equality of power). It is no wonder that the leading Greek philosophers were against such freedom. Seeing the disastrous results of democracy, Plato advocated the other extreme - what we would call a totalitarian government governed by philosopher kings.
The first theoretical glimpse of a truly free society was perhaps the Athenian concept of isonomia - equality before the law. It is said to have been established by Solon but it seems that it was never effectively implemented in practice. This inspired Aristotle's formulation of the rule of law and laid the foundation of Roman constitutionalism. Entrenching the rule of law and the security of private property, Rome moved much farther in the direction of "material" freedom.
Though they might have vaguely glimpsed the nature of free speech, neither the Greeks nor the Romans extended the principle of negative liberty to the entire realm of human activity. This was done by the United Kingdom and the United States in the 18th through 19th centuries. As a result, such an enormous amount of energy was released that it transformed the world faster than ever before and brought an age unbelievably futuristic compared with any previous era. A bizarre ode to capitalism can be found, of all people, in Marx's Communist Manifesto, which somewhat belies its message.
Meantime the markets kept ever growing, the demand ever rising. Even manufacturer no longer sufficed. Thereupon, steam and machinery revolutionised industrial production. The place of manufacture was taken by the giant, Modern Industry; the place of the industrial middle class by industrial millionaires, the leaders of the whole industrial armies, the modern bourgeois.
Modern industry has established the world market, for which the discovery of America paved the way. This market has given an immense development to commerce, to navigation, to communication by land. This development has, in its turn, reacted on the extension of industry; and in proportion as industry, commerce, navigation, railways extended, in the same proportion the bourgeoisie developed, increased its capital, and pushed into the background every class handed down from the Middle Ages. (…)
The bourgeoisie has disclosed how it came to pass that the brutal display of vigour in the Middle Ages, which reactionaries so much admire, found its fitting complement in the most slothful indolence. It has been the first to show what man’s activity can bring about. It has accomplished wonders far surpassing Egyptian pyramids, Roman aqueducts, and Gothic cathedrals; it has conducted expeditions that put in the shade all former Exoduses of nations and crusades.
The bourgeoisie cannot exist without constantly revolutionising the instruments of production, and thereby the relations of production, and with them the whole relations of society. Conservation of the old modes of production in unaltered form, was, on the contrary, the first condition of existence for all earlier industrial classes. (…)
The need of a constantly expanding market for its products chases the bourgeoisie over the entire surface of the globe. It must nestle everywhere, settle everywhere, establish connexions everywhere.
The bourgeoisie has through its exploitation of the world market given a cosmopolitan character to production and consumption in every country. To the great chagrin of Reactionists, it has drawn from under the feet of industry the national ground on which it stood. (…) The intellectual creations of individual nations become common property. National one-sidedness and narrow-mindedness become more and more impossible, and from the numerous national and local literatures, there arises a world literature.
The bourgeoisie, by the rapid improvement of all instruments of production, by the immensely facilitated means of communication, draws all, even the most barbarian, nations into civilisation. (…) The bourgeoisie has subjected the country to the rule of the towns. It has created enormous cities, has greatly increased the urban population as compared with the rural, and has thus rescued a considerable part of the population from the idiocy of rural life. (…) The bourgeoisie, during its rule of scarce one hundred years, has created more massive and more colossal productive forces than have all preceding generations together. Subjection of Nature’s forces to man, machinery, application of chemistry to industry and agriculture, steam-navigation, railways, electric telegraphs, clearing of whole continents for cultivation, canalisation of rivers, whole populations conjured out of the ground — what earlier century had even a presentiment that such productive forces slumbered in the lap of social labour?