“In my way home I ‘light and to the Coffee-house, where I heard Lt. Coll. Baron tell very good stories of his travels over the high hills in Asia above the clouds…” Samuel Pepys 
The first coffeehouses appeared in London in the late 17th century, after the restoration of Charles II in the wake up the English Civil War. By 1675, there were at least 3,000 of them.  The coffeehouses were open to anyone who could pay a penny for a cup of coffee, whether rich or poor, noble or common. In that respect they were like Ale Houses, with the difference that people did not consume alcohol in them, but stayed sober. This enabled them to become places for serious critical discussion, where social etiquette made it acceptable to strike up conversations with anyone who happened to be around. They were also places to catch up on the news, and even served as postal addresses for regular clients who would pop in several times a day. Many coffeehouses also issued their own token money.
Coffee in the 17th century tasted foul, but acted as a mental stimulant which facilitated social interaction and the flow of ideas between people. People went to the coffeehouses because they wanted the unique social and intellectual atmosphere they provided. The coffeehouse scene was frequented by common folk and learned men, who related to each other as equals, or tried to. Samuel Pepys makes frequent references to his trips to the Coffee-house, where he would catch up with friends and listen to their stories.  Isaac Newton was spurred by his coffeehouse debates to write Principia Mathematica.  They were hotbeds of creative and intellectual ferment, accessible for the price of a coffee, colloquially known as the “penny universities.”
The Birth of the Public Sphere
The coffeehouse scene in 17th century London had a counterpart in Paris in the salons, but they worked differently. A salon typically had a hostess, called a salonniere, an aristocratic woman who kept the rabble out, and used her social instincts to facilitate conversation between frequenters, who were exclusively male.  People in the salons were more polite and talked over each other less, but London’s coffeehouses were livelier and more egalitarian. However, they too excluded women from any meaningful participation, reflecting the common prejudice of the day that women were less capable of critical debate than men. Despite this, both the coffeehouses and salons were instrumental to the spread of progressive Enlightenment ideas and values, by constituting what Jurgen Habermas called a public sphere: a public place in which people met as private individuals to critically debate matters that concerned them. 
In the Age of Enlightenment, it soon became the norm that affairs of state could be discussed by private individuals, who were free to scrutinise and hold their governments to account however they liked. This was helped by a plethora of newspapers and periodicals, whose production was intimately connected to the coffeehouse scene. Papers reported news, gossip and ideas that were circulating, connecting them together in a kind of 17th century form of social media.  Coffeehouses became known by the type of conversation you could find there; Will’s coffeehouse gained a reputation, for example, as a favourite haunt for young writers. The Tatler, an English literary and society magazine founded in 1709, used the names of coffeehouses as topic headings.
Unsurprisingly, the coffeehouses were hated by Charles II, whose father was beheaded in the civil war not long before. He tried in vain to suppress these “places where the disaffected met, and spread scandalous reports concerning the conduct of His Majesty and His Ministers.”  In Versailles, the burgeoning salons scene around the palace became a favourite place for disaffected bourgeois to hatch plots and ferment radical ideas, much to the horror of Louis XVI. In 1789, Camille Desmoulins stood on a table at the Café de Foy and is said to have launched the French revolution by screaming “Aux armes, citoyens!” to an angry mob. 
Modern day coffeehouses
Today coffee tastes better but cafés are different kinds of places. Strangers do not typically engage in serious conversation with each other, although they sometimes nod, smile or stand aside for each other. These small social graces are perhaps all that is left from a more interesting time. Habermas argued that the public sphere has all but collapsed into an empty spectacle, created through mass media and confining critical debate to a narrow elite whose opinions stay within acceptable bounds. Perhaps this is a little exaggerated, but the old coffeehouses stand as a lively example of what engaged public critical debate can be like, and what kind of large scale social consequences it can have.  To the coffeehouse!
 Samuel Pepys, Diary, February 1664
 Coffeehouses, Wikipedia
 See 
 Tom Standage, Social Networking in the 1600s, The New York Times
 Bonnie calhoun, Shaping the Public Sphere: English Coffeehouses and French Salons and the Age of Enlightenment, Colgate Academic Review
 Jurgen Habermas, Structural Transformations of the Public Sphere, The MIT Press
 See 
 Fraser Nelson, The Original Coffeehouse, The Spectator
 Cafe de Foy, Wikipedia
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