Mercier's L'An 2440, rêve s'il en fut jamais (literally, "The Year 2440: A Dream If Ever There Was One"; translated into English as Memoirs of the Year Two Thousand Five Hundred [sic]; and into German as Das Jahr zwey tausend vier hundert und vierzig: Ein Traum aller Träume) is a utopian novel set in the year 2440.
An extremely popular work (it went through twenty-five editions after its first appearance in 1770), the work describes the adventures of an unnamed man, who, after engaging in a heated discussion with a philosopher friend about the injustices of Paris, falls asleep and finds himself in a Paris of the future.
 Darnton writes that "despite its self-proclaimed character of fantasy...L'An 2440 demanded to be read as a serious guidebook to the future.
It offered an astonishing new perspective: the future as a fait accompli and the present as a distant past.
Who could resist the temptation to participate in such a thought experiment?
 And once engaged in it, who could fail to see that it exposed the rottenness of the society before his eyes, the Paris of the eighteenth century?"

Mercier's hero notes everything that catches his fancy in this futuristic Paris.
Public space and the justice system have been reorganized.
Its citizens' garb is comfortable and practical.
Hospitals are effective and based on science.
There are no monks, priests, prostitutes, beggars, dancing masters (i.e. teachers), pastry chefs, standing armies, slavery, arbitrary arrest, taxes, guilds, foreign trade, coffee, tea or tobacco and all useless and immoral previously-written literature has been destroyed.

Mercier's future is not wholly utopian.
 The extremes of wealth and poverty have been abolished; nevertheless, the poor still exist.
There is little economic development and the population of France has increased only by 50%.
Mercier's L'An 2440, rêve s'il en fut jamais (literally, "The Year 2440: A Dream If Ever There Was One"; translated into English as Memoirs of the Year Two Thousand Five Hundred [sic]; and into German as Das Jahr zwey tausend vier hundert und vierzig: Ein Traum aller Träume) is a utopian novel set in the year 2440. An extremely popular work (it went through twenty-five editions after its first appearance in 1770), the work describes the adventures of an unnamed man, who, after engaging in a heated discussion with a philosopher friend about the injustices of Paris, falls asleep and finds himself in a Paris of the future.  Darnton writes that "despite its self-proclaimed character of fantasy...L'An 2440 demanded to be read as a serious guidebook to the future. It offered an astonishing new perspective: the future as a fait accompli and the present as a distant past. Who could resist the temptation to participate in such a thought experiment?  And once engaged in it, who could fail to see that it exposed the rottenness of the society before his eyes, the Paris of the eighteenth century?"
Mercier's hero notes everything that catches his fancy in this futuristic Paris. Public space and the justice system have been reorganized. Its citizens' garb is comfortable and practical. Hospitals are effective and based on science. There are no monks, priests, prostitutes, beggars, dancing masters (i.e. teachers), pastry chefs, standing armies, slavery, arbitrary arrest, taxes, guilds, foreign trade, coffee, tea or tobacco and all useless and immoral previously-written literature has been destroyed.
Mercier's future is not wholly utopian.  The extremes of wealth and poverty have been abolished; nevertheless, the poor still exist. There is little economic development and the population of France has increased only by 50%.
Louis-Sébastien Mercier