|Louis-Michel van Loo|
During the 1740s and early 1750s there were no closer friends and collaborators in all of Paris than Jean-Jacques Rousseau (1712-1778) and his exact contemporary Denis Diderot (1713-1784). They abetted each other fruitfully in the mid-century endeavor to promote radical new ideas within an atmosphere of aggressive state censorship. A few years after their deaths, when the French Revolution occurred, both writers were posthumously canonized as prophet-saints of the brave new world and remained linked together in the popular mind. This in spite of the fact that in 1757 disagreements over philosophical outlook and personal conduct caused them to break off the connection permanently. Their bitter mutual reproaches appeared mainly in print, and contemporary fascination with the quarrel confirmed their rock-star status.
In the most thorough biography of Diderot yet written (even though it is a very clumsy book) the mid-20th-century American scholar Arthur M. Wilson described the social paradox created by the friction between Diderot and Rousseau – "That an incident in the private lives of two middle-class writers could absorb the interest of the aristocratic society of the ancien régime to such a degree is a symbol of the revolution occurring in the French outlook. The Marquis de Castries, a nobleman destined to be a marshal of France, impatiently remarked one day when the quarrel of Diderot and Rousseau had become public knowledge, "It's incredible. People don't talk of anything but of these fellows. Persons without an establishment, who don't have a house, who are lodged in a garret. One just can't get used to all that."