Denis Diderot (1713 - 1784) is best known as editor and frequent contributor to the Encyclopédie that defined many of the goals and ideas of the French Enlightenment. He wrote novels as well, but they're very strange -- elliptical, digressive, and satirical dialogues that hover somewhere between fictional fantasies and philosophical tracts. Consequently, it's hard to get a grasp on the main thrust of his ideas.
Andrew S. Curran's recent book Diderot and the Art of Thinking Freely is a big help. This is a wonderful introduction to Diderot's life, work, ideas, and influence. It is ostensibly a biography, but less than half the book is a chronological narrative. The larger chunk is thematically arranged (virtue, art, sex, love, politics) and provides deep dives into his most famous books and some more obscure writings. These discussions are vital for understanding Diderot's intentions and methods. (In pronouncing Diderot's name, the s and t are silent, and the two i's are rendered in English as long e's.)
After spending several months in prison for publishing an atheist tract, Diderot became more careful. He wrote for posterity by keeping many of his writings hidden to be published only after his death. “One only communicates with force from the bottom of the grave,” he said (pg. 177) The Encyclopédie also became quite controversial. It was subjected to halts and bans during the two decades of its creation, and Curran helps us understand why: It “was not the book's anthropocentrism or even its anticlericalism, but the unmistakable tendency to define the Enlightenment project as diametrically opposed to traditional religion in general.” (p. 135)
I was surprised to find myself quite interested in the two chapters on Diderot's politics. After Catherine the Great came to power in Russia in 1762, she initiated contact with Diderot, who became a kind of cultural attaché for her. It was Diderot who arranged the sale of 500 paintings to Catherine that became the core collection of the Hermitage. When he visited Catherine in St. Petersburg and attempted to persuade her to implement liberalizing reforms, Diderot became disillusioned with the possibility of even an intelligent and enlightened despot like Catherine making any substantive changes. “There is no sovereign except the nation” he later said, “there can be no true legislator except the people” (pg. 349).
It was in anonymous contributions to Guillaume-Thomas Raynal's Philosophical and Political History of the Two Indies where Diderot honed his evolving political ideas, including attacks on "what he believed to be his era's most glaring evil: the ongoing business of African chattel slavery." (pg. 365) It's even possible that Diderot's predictions of a “Black Spartacus” who would lead a revolt of slaves inspired Toussaint Louverture.
As early as 1769, Diderot was a supporter of the American Revolution. He corresponded with Benjamin Franklin -- it's not clear if they ever met -- but he was never able to travel to the “land of tolerance, morals, laws, virtue, and liberty.” Diderot's advice to the newly established Republic included the warning "beware of an unbalanced distribution of wealth that will produce a small number of opulent citizens and a horde of citizens in poverty.” (pg. 369)
After Diderot's death, he was “lambasted as an enemy of the people” during the early years of the French Revolution, because the movement would be “contaminated by the atheism that Diderot represented.” Later, Diderot was blamed for the 17,000 executions that constituted The Terror. (pgs. 395-397) This is a game that nobody can win.
“The first step toward philosophy,” Diderot said, “is incredulity.” (pg. 391)