On Philosophical Correspondence

“Diderot and Voltaire had first exchanged letters in 1749 when the ‘prince of the philosophes’ had invited the then up-and-coming Diderot to dinner... The two philosophes nonetheless remained in contact (from afar) over the course of the next twenty-eight years. Voltaire sent fifteen more letters. Diderot replied nine times. The relationship, which actually deepened as time went by, was cemented by mutual friends, mutual interests, and a deep reciprocal respect for each other’s intelligence. And yet, well into the 1760s, a continued sense of wariness existed on both sides. In addition to their divergent views on religion—Voltaire remained a Newtonian deist whereas Diderot had long declared himself an unbeliever—the two men evidently had ambivalent feelings about each other’s respective literary careers. Both had invested heavily in the theater, and each also believed that the other was on the wrong path. Voltaire, from Diderot’s point of view, continued to churn out an endless string of rearguard classical dramas and comedies; as for Voltaire, he secretly found Diderot’s bourgeois dramas to be a sad testament to the direction of the theater.”

Andrew Curran, “When Diderot Met Voltaire” - theparisreview.org/blog/2019/01/24/when-diderot-met-voltaire/. Pun intended with recent new materialist critiques of enlightenment era correspondence theory, such as by Quentin Meillassoux.