The Enlightenment and Rousseau

The Encyclopedia celebrated advances in arts and sciences. Rousseau was part of this movement with the other people writing the Encyclopedia. At what point did he turn against that? There was a moment when he was on his way to Vassant in France in 1749 to visit Diderot, who was imprisoned there for violating the censorship. He said that at that moment he was visited by a kind of illumination and an inspiration which led him to say no. All of his critique of civilization flows from that moment.