Thanks for the link.
I took my quote from a book (that I loaned to friend & did not return) written by a French author. I have never seen it anywhere else.
If I remember correctly, I took the image from an illustration in the book.
The image is an illustration of the Bastille, the storm of which is seen as the culmination of the French Revolution, a massive triumph of evil over good. However, Diderot was speaking of the American Revolution, quite a different historical context.