31. Diderot, Extract from a Letter to Princess Dashkova, 3 April 177149

It was in their correspondence with friends that the Enlightenment philosophers expressed themselves most freely, without fear of censorship. This letter from Diderot to a Russian acquaintance, a confidante of Catherine the Great, is particularly open.50

There is a characteristic spirit for every age. Our own seems to be characterised by the spirit of liberty. The first attack against superstition was violent, excessive. As soon as men dare any sort of assault on the bastion of religion, the most formidable as well as the most respected bastion in existence, there can be no turning back. Once they have looked threateningly upon the majesty of Heaven, they cannot fail, the next instant, to turn their gaze upon those who hold sovereignty on Earth. The cord that binds and humanity and keeps it down is made from two strands; one cannot break without the other also giving way.