Flaubert was in a sense the forerunner of writing scruples. I do believe that in the eighteenth century, say, Voltaire or Rousseau wrote much more naturally than people did from the nineteenth century onwards. Flaubert sensed this more than any other writer. If you look at Rousseau’s letters, for instance, they’re beautifully written. He dashed off 23 in a day if necessary, and they’re all balanced, they’re all beautiful prose. Flaubert’s letters are already quite haphazard; they’re no longer literary in that sense. He swears, he makes exclamations, sometimes they’re very funny. But he was one of the first to realise that there was appearing in front of him some form of impasse. And I think nowadays it’s getting increasingly difficult because writing is no longer a natural thing for us.
– Sebald (via here)