Sigmund Freud was well aware that his theories were controversial. “What progress we are making,” he commented in 1933. “In the Middle Ages they would have burned me. Now they are content with burning my books.”
As it happened, four years later the new authorities in Vienna weren’t content with just burning his books and Freud had to flee into exile in London. The Nazis had annexed Austria and as a Jew there was a very real threat to his life.