Karel Capek was a Czech writer who is best known for his 1920 play R.U.R. (Rossum's Universal Robots). The play was Capek's first international success, introduced the word 'robot' to the English language and was one of the works that pioneered the theme of robots in fiction. The idea of artificial intelligence and what it means to be human became a popular one in future science fiction tales such as Asimov's I, Robot and Philip K. Dick's Do Androids Dream of Electric Sheep? Capek also wrote many other works of fiction and non-fiction, including detective stories, fairytales and travel books. His most important works, such as The Tales from Two Pockets and the trilogy Hordubal, Meteor and An Ordinary Life, deal with epistemology (the study of knowledge). A fervent anti-fascist and anti-communist, Capek campaigned for freedom of expression and was a member of the International PEN Club. He died of double pneumonia on Christmas Day 1938, aged 48.