Arthur Koestler's publications manifest a wide range of political, scientific and literary interests. The Trail of the Dinosaur gathers some of his best-known essays and speeches. The Trail of the Dinosaur , first published in 1955, contains a great deal of Koestler's thinking for the first ten years after the war – a 'farewell to arms' as he wrote in his preface. These essays deal with the political questions that obsessed him for the best part of a quarter of a century. The essays in 'The Trail of the Dinosaur' cover the decade 1946–55-the early or classical period of the Cold War. In that confrontation the West was on the defensive, and the majority of its progressive intellectuals were still turning a benevolently blind eye on Soviet foreign policy and the facts of life behind the Iron Curtain . In the dramatic contest between Whitaker Chambers and Alger Hiss, which has been called the Dreyfus Affair of our century, progressive opinion stood firmly behind Hiss. And when, in the New York Times, I took Chambers' part, I became, if possible, even more unpopular among self-styled progressives than I had been before. In 1937, during the Civil War in Spain, I spent three months under sentence of death as a suspected spy, witnessing the executions of my fellow prisoners and awaiting my own. These three months left me with a vested interest in capital punishment-rather like 'half-hanged Smith', who was cut down after fifteen minutes and lived on.