Arthur Koestler (1905-1983) was an extraordinary polymath, writer, and political polemicist. His most famous works include the novels Darkness at Noon and Arrival and Departure; his autobiographical writings, including Spanish Testament and Scum of the Earth; and his visionary nonfiction, including The Ghost in the Machine, The Case of the Midwife Toad, and The Sleepwalkers. Herbert Butterfield was an influencial historiographer born in 1900 in Yorkshire, England. A graduate of Peterhouse, University of Cambridge, he is best known for his 1931 work The Whig Interpretation of History. He died in 1979.