La decadencia de Occidente
A cyclical theory of history was adopted by Oswald Spengler (1880–1936), a German historian who wrote "The Decline of the West" in 1920. World War I, World War II, and the rise of totalitarianism demonstrated that progress was not automatic and that technological improvement did not necessarily guarantee democracy and moral advancement. British historian Arnold J. Toynbee (1889–1975) felt that Christianity would help modern civilization overcome its challenges.