 In the early 20th-century literary modernism developed in the English-speaking world due to a general sense of disillusionment with the Victorian era attitudes of certainty, conservatism, and belief in the idea of objective truth.The movement was influenced by the ideas of Charles Darwin (1809–82) ("On Origin of Species") (1859), Ernst Mach (1838–1916), Henri Bergson (1859–1941), Friedrich Nietzsche (1844–1900), James G. Frazer (1854–1941), Karl Marx (1818–83) ("Das Kapital", 1867), and the psychoanalytic theories of Sigmund Freud (1856–1939), among others.The continental art movements of Impressionism, and later Cubism, were also important inspirations for modernist writers.