Modernism arose in the late 19th and early 20th centuries, due to some major changes in the world, including the rise of industrial societies, the development of larger, more populated cities, and the terrible tragedy of World War I. Because of a combination of these and other factors, people in Western society began to think and believe differently, and this shift in perspective has been labeled “modernism” by historians and philosophers. Religious skepticism and atheism are hallmarks of modernism. Sigmund Freud, who spoke of the drives of the unconscious mind; and Friedrich Nietzsche, who believed that the human “will to power” was important in man’s evolution, were influential in the rise of modernism, and their ideas still help shape culture today.