Modernism was a radical shift in art, literature and philosophy in the early 20th century influenced by scientific developments and global events. It questioned what could be truly known about reality and human perception. Major developments in physics with Einstein's theory of relativity and discoveries at the subatomic level challenged traditional views of space, time and matter. The horrors of World War I and developments in psychology with Freud furthered the modernist theme that humans are irrational and reality is ambiguous. Modernist works explored these themes through techniques like stream of consciousness, abstract forms, and nonlinear perspectives that contradicted conventional views of normalcy and perception.