This document discusses several major intellectual revolutions throughout history: The pre-Socratic revolution questioned the nature of the universe and how it worked. The Copernican revolution introduced the heliocentric model which placed the Sun, not Earth, at the center of the solar system, transforming society's view of the cosmos. Charles Darwin's theory of evolution by natural selection was one of the most controversial as it proposed life descended from common ancestors over time through a process of adaptation, contradicting religious beliefs. Sigmund Freud's psychoanalytic theory introduced the idea of the unconscious mind influencing behavior and composed of three elements - the id, ego and superego. These intellectual revolutions were initially controversial but eventually widely accepted, transforming societies'