This document discusses various defense mechanisms described by Sigmund Freud, including denial, displacement, intellectualization, projection, and others. Denial involves refusing to acknowledge an event has occurred. Displacement involves shifting actions from an undesirable target to a substitute target. Intellectualization avoids uncomfortable emotions by focusing on facts and logic. Projection involves assigning one's own uncomfortable thoughts or feelings to others. Freud believed these defense mechanisms help reduce anxiety arising from conflicts between the id, ego, and superego.