Sigmund Freud’s book “Psychopathology” is one of his important works in which he sheds light on the relationship between unconscious psychological processes and human behavior. In this book, Freud focuses on explaining pathological psychological phenomena such as forgetfulness, slips of the tongue, obsessions, and dreams, and considers them expressions of internal conflicts repressed in the unconscious mind. The book explains how past experiences, especially in childhood, affect current psychological health and behavior. With his analytical style, Freud provides a new vision for understanding the human psyche by linking pathological symptoms to internal conflicts and unconscious drives.