This book illustrates three types of violence based on Zizek’s theory. The author believes that all characters in Eugene O’Neill’s plays exist in a web of power relations and they unconsciously commit different shapes of violence. She tried to analyze Zizek’s theory with the conflicts among all characters in Long Day’s Journey into Night and Mourning Becomes Electra. Although she focused on the three psychologists who works on the psychoanalytic theory in different viewpoints whose names are Freud, Lacan and Zizek. She found out in Zizek’s violence theory, elements had been used in O’Neill’s plays were significant.