This article reveals the study of psychological violence in the fictional novel of the Belgium author Amélie Nothomb. “Cosmétique de l'ennemi” is the novel presented almosthis article reveals the study of psychological violence in the fictional novel of the Belgium author Amélie Nothomb. “Cosmétique de l'ennemi” is the novel presented almostentirely in the form of a dialogue between the two personalities of a same character. This represents the dual personality disorder between them. This narration describes about the violent acts done by the man who is of the unconscious mind. The verbal conversation between the conscious and unconscious (enemy within) ends up with a violent crime resulting in suicide. The article is based on the theme of violence and it analyses its various forms: physical, psychological (sexual and emotional) as well as the deprivation and neglect. On the whole, this novel explains the three levels of a mind: conscious, subconscious and unconscious. Keywords: Violence, Amélie Nothomb, Sigmund Freud’s theory of id, ego and superego, conscious, subconscious and unconscious, enemy within