The concept of the death instinct is an integral part of the dialectic development of Freud's thinking. His introduction of the concept of repetition compulsion and his deduction from it of the concept of the death instinct introduced two main additions to psychoanalysis: a teleology which complemented the deterministic aspect of the psychic phenomenon; and a new concept of the unconscious as a system that is part of both the repressed and the not repressed material. A new topographical point of view emerged from those new formulations and the basic concept of instincts underwent a radical change. Life and death instincts became the foundation of the interpretation of defences and transference phenomena as well as the representatives of determinism and teleology in the psychoanalytic process. What remains to be developed in this new topography is a study in the mental representation of the death instincts and its symbolism.