This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book outlines the contributions of Miss Anna Freud, demonstrating how she was able to incorporate new knowledge into the body of psychoanalytic theory through her multi-causal and anti-reductionist "assessments of development" in the normal and pathological child. It addresses key aspects of the alternative centres in a considered treatment of the clinical foundations and explanatory concepts of the theories of both Klein and Fairbairn from the standpoint of the Freudian centre. The book shows that how sensitivity to the countertransference is illuminate both the therapist's self-understanding and his interactions with patients. It illustrates how psychoanalytic theory is used to understand psychosomatic disorders, with particular reference to the case of burning mouth syndrome. The book demonstrates the importance of Freud's central focus on the Oedipus complex for an understanding of his theories of the infantile origins of religious experience.