It is generally accepted that among Freud's many contributions to the understanding of the normal and abnormal aspects of mental functioning, The Interpretation of Dreams stands alone and above all others. In this work published in 1900 Freud laid down the foundations of psychoanalytic theory as it was to develop throughout this century. This work not only unravelled the significance of the process of dreaming and allowed for the scientific understanding of the true meaning and nature of the mysterious world of dreams, but created the basis for a general theory of personality capable of encompassing within a single model both the normal and abnormal aspect of mental functioning. Originally published in 1969 Dr Nagera and his collaborators (all analytically trained) from the Hampstead Child Therapy Clinic and Course (now the Anna Freud Centre) isolated from Freud's work twenty-five basic concepts that they considered not only the cornerstones of Freud's theory of dreams but fundamental pillars for the understanding of psychoanalytic theory generally. They include subjects such as dream sources, dream work, dream censorship, manifest content, latent content, condensation, displacement, symbolism, secondary revision and dream interpretation. They are presented in a condensed and concentrated manner containing all significant statements made by Freud at any point in his life on the subject of dreams, as well as tracing the historical development of his ideas wherever significant. References to the sources are given in all instances for the guidance of the student of psychoanalysis, the psychiatrist, the social worker, the psychologist or the scholarly minded reader.