After a brief review of the treatment of incest in the Bible, in mythology, and in anthropology, the author underlines the significance of the incest taboo for the symbolic organization of the family, in contradistinction to actual instances of incest and the destructive effect they have on oedipal triangulation and its structural implications. With reference to the father-seducer, the author delineates the psychology of incest. Incestuous fathers are characterized by a specific megalomanic form of narcissism which violates the limits of the object and displays a self-destructive quality vitiating the entire structural cohesion of the family.