A genetic and functional differentiation between the ego ideal and the ideal ego is proposed. This differentiation allows for a more precise characterization and interpretation of ego libido in symptoms and transference. These genetic and functional differentiations of ego ideal and ideal ego can be used to clarify the differing severities of the types of narcissistic disorder: psychosis, borderline personality disorder, narcissistic personality disorder, from normal maturity. It can also be put to work in refining one's formulation of the narcissistic complications of the classical transference neurosis. This usefulness has been demonstrated in relation to clinical material. In neurosis the ideal ego is a source of symptoms and inappropriate transference demands; in culture it finds embodiment in aggrandized concepts of human nature; in mature adults it is the comforting memory of a vanished splendour.