True self

via APA:

in psychoanalytic theory, the total of an individual’s potentialities that could be developed under ideal social and cultural conditions. The term is used in the context of Erich Fromm’s approach to neurosis as a reaction to cultural pressures and repressed potentialities. It is also used in the client-centered therapy of Carl Rogers and in the object relations theory of British psychoanalyst Donald Winnicott (1896–1971). The realization of the true self is a major goal of therapy. source: APA Dictionary

See also:

• Guntrip's concept of the regressed ego in the study of schizoid personality, as "hidden true self"