these diagrams represent progressive stages of ego-Self separation appearing in the course of psychological development. The shaded ego areas designate the residual ego-Self identity. The line connecting ego-center with Self-center represents the ego-Self axis—the vital connecting link between ego and Self that ensures the integrity of the ego.
Edinger’s foundational argument that the ego-Self axis — the dynamic relationship of progressive separation and maintained connection — constitutes the structural spine of all psychological development.
, Ego and Archetype: Individuation and the Religious Function of the Psyche, 1972thesis