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 articulates the foundational structural model of the ego's developmental differentiation from the Self, mediated by the ego-Self axis whose integrity is essential to psychological health.
, Ego and Archetype: Individuation and the Religious Function of the Psyche, 1972thesis