In most of Jung's early writings, the Self is usually described as the ordering principle which unifies the various archetypal contents and balances the opposites in the psyche during the analytic process, leading toward the "goal" of individuation or "self-realization." Jung reached this hypothesis empirically. In his own dreams and those of analysands, he found himself confronted by a source of apparent wisdom in the unconscious that seemed to present a very different image of the patient's true life than that held by the patient's ego. This "center" in the unconscious seemed to compensate for the ego's one-sided attitudes as if it had the "intention" of correcting the patient's imbalanced attitude and envisioned a "goal" that seemed to embrace the patient's whole personality - not just his ego. Moreover, this "center" of wisdom in the psyche seemed to "present itself" in dreams through numinous imagery that connoted a sacred "otherness," imperishability, resolution of conflict, wholeness, ineffable beauty. For these reasons, Jung decided that, whereas the ego was the center of consciousness, the Self represented the subject of the psyche's totality which includes both conscious and unconscious. > Intellectually the Self is no more than a psychological concept, a construct that serves to express an unknowable essence which we cannot grasp as such, since by definition it transcends our powers of comprehension. It might equally well be called the "God within us." The beginnings of our whole psychic life seem to be inextricably rooted in this point, and all our highest and ultimate purposes seem to be striving towards it." > > (Jung, 1934a: para. 399) Following from these definitions, many of Jung's followers have tended to emphasize the Self's prescient "unfolding" through the individuation process -its nudging the sometimes resistant ego toward its prespecified "plan" of individual wholeness. These authors acknowledge that this "nudging" can be disagreeable, even terrifying, but the implication is that the Self knows best what is good for the ego (see Whitmont, 1969). Sometimes the Self is presented as an oracular voice which speaks in the interior world, forcing the "host" into moral conflict with the collective values if he or she is to realize a unique personal truth (see Neumann, 1969). Others, following up Jung's idea that the Self is a "prefiguration of the ego," emphasize the dialectical relationship between the ego and the Self and the slowly developing "axis" between them, analogous on an individual level to the relationship between the incarnate Christ and his trans-personal Father (see Edinger, 1972). In all these approaches, the Self is imagined as the supreme authority, the longed-for transcendent unity of life, a unity of opposites, the eternal One having entered time.
— Donald Kalsched
Jung reached the Self empirically — that is worth sitting with before the concept acquires the authority it tends to accumulate. Dreams kept confronting him with something that seemed to know more than the ego knew, something that compensated for one-sidedness with a kind of patient, non-negotiable counterweight. He named it provisionally: the center of psychic totality, not quite God, not quite self, something for which "God within us" was the nearest available metaphor. The concept was honest about its own limits — "intellectually no more than a psychological construct," he said, for an unknowable essence that transcends comprehension.
What happened after Jung is the more revealing story. The Self became, in many of his followers' hands, a guarantor — a sovereign intelligence nudging the ego toward its prespecified wholeness, a supreme authority one could orient toward, a transcendent unity that waited patiently at the end of the individuation road. The relief this provides is real, which is precisely why it deserves scrutiny. When the Self is imagined as the eternal One having entered time, as Kalsched puts it, something has shifted from Jung's careful empiricism toward a schema that promises the ego what the ego most wants: that its suffering is purposeful, supervised, moving somewhere. That is a different claim than the one Jung made, and it carries a different weight on the soul — one that Kalsched's own work on trauma will eventually complicate at the root.
Donald Kalsched·The Inner World of Trauma: Archetypal Defences of the Personal Spirit·1996