Boundary Transforms

The Self serves as intermediary at the boundary layer between the domains of the conscious ego and the Unconscious.  This layer is a selectively permeable membrane across which mental content transforms as it passes through.  This interface is where the two domains interact, intercommunicate.  The Self, being a transformer, represents the unconscious mind to the conscious ego.  Inasmuch as the ego can accept influences coming through this membrane it becomes more permeable.  The Self, the unitive progressive force in the psyche, can enable an interaction between ego and Unconscious which is a sort of conversation in which the ego 'listens' to the voice of the Deep and replies, as it were.  In this way both the ego and Self become stronger, more developed, and more integrated.  The Unconscious 'speaks' cryptically, in imagery as well as words, and this can be interpreted both intuitively and intellectually.  But the ego can only know the Unconscious by this mediated means, and can surmise its own effect on the Unconscious only through apparent changes in what comes across, and also by changes in its own self.  Though material coming across can come from different sources, the Self is Meta-archetype of Wholeness that can subtly permeate much of this traffic, and whose teleological purpose can steer the development of the whole psyche.

The above is my own attempt to model Jung's concepts.  How mythic and how realistic it is, I don't know.