Jung’s proposition for the psyche, in this case for a thinking type, though any of the four functions can be the lead function. The light half represents the conscious side of the self, the ego, while the dark area represents the unconscious side of the self, the shadow. The two auxiliary functions are in relative balance in relation to the dominant and repressed functions which have a strong pull on the psyche.
The triangles to each side represent the capacity for conscious development within the psyche; as one of the auxiliary functions become conscious, the other must become unconscious, although both are still only relatively conscious or unconscious.
Jung wrote extensively on the balance and the war between the ego and the shadow, how development and integration of the shadow would hopefully lead to the true self emerging. I think also there were some dangers in the journey to discovering the self. His self-journey into the darkest depths of his unconscious seen in Red Book can give us glimpses of his discoveries and thoughts. “Every step closer to my soul excites the scornful laughter of my devils, those cowardly ear-whisperers and poison-mixers.”
“I, too, lived—which I had not done before, and which I could still do. I lived into the depths, and the depths began to speak. The depths taught me the other truth.” “As long as you are not conscious of yourself you can live; but if you become conscious of yourself you fall from one grave into another. All your rebirths could ultimately make you sick.” “Be silent and listen: have you recognized your madness, and do you admit it? Have you noticed that all your foundations are completely mired in madness? Do you not want to recognize your madness and welcome it in a friendly manner?” ― C.G. Jung, The Red Book: Liber Novus
The ego, in a desperate attempt to escape itself and bring the unconscious to the surface may develop a Thanatos instinct, a pull towards ego destruction and the chaotic tearing down of the perceived self with a reckless abandon of all that has been or is in the pursuit of a transformation into what is perceived as the “true self.” The further the distance between the conscious and shadow, the more this instinct will whisper beautiful visions and tantalizing promises. “You open the gates of the soul to let the dark flood of chaos flow into your order and meaning.”