In fact, whenever a human being genuinely turns to the inner world and tries to know himself—not by ruminating about his subjective thoughts and feelings, but by following the expressions of his own objective nature such as dreams and genuine fantasies—then sooner or later the Self emerges. The ego will then find an inner power that contains all the possibilities of renewal.
But there is a great difficulty that I have mentioned only indirectly up till now. This is that every personification of the unconscious—the shadow, the anima, the animus, and the Self—has both a light and a dark aspect. We saw before that the shadow may be base or evil, an instinctive drive that one ought to overcome. It may, however, be an impulse toward growth that one should cultivate and follow. In the same way anima and animus have dual aspects: They can bring life-giving development and creativeness to the personality, or they can cause petrification and physical death. And even the Self, the all-embracing symbol of the unconscious, has an ambivalent effect, as for instance in the Eskimo tale, when the "little woman" offered to save the heroine from the Moon Spirit but actually turned her into a spider.
The dark side of the Self is the most dangerous thing of all, precisely because the Self is the greatest power in the psyche. It can cause people to "spin" megalomanic or other delusory fantasies that catch them up and "possess" them. A person in this state thinks with mounting excitement that he has grasped and solved the great cosmic riddles; he therefore loses all touch with human reality. A reliable symptom of his condition is the loss of one's sense of humor and of human contact.