Inasmuch as the I is only the center of my field of consciousness, it is not identical with the totality of my psyche, being merely a complex among other complexes.
Hence I discriminate between the I and the self, since the I is only the subject of my consciousness, while the self is the subject of my totality: hence it also includes the unconscious psyche. In this sense the self would be an (non-material) extension which embraces and includes the I.
In unconscious fantasy the self often appears as the super-ordinated or ideal personality, as Faust is in relation to Goethe and Zarathustra to Nietzsche. ~The Black Books, Vol. I, Page 74