The self is by definition the totality of all psychical facts and contents.

It consists on one side of our ego consciousness that is included in the unconscious like a smaller circle in a greater one.

So the self is not only an unconscious fact, but also a conscious fact: the ego is the visibility of the self.

Of course, in the ego the self only becomes dimly visible, but you get under favorable conditions a fair idea of it through the ego-not a very true picture, yet it is an attempt.

You see, it is as if the self were trying to manifest in space and time, but since it consists of so many elements that have neither space nor time qualities, it cannot bring them altogether into space and time.

And those efforts of the self to manifest in the empirical world result in man: he is the result of the attempt. So much of the self remains outside, it doesn’t enter this three-dimensional empirical world.
The self consists, then, of the most recent acquisitions of the ego consciousness and on the other side, of the archaic material.

The self is a fact of nature and always appears as such in immediate experiences, in dreams and visions, and so on; it is the spirit in the stone, the great secret which has to be worked out, to be extracted from nature, because it is buried in nature herself.

It is also most dangerous, just as dangerous as an archetypal invasion because it contains all the archetypes: one could say an archetypal experience was the experience of the self.

It is like a personification of nature and of anything that can be experienced in nature, including what we call God. Carl Jung, Zarathustra Seminar, Page 977.