Carl Jung: It is an unconscious prefiguration of the ego.
The term “self” seemed to me a suitable one for this unconscious substrate, whose actual exponent in consciousness is the ego.
The ego stands to the self as the moved to the mover, or as object to subject, because the determining factors which radiate out from the self surround the ego on all sides and are therefore supraordinate to it.
The self, like the unconscious, is an a priori existent out of which the ego evolves.
It is, so to speak, an unconscious prefiguration of the ego.
It is not I who create myself, rather I happen to myself.
This realization is of fundamental importance for the psychology of religious phenomena, which is why Ignatius Loyola started off his Spiritual Exercises with “Homo creatus est” as their “fundamentum.”
But, fundamental as it is, it can be only half the psychological truth.
If it were the whole truth it would be tantamount to determinism, for if man were merely a creature that came into being as a result of something already existing unconsciously, he would have no freedom and there would be no point in consciousness.
Psychology must reckon with the fact that despite the causal nexus man does enjoy a feeling of freedom, which is identical with autonomy of consciousness.
However much the ego can be proved to be dependent and preconditioned, it cannot be convinced that it has no freedom.
An absolutely preformed consciousness and a totally dependent ego would be a pointless farce, since everything would proceed just as well or even better unconsciously.
The existence of ego consciousness has meaning only if it is free and autonomous.
By stating these facts we have, it is true, established an antinomy, but we have at the same time given a picture of things as they are.
There are temporal, local, and individual differences in the degree of dependence and freedom.
In reality both are always present: the supremacy of the self and the hybris of consciousness. ~Carl Jung, CW 11, Para 391