The Origins and Evolution of Anthropological Concepts in Christianity For centuries people thought the "will" and the "ego" were genuine causes, facts about consciousness that explained action and responsibility. This is merely a projection of outdated psychology. Modern insight reveals that what we call "the will" doesn't cause action, motives are mere suruface ripples, and the Ego is a fiction of IT ( the body). Humans mistook these illusions for real quantums of force, and we built our metaphysics based upon them and projected it upon the world, turning the Ego into ideal models of "being." Resulting in a massive inherited error: believing in the spirit and the mind as if they were causes via the conception of a "thing in itself..." a summary of one of the 4 great errors by Nietzsche in Twilight of Idols...
But also...
The Greatest Utility of Polytheism 143 Gay Science goes into this. "Not I, Not I, but as an instrument of my God did I do such a thing..." and "the individual set up for themselves their own ideals as Gods, Ubermensch, Heros, and subordinate undermen..."
And Ecce Homo on Inspiration, Nietzsche talks about how, Zarathustra, another Ego within Nietzsche held within himself... he speaks about how this ego waylaid him on his walks to become an unwitting mouth piece... it took him 30 days to write the first three sections in TSZ, 10 days a piece. The words flowed out of him and he just kept writing... there was no stopping to consider this or that and how to organize the book. He just knew from the get go... below are some snips from his discussion.
Has any one at the end of the nineteenth century any distinct notion of what poets of a stronger age understood by the word inspiration?...
There is an ecstasy so great that the immense strain of it is sometimes relaxed by a flood of tears, during which one's steps now involuntarily rush and anon involuntarily lag....
There is the feeling that one is utterly out of hand, with the very distinct consciousness of an endless number of fine thrills and titillations descending to one's very toes....
Everything happens quite involuntarily, as if in a tempestuous outburst of freedom, of absoluteness, of power and divinity....
Hope that helps.