What, if some day or night a demon were to steal after you into your loneliest loneliness and say to you: 'This life as you now live it and have lived it, you will have to live once more and innumerable times more' ... Would you not throw yourself down and gnash your teeth and curse the demon who spoke thus? Or have you once experienced a tremendous moment when you would have answered him: 'You are a god and never have I heard anything more divine.

J. In the following few days Nietzsche sent short writings—known as the Wahnbriefe ("Madness Letters")—to a number of friends (including Cosima Wagner and Jacob Burckhardt). Now with the new style of Zarathustra his work became even more alienating and the market received it only to the degree required by politeness.

Nietzsche's key ideas include the "death of God" the Übermensch the eternal recurrence the Apollonian and Dionysian dichotomy perspectivism and the will to power. His sister Elisabeth Förster-Nietzsche acted as curator and editor of Nietzsche's manuscripts during his illness. [citation needed].