From The Gay Science:
The path to one's own heaven always leads through the voluptuousness of one's own hell.
From Ecce Homo "Thus Spake Zarathustra":
If one had the slightest residue of superstition left in one's system, one could hardly reject altogether the idea that one is merely incarnation, merely mouthpiece, merely a medium of overpowering forces. The concept of revelation that merely describes the facts: in the sense that suddenly, with indescribable certainty and subtlety, something becomes visible, audible, something that shakes one to the last depths and throws one down. One hears, one does not seek; one accepts, one does not ask who gives; like lightning, a thought flashes up, with necessity, without hesitation regarding its form—I never had any choice.
Books on/by Nietzsche at Powell's Books
