In this brief section, Nietzsche sketches out the process through which humans went from trusting their senses (knowing that the world they could touch, see, hear, etc. was real and meaningful) to distrusting their senses and giving in to nihilism. Nietzsche is suggesting that intellectual culture (in the western world) has deteriorated ever since Socrates taught people to prioritize reason over human instinct. The final line of this passage alludes to Nietzsche’s
Thus Spoke Zarathustra, a work of philosophical fiction about Zarathustra, a hermit and prophet who returns to the world to spread the word that God is dead (that humanity is no longer beholden to the old moral system). When Nietzsche states that Zarathustra begins where people have learned to
doubt the world as it appears to them, he’s saying that contemporary society’s skepticism justifies a complete overhaul of the old values.