Thus Spake Zarathustra is a philosophical novel by the German philosopher Friedrich Nietzsche. The work’s hybrid narrative encompasses philosophical sayings, fiction, and poetry, and also serves as a parody of and amendment to the Bible. The plot, a chronicle of fictitious speeches and travels attributed to the ancient sage Zarathustra or Zoroaster, emerges only sporadically throughout the text. Quite different from the historical figure, Nietzsche’s Zarathustra turns morality around and severely criticizes religion, which he views as "the worship of death".
Nietzschean concepts such as the "eternal recurrence of the same events", the "death of God", and the "prophecy" of the Übermensch or "Superman" recur in the text. Nietzsche considered Thus Spake Zarathustra as his masterpiece, and today, it is regarded as the primary precursor to modern existentialist thought.