The book chronicles the fictitious travels and speeches of Zarathustra. Zarathustra's namesake was the founder of Zoroastrianism, usually known in English as Zoroaster . Nietzsche is clearly portraying a "new" or "different" Zarathustra, one who turns traditional morality on its head. He goes on to characterize "what the name of Zarathustra means in my mouth, the mouth of the first immoralist:"
Thus Spake Zarathustra, Nietzsche's most popular work, is fundamentally different from his other publications and has been called a parable and a poetic fable. In form it imitates parts of the New Testament and the Platonic dialogues. The style is lighthearted, while the message is ironic, frequently ambiguous, and Dionysian. The book is full of metaphors and humorous allusions to specific philosophers and writers. Nietzsche later wrote that it summarized all the important ideas in his writings.