Nietzsche regarded Thus Spoke Zarathustra as his most important philosophical contribution because it proposes solutions to the problems and questions he poses in his later books - for example, his cure for the human disposition to vengefulness and his creation of new values as the antidote to nihilism. It is also the only place where he elaborates his concepts of the superhuman and the eternal recurrence of the same. In this Critical Guide, an international group of distinguished scholars analyze the philosophical ideas in Thus Spoke Zarathustra, discussing a range of topics that include literary parody as philosophical critique, philosophy as a way of life, the meaning of human life, philosophical naturalism, fatalism, radical flux, human passions and virtues, great politics, transhumanism, and ecological conscience. The volume will be invaluable for philosophers, scholars and students interested in Nietzsche's thought.