This paper offers an interpretation of Thus Spoke Zarathustra as Nietzsche’s attempt to write a ‘holy book’ that sanctifies laughter. I compare two important scenes, that of the jester and ropedancer from the Prologue, and that of the ‘ass festival’ from part IV, to show the progressive incorporation of laughter into Zarathustra’s teaching. Throughout, I show that laughter in Zarathustra is ambivalent, possessing both critical and constructive elements. As such, the laughter that is celebrated by the end of the Fourth (...) Part is not merely ironic and self-parodying, but also constitutes a teaching with positive content. In other words, laughter itself represents the heart of Nietzsche’s new revelation of ‘holiness,’ one that challenges regnant expressions of religion and piety while resisting serious, doctrinal formulation. I defend this interpretation against readings that recruit laughter toward a modest philosophical ideal of self-ironization. While laughter does parody and destabilize Zarathustra’s own teachings, it also animates a teaching of holiness that can be helpfully illuminated by Bakhtin’s theory of the carnivalesque. In closing, I suggest that scholars should respect the ‘religion-like’ ambitions of Nietzsche’s work rather than assimilating them to the more modest projects typical of modern scholarship. (shrink)