hus Spoke Zarathustra: A Book for All and None is a book written during the 1880s by the German philosopher, Friedrich Nietzsche. Hard to categorise, the work is a treatise on philosophy, a masterly work of literature, in parts a collection of poetry and in others a parody of and amendment to the Bible. Consisting largely of speeches by the book's hero, prophet Zarathustra, the work's content extends across a mass of styles and subject matter. Nietzsche himself described the work as "the deepest ever written".