Thus Spoke A Book for All and None is a book written during the 1880s by German philosopher Friedrich Nietzsche. Hard to categorize, the work is a treatise on philosophy, a highly praised work of literature, and 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 main person Zarathustra, the work's content extends across a vast range of styles and subject matter. Nietzsche himself described the work as "the deepest ever written".