In the volume before us we have the first two books of what was to be Nietzsche’s greatest theoretical and philosophical prose work. The reception given to Thus Spake Zarathustra had been so unsatisfactory, and misunderstandings relative to its teaching had become so general, that, within a year of the publication of the first part of that famous philosophical poem, Nietzsche was already beginning to see the necessity of bringing his doctrines before the public in a more definite and unmistakable form.