Composed in four parts between 1883 and 1885, much of the work deals with ideas such as the "eternal recurrence of the same", the parable on the "death of God", and the "prophecy" of the Overman. Described by Nietzsche himself as "the deepest ever written", the book is a dense and esoteric treatise on philosophy and morality, featuring as protagonist a fictionalized Zarathustra. A central irony of the text is that Nietzsche mimics the style of the Bible in order to present ideas which fundamentally oppose Christian and Jewish morality and tradition.