Also sprach Zarathustra was conceived and written by Friedrich Nietzsche during the years 1881 -1885; the first three Parts were published in 1883 and 1884. The book formed part of his 'campaign against morality', in which Nietzsche explored the ethical consequences of the 'death of God'. Heavily critical not only of Christian values but also of their modern replacements, Thus spoke Zarathustra argues for a new value-system based around the prophecy of the Ubermensch, or Superman.

For the first time, Nietzsche gives his philosophy a narrative frame: the founder of the ancient religion of Persia, Zarathustra, takes the central role. Rejected by society at large, Zarathustra gains a devoted band of followers to whom he delivers 'discourses' on a huge range of subjects. Haunted by visions and driven by his own 'will to power', Zarathustra eventually leaves these friends to return to his lonely mountain home, where he makes his most important discovery: that of the 'eternal return'.

A literary as well as a philosophical masterpiece, Thus spoke Zarathustra survived an initially poor reception, to be recognised as a seminal text in modern culture. Its appropriation by the National Socialist movement in Germany early in the twentieth century has tainted its reputation unjustly; but there are signs that the rehabilitation of Nietzsche, and of this, his most incendiary work, is almost complete.