Interpretation of Nietzsche's thought is a complex enterprise. Because of his avoidance of any conventional philosophical system and his many experiments with styles and genres, Nietzsche's writings seem to demand a sense of active reading. The “Nietzsche” that emerges from scholarly discussion typically depends on the interests of the interpreter and especially often those of the interpreter's discipline. Themes which are taken to be most central to Nietzsche's philosophy often depend on which works are regarded as most important or most accessible; but the relative importance which attaches to each of Nietzsche's works is by no means obvious. Indeed, Nietzsche scholarship has experienced fads with regard to given points of interest. As we will consider below, Thus Spoke Zaiathustia's celebrity outside of Germany declined after the Nazis invoked it for propagandistic purposes, while Nietzsche's early essay “On Truth and Lies in a Nonmoral Sense” has assumed new importance in recent literary-critical discussion, in part because it suggests that all language is metaphoric.

The importance to the humanities and to our culture of the nineteenth-century German philosopher and writer Friedrich Nietzsche may require little motivation or discussion. He was quite simply one of the most influential modern European thinkers. His attempts to unmask the root motives which underlie traditional Western philosophy, morality, and religion have deeply affected subsequent generations of philosophers, theologians, psychologists, poets, novelists and playwrights. Indeed, one contemporary English-speaking philosopher, Richard Rorty, has characterized the entire present age as “post-Nietzschean.” That is because Nietzsche was able to think through the consequences of the triumph of the Enlightenment's secularism - captured in his observation that “God is dead” - in a way that determined the agenda for many of Europe's most celebrated intellectuals after his death in 1900. An ardent foe of nationalism, anti-Semitism, and power politics, his name was later invoked by Fascists and Nazis to advance the very things he loathed.