It is generally accepted that Nietzsche's thought evolved in significant respects over the course of his career.Footnote ¹ As a result, readers of Nietzsche must eventually confront the question: How is Nietzsche's development to be explained, and to what extent do his different writings present us with different Nietzsches?Footnote ² In The Challenge of Nietzsche I tackle that question by reading Nietzsche in light of the autobiographical self-assessments that he produced toward the end of his career. For, through those late autobiographical writings, Nietzsche shows what he found to be most challenging and most unsatisfactory about his own thought, at each major stage of his development. Nietzsche thereby applied to himself a principle that he asserted near the very beginning of his career: “The only criticism of a philosophy that is possible and that also proves something, is to attempt to see if one can live according to it.”Footnote ³

My argument focuses on how Nietzsche used his writings to develop, and then retrospectively assess, two major character types, who also represent two distinct models of how to live: one, the free spirit, that strives to be as independent and critical of the world as possible, and one, Zarathustra, that engages with, cares for, and aims to change the world. According to my argument, Nietzsche developed the ideal of the free spirit in Human, All Too Human to help establish his independence from his former mentor Richard Wagner's project of regenerating Germany's cultural horizons by giving it new, inspiring, quasi-religious myths. But, as Nietzsche worked on Human, All Too Human (especially the final installment of the work, The Wanderer and His Shadow), he realized how psychologically difficult that degree of independence would be for any individual to maintain, because the desire to be part of some larger, world-changing cultural movement would persist. Moreover, when Nietzsche reevaluated Human, All Too Human towards the end of his career, he determined that its shortcomings exemplified an error characteristic of all would-be philosophers: namely, to begin by overestimating one's independence. The limitations of the free spirit ideal, and its defining trait of independence, led Nietzsche to reconsider the project of Wagner, and Wagner's leading theme of love. The loving care for and creative engagement with the world that Nietzsche had encountered in Wagner are revived through the character of Zarathustra—only Nietzsche has Zarathustra aim to accomplish something Wagner had not even attempted, namely, to love the world for what it truly is and then teach the world how to live in light of the truth. But Zarathustra's aim of loving the world for what it is and remaking it on that basis turns out to be no less challenging than the free spirit's aim of living a thoroughly independent life within it.

While it turns out to be extremely difficult to live as either a free spirit or Zarathustra, this does not mean that Nietzsche leaves readers at an impasse. For the autobiographical writings show that he came to see those competing alternatives as reflective of different but deeply ingrained aspects of human nature, which one must learn to negotiate between continually in order to learn ever more deeply about one's self. And I therefore conclude that the most important challenge left for Nietzsche's readers is not to identify one stage of his career or another as the more definitive statement of his thought, but, rather, to judge for themselves whether Nietzsche accurately identified tensions fundamental to human life—and, if so, whether his manner of navigating between those tensions in his own life can help others to do the same in theirs.

That said, the contributors to this symposium all weigh the balance between the different elements of Nietzsche's thought somewhat differently: Paul Franco, Rebecca Bamford, and Rebecca Ploof all highlight constructive, world-changing features of Nietzsche's thought that I put less emphasis on, while Graham Parkes argues that Nietzsche affirmed the world in a more thoroughgoing way than I recognize.