This book develops a novel interpretation of the late nineteenth-century German philosopher Friedrich Nietzsche as holding a distinct and original metaethical position (a theory about our practice of ethics). It is, what might be called, a human-centered metaethics. A central achievement of A Nietzschean Metaethics is to bring Nietzsche into a conversation with the analytic metaethical tradition. To do so, David Emmanuel Rowe interprets Nietzsche’s use of such concepts as the notorious “will to power”; his ideal agent, the superman or Übermensch; nihilism; the eternal recurrence; Perspectivism; and Being and Becoming. The result is a view of Nietzsche as a radical moral error theorist, which is to say he defends the view that all statements that appeal to some value for their truth are false. This theory is radical because Nietzsche argues that insofar as language requires certain concepts for its truth it is in error, in virtue of an appeal to some value. Rowe also offers a view where the increase in one’s power is a standard by which one can make sense of Nietzsche’s so-called re-evaluation of all values. By means of this resolution, Nietzsche criticizes some contemporary themes in metaethics, such as particular views about moral motivation, reasons, moral error theory, and agency.