Why Nietzsche Rejected Purity

In this lecture, Ken Gemes examines Friedrich Nietzsche's deeply ambivalent relationship to nineteenth-century degeneration theory, arguing that a careful reading reveals him as one of its most sophisticated critics rather than its philosophical champion. Gemes begins by acknowledging the flat reading: passages from On the Genealogy of Morals, The Antichrist, and Ecce Homo deploy the full degenerationist vocabulary of poison, parasitism, and elimination, and some National Socialists exploited precisely this surface. But Gemes argues that Nietzsche's real project is anti-Manichean. Through his account of master and slave morality, his complicated admiration for Jewish creativity, and his insistence that Christianity represents a disaffirmation of life, Nietzsche is not targeting so-called degenerates for elimination but subverting his German audience's self-understanding. The lecture's pivot comes with the section "Ennoblement Through Degeneration" from Human, All Too Human, where Nietzsche argues that genuine strength means absorbing infection rather than excluding it. Drawing on Claude Bernard's physiology, Nietzsche reframes health as dynamic balance, not purity, placing him squarely against the eliminationist logic that defined the degenerationist tradition.