The Biology of Evil

Ken Gemes traces the evolution of the concept of evil, exposing the philosophical underpinnings of an idea that would have a huge impact in the 19th and 20th centuries. In the Enlightenment, evil was understood as a species of error, a failure of reason that education could correct. But in the nineteenth century, a dramatic shift occurred: evil moved from the mind to the body. A new scientific literature emerged claiming that criminals, the insane, and entire peoples were biologically degenerate, throwbacks to a more primitive stage of human development. This forgotten discourse, the rhetoric of degeneration, is the subject of the course.

The lectures begin with the foundational figures of degeneration theory: Philippe Pinel, who recast insanity as a medical condition; Benedict Morel, who coined the concept of hereditary degeneration; and Charles Darwin, whose theory of evolution inadvertently gave scientific authority to fears of civilizational decline. From there, Gemes introduces Cesare Lombroso, the Italian criminologist who argued that criminals were evolutionary atavisms, and Max Nordau, whose bestselling book Degeneration warned that modern civilization itself was decaying from within.

Gemes then shows how these scientific ideas saturated the culture at large. Bram Stoker's Dracula, Robert Louis Stevenson's Dr. Jekyll and Mr. Hyde, and other famous novels turn out to be vehicles for degenerationist anxiety. The poet Baudelaire embraced the idea that evil is universal and inescapable, while Marx and Wagner absorbed the metaphors of degeneration into their critiques of modernity, often directing them against Jews.

The course finds its heroes in thinkers who rejected the Manichean logic at the heart of degeneration theory. Nietzsche argued that sickness and health are not opposites to be separated but forces to be balanced within every individual. Freud, despite his own complicated debts to degenerationist thinking, insisted on a developmental story of the mind that replaced hereditary doom with the possibility of understanding. Both refused the fantasy that evil could be isolated in a despised group and surgically removed from humanity.

The final lecture confronts the catastrophic endpoint of this rhetoric in Adolf Hitler's Mein Kampf, where the metaphors of poison, infection, and parasitism that had circulated for decades were literalized into a program of extermination. Gemes does not draw a straight line from degenerationist thinkers to the Holocaust, but he argues that degeneration theory created the conceptual space in which such atrocities became thinkable. He closes by noting that these same metaphors of contamination and invasion are resurfacing in our own time, making this lost history urgently relevant once again.