Introduction -- Psychopathology and difference from the nineteenth century to the present -- The long, slow burn from pathological accounts of race to racial attitudes as pathological -- Hatred and the crowd: World War I and the rise of a psychology of racism -- The Holocaust and post-war theories of antisemitism and racism -- Race and madness in mid-twentieth-century America and beyond -- The modern pathologization of racism -- Conclusion: the specter of science in twenty-first-century racial discourse.