The Nazi Ancestral Proof: Genealogy, Racial Science, and the Final SolutionHow could Germans, inhabitants of the most scientifically advanced nation in the world in the early 20th century, have espoused the inherently unscientific racist doctrines put forward by the Nazi leadership? Eric Ehrenreich traces the widespread acceptance of Nazi policies requiring German individuals to prove their Aryan ancestry to the popularity of ideas about eugenics and racial science that were advanced in the late Imperial and Weimar periods