Ehrenreich's book carefully and clearly enumerates scientific racism's fallacies of logic. ... [His book shows that] although racist eugenics was less logically coherent than hereditary health eugenics, greater numbers of `racially acceptable' Germans appear to have been willing to accept racist eugenic doctrine in order to come to terms with their own failure to act in the face of their neighbors' suffering. In other words, Ehrenreich concludes that .... racial antisemitism was an indicator of what people sincerely hoped to be true. I find this thesis both terrifying and plausible. ... an extremely well-argued, insightful exposition of the institutionalization of racism in everyday life during the Third Reich. -- Peter Fritzsche, H-German author of Germans into Nazis (2008)

How 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 by practitioners of genealogy and eugenics. After the enactment of Nazi racial laws in the 1930s, the Reich Genealogical Authority, employing professional genealogists, became the providers and arbiters of the ancestral proof.

This is the first detailed study of the operation of the ancestral proof in the Third Reich and the link between Nazi racism and earlier German genealogical practices. The widespread acceptance of this racist ideology by ordinary Germans helped create the conditions for the Final Solution.