Amazing. That is straight out of Mein Kampf. The road from 1855 to 1940 is short indeed. As you can see, the Nazi project had roots going back quite some ways in German history. The destruction of the Jews and subjugation of Poles and other Slavs had been seen as the historical mission of the German people for nearly a century before Hitler embarked on his rampages. So you see that historical actors seldom act alone but instead they are merely the latest players in long-running cultural productions which often started long before their time.
In that sense, Nazism was not alien to German culture at all; instead it was integral to it, and Hitler was simply fulfilling the destiny of the German people.
From Wikipedia:
Gustav Freytag’s literary fame was made universal by the publication in 1855 of his novel, Soll und Haben (Debit and Credit), which was translated into almost all European languages. It was translated into English by Georgiana Harcourt in 1857.
It was hailed as one of the best German novels and praised for its sturdy but unexaggerated realism. Its main purpose is the championing of the German middle class as the soundest element in the nation, but it also has a more directly patriotic intent in the contrast it draws between the supposedly homely virtues of the Germans, while presenting Poles and Jews in a negative light.
In the novel a Jewish merchant is presented as a villain and a threat to Germany. German colonists are presented as “superior” to “wild”, “inferior” and “uncivilized” Poles who are also sometimes depicted sometimes in racist terms.
The novel affirmed the claim of German “masters” to seize the land of the “weaker race” and justified this seizure by supposedly “superior” German culture. The novel applied blatant racism to Slavs while focusing on Poles; the author stated that Poles have “no culture” and are unable to create civilization. Freytag also claimed that Poles will only become proper human beings through German rule and colonization and giving up their language and culture.
Soll und Haben set an example for a body of colonial literature about “eastern marches” and also started a public reinterpretation of the Ostsiedlung, which was now presented as the historical mission of the Germans (Kulturtrager), legitimizing continued the occupation of Polish areas and suppression of the Polish population.