I give this book five stars solely for its historical value. Rosenberg was one of the Nuremberg defendants hanged.
There is much content in this book, and I will only touch on a few themes. Rosenberg relates his thinking to topics as diverse as the ancient Greeks, Teutonic mythology, religion (especially Christianity), papal politics, past German statesmen and philosophers, modern science, etc.
Rosenberg faults the Bible for teaching creation out of nothing, a 6,000 year-old earth, and the existence of Noah's Ark (p. 394). Unlike Hitler, who summarily dismissed Christianity as an effeminate Jewish invention, Rosenberg spends much time trying to "de-Judaize" Christianity, going as far as insisting that Jesus Christ was not a Jew. (p. 382)
The Jews-are-parasites theme of MEIN KAMPF is repeated by Rosenberg (p. 286). He also praises Emmanuel Kant for calling Jews "a nation of shopkeepers and swindlers" and Arthur Schopenhauer for calling Jews "the great masters of lies." (p. 434)
As for the Slavs, Rosenberg cites the Czechs as consisting of a Nordic-Slavic nobility and lower orders. (p. 57) This echoes the Nazi belief that all Slavic leadership, achievement, culture, creativity, etc., is produced by a thin upper crust of Slavicized Germans. There is no such thing as Slavic culture; it is all copied German culture. During WWII, Rosenberg's views on "race defilement" (pp. 373-374) were widely put into practice.
Nazism is sometimes conflated with nationalism. Actually, Rosenberg criticized it: "The old nationalism was manifoldly not sincere. It was a mere cover for large agrarian and industrial, and later, finance-capitalist, private interests." (p. 335). Genuine nationalism, according to Rosenberg, existed only when serving the needs of the Volk, and fused with socialism. (pp. 335-336, 338) In fact, Rosenberg commented: "Thus whoever wishes to be a nationalist today, must also be a socialist." (p. 336)
Indeed, there is no doubt about the fact that National Socialism was a form of socialism. In common with other Nazis (e. g., Goebbels), Rosenberg often attacked both capitalism and Communism, sometimes in the same sentence: e. g., "...bourgeois avariciousness, criminal Marxist insanity..." (p. 351) He praised Bismarck for having socialized the railways. (p. 336, 339)
National Socialism can best be understood as a racialist-socialist system that superseded all previous concepts of government, nation, etc. Rosenberg said: "Our new idea places Volk and race higher than the existing state and its forms. It declares protection of the people to be more important than protection of a religious creed, a class, of the monarchy or the republic." (p. 339)