The Nazis burned books that they considered "un-German" and opposed to their ideology. These included:

• Books by Jewish authors, regardless of the field, as Nazis were obsessively antisemitic.
• Works promoting communism, socialism, and Marxism, including all works by Karl Marx, Friedrich Engels, and Vladimir Lenin.
• Pacifist literature and anti-war books, since Nazis saw pacifism as dangerous and weak.
• Books praising or defending the Weimar Republic and parliamentary democracy.
• Writings condemning or criticizing the Nazi Party and its ideology.
• Literature with liberal, democratic tendencies and attitudes.
• Works by political opponents like socialists, anarchists, and leftist writers.
• Books on sexuality and sexual education that did not align with Nazi racial ideology, including works by sexologists like Magnus Hirschfeld.
• Art and literature considered decadent, modernist, or damaging to German culture and purity.
• Popular entertainment literature seen as superficial or promoting bourgeois values.
• Pornography and explicit literature.
• Books deemed to degrade or threaten German racial purity.

The book burnings were a cultural cleansing aimed at destroying dissenting ideas and promoting Nazi racial and political ideologies. They targeted thousands of authors and works, from socialist theorists to pacifist novelists, Jewish intellectuals, liberal democrats, and avant-garde artists.