[2] Mommsen's 1979 book, Arbeiterbewegung und nationale Frage (The Labour Movement and the National Question), a collection of his essays written in the 1960s–70s was the conclusion of his studies in German working class history.

[2] He was a functionalist in regard to the origins of the Holocaust, seeing the Final Solution as a result of the "cumulative radicalization" of the German state as opposed to a long-term plan on the part of Adolf Hitler.

[4] Together with his friend Martin Broszat, Mommsen developed the structuralist interpretation of the Third Reich, that saw the Nazi state as a chaotic collection of rival bureaucracies engaged in endless power struggles.

[7] Mommsen argued that the growth in pacifist feeling in the Federal Republic as reflected in widespread public opposition to the American raid on Libya in April 1986 made it imperative for the Americans and the West German government to promote a more nationalistic version of German history, and that was what was behind the Historikerstreit.

[9] In two articles published in 1966, Mommsen proved as false the claim often advanced in the 1950s that the ideas behind "men of July 20" were the inspiration for the 1949 Basic Law of the Federal Republic.

[11] A major figure in Germany, Mommsen often took stands on the great issues of the day, believing that the responsibility for ensuring the mistakes of the past are never repeated rests upon an engaged and historically-conscious citizenry.