His most well-known book, "The Crisis of German Ideology: Intellectual Origins of the Third Reich" (1964), analyses the origins of the nationalist belief system. Mosse claimed, however, that it was not until his book "The Nationalization of the Masses" (1975), which dealt with the sacralization of politics, that he began to put his own stamp upon the analysis of cultural history. He started to write it in the Jerusalem apartment of the historian Jacob Talmon, surrounded by the works of Rousseau. Mosse sought to draw attention to the role played by myth, symbol, and political liturgy in the French Revolution. Rousseau, he noted, went from believing that "the people" could govern themselves in town meetings, to urging that the government of Poland invent public ceremonies and festivals in order to imbue the people with allegiance to the nation. Mosse argued that there was a continuity between his work on the Reformation and his work on more recent history. He claimed that it was not a big step from Christian belief systems to modern civic religions such as nationalism.