Eric Hobsbawn is considered, for very good reasons, one of the greatest historians of the last century. His intellectual figure during the second half of the twentieth century has been a fundamental reference point for a great part of the culture of history - almost the same function that Marc Bloch had, in particular, starting in 1929. From many standpoints, Marc Bloch himself had to combine civil (and political) commitment with the severe rigor of his career as a historian. Hobsbawm, who represented a generation that saw social and political commitment as a life choice, explicitly theorized the coexistence of commitment and scholarship in scientific work. This essay analyzes the paths and results of a highly challenging cultural (and not only cultural) choice.