"This work was Marx's first attempt, with the aid of his materialist conception, to explain a section of contemporary history from the given economic situation. Here the question was to demonstrate the inner causal connection in the course of a development which extended over some years, a development as critical, for the whole of Europe, as it was typical; that is, in accordance with the conception of the author, to trace political events back to the effects of what are, in the last resort, economic causes." (introduction by Engels)