On which theoretical basis to build the critique of bourgeois society? This consideration led Marx to go more deeply into problems of method, when he started to write Capital, and to formulate the guiding principles for his research. The upshot was one of the most extensively debated manuscripts in the whole of his oeuvre: the so-called ‘Introduction’ of 1857. This text contains the most extensive and detailed pronouncement that Marx ever made on epistemological questions and is essential to understand his conception of historical materialism beyond his early writings. In this lecture, Professor Musto will start with the analysis of this topical text and will continue to analyse Marx’s historical materialism in light of his latest research made between 1879 and 1882. Usually focused only on the analysis of The German Ideology and of the so-called “young Marx”, this lecture will play more attention to the mature elaboration of Marx and on the theoretical implications for us today.