"Marx has disclosed the nature of the social process of production, and its fundamental significance as a lever of social development. But he has not fully explained, by what means the nature of the human mind is involved in this material process. Owing to the great traditional influence exerted by bourgeois thought, this weak spot in Marxism is one of the main reasons for the incomplete and erroneous understanding of Marxian theories. This shortcoming of Marxism is cured by Dietzgen, who made the nature of the mind the special object of his investigations. For this reason, a thorough study of Dietzgen's philosophical writings is an important and indispensable auxiliary for the understanding of the fundamental works of Marx and Engels. Dietzgen's work demonstrates that the proletariat has a mighty weapon not only in proletarian economics, but also in proletarian philosophy. Let us learn to wield these weapons!" —Anton Pannekoek

Joseph Dietzgen was a philosopher of social theory and comrade of Karl Marx whose work influenced Vladimir Lenin. He lived in Germany, Russia, and the U.S., where he became the editor of the anarchist publication Chicagoer Arbeiterzeitung after the previous editors were executed for their role in the Haymarket bombings.