In this classic work, originally published in 1932, Hook set out to demonstrate to the radical and conservative philosophers and activists of the 1920s and 1930s that Marx was a systematic thinker who developed a sound set of philosophical principles. His major argument is that Marx was undogmatic in his approach to philosophy and a critical thinker who assimilated and synthesized a variety of ideas. Hook explains how Marx engaged both Hegel and the young Hegelians in order to develop the notion of the dialectic with Marx's take on historical materialism. The individual chapters engage the reader through the debates and discussions between Marx and young Hegelians such as Moses Hess, who influenced Marx in the study of social and economic problems; Feuerbach, who influenced Marx's view of religion; Bruno Bauer (antiliberalism); Arnold Ruge (philosophy as politics); and Max Stirner (ideals as illusions).