 They also disagreed about the usefulness of Hegel. Lange suspected that Hegelian dialectic, even in the more empiricist and materialist form that Marx deployed it, was not very useful for purposes of explanation. He expresses his surprise that at a time in which Hegel was no longer taken seriously in philosophy, Hegelian ideas could be so influential in the workers’ movement, in the thought of Lassalle and Marx (Lange 1894a, 247–249, 260–262). Lange had immense respect for Marx, and thought of him as the leading economist of the time. However, he thought that when it came to Marx’s writings, the Hegelian “speculative form … tiresomely intrudes on the content of some parts of the work to the disadvantage of its effectiveness” and undermines the effect of the “astounding” display of detailed empirical evidence (Lange 1894a, 248). Lange also thought that the emphasis on revolution, and the thought that a revolution could somehow suddenly change the conditions of the working class and the mode of production, was also the result of the negative influence of Hegel. Marx and Engels, on the other hand, were committed to some kind of dialectic form of explanation. Marx thought that Lange’s basic attitude towards Hegel and dialectic was fundamentally mistaken—“simply childish”—and, indeed, showed that Lange “understands rien [nothing] about Hegel’s method and therefore, second, still less about my critical manner of applying it” (Marx and Engels 1975, 43: 528). There is evidence that Lange did understand what was at stake, though, as is shown by his clear discussion of idealism in psychology, and in the study of nature in general, in his “Seelenlehre” (Lange 1859–1875, 144–45).