Marx and Engels on Immanuel Kant

Karl Marx and Friedrich Engels dismiss Kant as a bourgeois moralist in their book The German Ideology: "The state of affairs in Germany at the end of the last century is fully reflected in Kant’s Critique of Practical Reason. While the French bourgeoisie, by means of the most colossal revolution that history has ever known, was achieving domination and conquering the Continent of Europe, while the already politically emancipated English bourgeoisie was revolutionizing industry and subjugating India politically, and all the rest of the world commercially, the impotent German burghers did not get any further than “good will”. Kant was satisfied with “good will” alone, even if it remained entirely without result, and he transferred the realization of this good will, the harmony between it and the needs and impulses of individuals, to the world beyond. Kant’s good will fully corresponds to the impotence, depression and wretchedness of the German burghers, whose petty interests were never capable of developing into the common, national interests of a class and who were, therefore, constantly exploited by the bourgeois of all other nations. These petty, local interests had as their counterpart, on the one hand, the truly local and provincial narrow-mindedness of the German burghers and, on the other hand, their cosmopolitan swollen-headedness."

They call Kant a whitewashing spokesman for the German middle class: "The characteristic form which French liberalism, based on real class interests, assumed in Germany we find again in Kant. Neither he, nor the German middle class, whose whitewashing spokesman he was, noticed that these theoretical ideas of the bourgeoisie had as their basis material interests and a will that was conditioned and determined by the material relations of production. Kant, therefore, separated this theoretical expression from the interests which it expressed; he made the materially motivated determinations of the will of the French bourgeois into pure self-determinations of “free will”, of the will in and for itself, of the human will, and so converted it into purely ideological conceptual determinations and moral postulates. Hence the German petty bourgeois recoiled in horror from the practice of this energetic bourgeois liberalism as soon as this practice showed itself, both in the Reign of Terror and In shameless bourgeois profit-making." 

But they are not always negative on Kant. For instance, in the Preface to Socialism, Utopian and Scientific, Engels gives credit to Kant for being the founder of German idealism of which Marxism is an offshoot. "We German socialists are proud that we trace our descent not only from Saint Simon, Fourier and Owen, but also from Kant, Fichte and Hegel.”