From 1844–1845 onwards, when Marx's views took shape, he was a materialist, in particular an adherent of L. Feuerbach, discerning subsequently only his weak sides to lie in the insufficient consistency and comprehensiveness of his materialism. The world-historical, "epoch-making" significance of Feuerbach, Marx saw precisely in the decisive break with Hegelian idealism and in the proclamation of materialism, which already "in the eighteenth century, especially in France, was a struggle not only against existing political institutions, but at the same time against religion and theology, but also… against all metaphysics" (in the sense of "drunken speculation" as distinct from "sober philosophy") (The Holy Family in Literary Heritage){52}. "For Hegel," Marx wrote, "the process of thinking, which he transforms even under the name of the Idea into an independent subject, is the demiurge (creator, creator) of the actual… With me, on the contrary, the ideal is nothing other than the material, transplanted into the human head and transformed within it" (Capital, I, Postface to the 2nd Edition{53}). In complete accord with this materialist philosophy of Marx and expounding it, Fr. Engels wrote in Anti-Dühring (see): — Marx became acquainted with this work in manuscript — "… The unity of the world consists not in its being, but in its materiality, which is proved… by the long and difficult development of philosophy and natural science… Motion is the form of being of matter. Nowhere and never has there been or can there be matter without motion, motion without matter… If we pose the question… what is thinking and cognition, whence do they arise, then we shall see that they are products of the human brain and that man himself is a product of nature, developed in a certain natural environment and together with it. It goes without saying by virtue of this that the products of the human brain, which are ultimately also products of nature, do not contradict the rest of nature's connection, but correspond to it". "Hegel was an idealist, i.e. for him the thoughts of our head were not reflections (Abbilder, images, sometimes Engels speaks of 'impressions'), more or less abstract, of actual things and processes, but, on the contrary, things and their development were for Hegel reflections of some Idea that existed somewhere before the emergence of the world"{54}. In his work Ludwig Feuerbach, in which Fr. Engels expounds his and Marx's views on Feuerbach's philosophy and which Engels sent to press after first re-reading the old manuscript of his own and Marx's from 1844–1845 on the question of Hegel, Feuerbach, and the materialist conception of history, Engels writes: "The great fundamental question of all philosophy, and especially of modern philosophy, is the question of the relation of thinking to being, of spirit to nature… what precedes what: spirit nature or nature spirit… Philosophers have divided into two great camps according to how they answered this question. Those who asserted that spirit existed before nature, and who consequently, in one way or another, recognised the creation of the world… formed the idealist camp. Those, however, who took nature as the fundamental principle, aligned themselves with the various schools of materialism". Any other use of the concepts of (philosophical) idealism and materialism leads only to confusion. Marx decisively rejected not only idealism, always connected in one way or another with religion, but also the viewpoint of Hume and Kant, widespread especially in our day — agnosticism, criticism, positivism in various forms — considering such philosophy "reactionary" concession to idealism and at best a "shamefaced smuggling in of materialism through the back door, expelled before the public eye"{55}. See on this question, besides the named works of Engels and Marx, the letter of the latter to Engels of December 12, 1866, where Marx, noting the "more materialist than usual" stance of the well-known naturalist T. Huxley and his acknowledgement that, insofar as "we really do observe and think, we can never step off the ground of materialism," reproaches him for the "loophole" toward agnosticism, Humism{56}. Particularly noteworthy is Marx's view on the relation of freedom to necessity: "Necessity is blind, insofar as it is not conscious. Freedom is the consciousness of necessity" (Engels in Anti-Dühring) = recognition of the objective lawfulness of nature and the dialectical transformation of necessity into freedom (along with the transformation of the unknown but knowable "thing-in-itself" into the "thing-for-us," "the essence of things" into "phenomena"). The principal defect of the "old," including Feuerbachian (and all the more so "vulgar," Büchner-Vogt-Moleschott) materialism Marx and Engels considered to be: (1) that this materialism was "predominantly mechanical," not accounting for the latest development of chemistry and biology (and in our day one should further add: the electrical theory of matter); (2) that old materialism was unhistorical, undialectical (metaphysical in the sense of anti-dialectical), did not consistently and comprehensively carry through the standpoint of development; (3) that they understood the "essence of man" abstractly, rather than as the "aggregate" (concretely determined historically) "of all social relations," and therefore only "explained" the world, whereas the matter concerns the "transformation" of it, i.e. did not understand the significance of "revolutionary practical activity".