The weak sides of the pre-Marxian materialism, which appeared as a trend among French materialists (especially in Cabanis and La Mettrie) and later in Feuerbach, and acquired independent form in the middle of the nineteenth century as so-called vulgar materialism (Büchner, Vogt, Moleschott, and others), were linked with an unhistorical, anthropological, naturalistic conception of the nature of man and led to a rapprochement and ultimately to direct identification of the ideal with the material, neurophysiological structures of the brain and their functions. The old materialism set out from a conception of man as part of nature but, not bringing materialism as far as history, it could not understand man in all his peculiarities as a product of labour transforming both the external world and man himself. By virtue of that the ideal could not be understood as the result and active function of labour, of the sensuously objective activity of social man, as the image of the external world arising in the thinking body not in the form of the result of passive contemplation but as the product and form of active transformation of nature by the labour of generations succeeding one another in the course of historical development. The main transformation that Marx and Engels effected in the materialist conception of the nature of the ideal therefore related primarily to the active aspect of the relation of thinking man to nature, i.e. the aspect that had been mainly developed, as Lenin put it, by ‘clever’ idealism, by the line of Plato-Fichte-Hegel, and was emphasised by them in an abstract, one-sided, idealist way.
(Evald Ilyenkov, “The Ideal in Human Activity,” Progress Publishers)
I should be reading Hegel but I just can’t put down the Soviet philosophy and psychology books.
Interesting, because already this excerpt says too little if you’re unfamiliar with some of the subjects, hence it being in a book.