> This is one of those 19th-century clichés that occasionally disfigure Marx's writings.
Whatever it is and whatever it does, it's not found "occasionally."
Its distinction of "human" from animal and inanimate activity is what distinguishes Marx's "materialism" from the "the crude, material fetishism ... where not only the difference between man and animal disappears but even the difference between a living organism and an inanimate object."
"accumulation is nothing but the amassing of the productive powers of social labour, so that the accumulation of the skill and knowledge (scientific power) of the workers themselves is the chief form of accumulation, and infinitely more important than the accumulation—which goes hand in hand with it and merely represents it—of the existing objective conditions of this accumulated activity. These objective conditions are only nominally accumulated and must be constantly produced anew and consumed anew.
'… productive capital and skilled labour are […] one.' 'Capital and a labouring population are precisely synonymous' ( [Hodgskin, Labour Defended against the Claims of Capital, London, 1825,] p. 33).
"These are simply further elaborations of Galiani’s thesis:
'… The real wealth … is man' (Della Moneta, Custodi. Parte Moderna, t. III, p. 229).
"The whole objective world, the 'world of commodities', vanishes here as a mere aspect, as the merely passing activity, constantly performed anew, of socially producing men. Compare this 'idealism' with the crude, material fetishism into which the Ricardian theory develops in the writings 'of this incredible cobbler', McCulloch, where not only the difference between man and animal disappears but even the difference between a living organism and an inanimate object. And then let them say that as against the lofty idealism of bourgeois political economy, the proletarian opposition has been preaching a crude materialism directed exclusively towards the satisfaction of coarse appetites." http://www.marxists.org/archive/marx/works/1863/theories-surplus-value/ch21.htm
Ted