In the Ricardian period of Political Economy there arises the opposition to it, namely, Communism (Owen) and Socialism (Fourier and Saint-Simon). The latter are still in their swaddling clothes. According to our plan of work we have to deal only with the opposition which springs from the propositions of the economists .... In the same measure as Political Economy grew into a science -- and this growth, as far as its principles are concerned, finds its clearest expression in Ricardo -- it came to regard Labour as the only element of value and the only creator of use-value, and the growth of the productive forces of labour as the only means of a real increase of wealth; the greatest possible development of the productive forces of labour as the economic basis of society. This is indeed the basis of capitalist production. Ricardo s book, by demonstrating the force of the law of value in relation to rent, capitalist accumulation, & c., is really devoted to the removal of all contradictions, or to an elucidation of all phenomena which appear as contradiction to the law of value. But in the same measure as labour comes to be regarded as the only source of exchange value and the active agent of use value, the economists, and particularly Ricardo (and more so Torrens, Malthus, Bailey, & c.), make capital the regulator of production, while labour is in their eyes merely wage-labour, the agent and instrument of which is necessarily a pauper; and this conception is reinforced by the population theory of Malthus. The labourer is but one of the items in the cost of production, whose existence depends on a minimum wage, and who may even sink below the minimum as soon as, from the point of view of capital, he appears as a redundant mass. In this contradiction, Political Economy merely expresses the essence of capitalist production or, if you like, of wage-labour of labour which disowns its own creation, which looks upon the wealth it produces as the wealth of others, which regards its own productive capacity as that of the product (capital), and its own social power as the power of society. And this specific, historical, transient form of social labour the economists regard as the general and only form, as something inevitable; and those conditions of production they pronounce to be the absolutely (not historically) necessary -- the natural and reasonable conditions of the productive work of society. Hopelessly closed in by the horizon of capitalist production, the economists declare the antagonistic form in which the productive work of society appears to-day to be as necessary as social productive service itself when freed from all antagonism. By declaring, on the one hand, labour to be absolute, because they identify wage-labour with social labour, and on the other hand, capital to be absolute, that is, by pronouncing in the same breath the poverty of labour and the wealth of non-labour as the only source of wealth, they are permanently entangled in absolute contradictions, without having the slightest idea of it. Sismondi, by getting an inkling of it, is epoch-making in the history of political economy. However, it was inevitable that the same real evolution, to which the economists gave theoretical expression, would likewise bring the real antagonistic forces to the surface, particularly through the contrast between the growing wealth of the nation and the growing misery of the workers. And as, furthermore, these contradictions found in Ricardo s work a theoretically striking, though unconscious, expression it was but natural that the intellects who took the side of the proletariat would get hold of the contradiction which theory had prepared for them. You say, the latter argued with the economists, that labour is the only source of exchange value and the only active creator of use value, and yet you say, too, that capital is everything and labour nothing or merely a part of the cost of production. You have contradicted yourselves. Capital is nothing but robbery of labour. Labour is everything. This is indeed the last word of all those writings which defend the interests of labour from the standpoint of Ricardo s theories. But as little as Ricardo understood the meaning of his identification of capital and labour do those proletarian defenders understand the contradiction which they point out; therefore it happens that the most prominent among them, such as Hodgskin, for instance, accept all prerequisites of capitalist production as eternal forms and but desire to eliminate capital, at once the basis and the necessary consequence.
Economic Manuscripts: Post-Ricardian Social Criticism by Karl Marx 1863