The relation between the forces of production and the social relations of production in the thought of Karl Marx is usefully exemplified and epitomized in footnote 34 of the famous chapter on “The Fetishism of Commodities” in Das Kapital. Let us quote it in full here:
I seize this opportunity of shortly answering an objection taken by a German paper in America, to my work, “Zur Kritik der Pol. Oekonomie, 1859.” In the estimation of that paper, my view that each special mode of production and the social relations corresponding to it, in short, that the economic structure of society, is the real basis on which the juridical and political superstructure is raised and to which definite social forms of thought correspond; that the mode of production determines the character of the social, political, and intellectual life generally, all this is very true for our own times, in which material interests preponderate, but not for the middle ages, in which Catholicism, nor for Athens and Rome, where politics, reigned supreme. In the first place it strikes one as an odd thing for any one to suppose that these wellworn phrases about the middle ages and the ancient world are unknown to anyone else. This much, however, is clear, that the middle ages could not live on Catholicism, nor the ancient world on politics. On the contrary, it is the mode in which they gained a livelihood that explains why here politics, and there Catholicism, played the chief part. For the rest, it requires but a slight acquaintance with the history of the Roman republic, for example, to be aware that its secret history is the history of its landed property. On the other hand, Don Quixote long ago paid the penalty for wrongly imagining that knight errantry was compatible with all economic forms of society.
Note here how unfair Marx’s reply to the “German paper’s” criticism of his thesis is: true enough, the dependence of ideology on the real forces and relations “of production” cannot seriously be questioned. Yet Marx could have been fairer to the underlying significance of the critique implicit in the German paper – which is that there is a major difference between capitalism and previous modes of production in that only in capitalism is the production of surplus value the overriding aim and objective and even ethico-political value of human society! Indeed, even for Marx, this is what distinguishes capitalism from everything else – not that surplus value is produced, but much rather how surplus value is produced, and to what end that surplus value is applied, which is part and parcel of how the surplus value is produced in the first place! Marx overlooks here this implicit contention in the objection moved by the German paper, namely, that the mode of production of surplus value and the mode and ends of its application are relevant political conditions of the forces and relations of production themselves! Instead, Marx completely ignores this aspect of the objection and chooses to focus on the much simpler question of the dependence of ideology (the superstructure) on production (the base). The source of Marx’s misapprehension – one that afflicts his entire oeuvre – is his atavistic attachment to the phrase “gaining a livelihood”, from which he infers that the mode of “gaining a livelihood” is hermetically sealed from and independent of “ideological values”. Yet, even the most desultory reflection on this matter will show that how a society “gains its livelihood” is dictated in large part precisely by those “ideological values and institutions” which he so summarily dismisses! It is this quintessential aspect of the question of the relationship between the Political and the Economic that Max Weber will develop most explicitly first in Die Protestantische Ethik in 1904 and later in Die geistige Arbeit in 1919.
For Marx, the ideological superstructure of human societies is “explained [by] the mode in which they gained a livelihood” – in other words, by their “mode of production”. The mode of production is a combination of “the forces of production”, which refers to the degree of technological advancement of society, and by “the social relations of production”, which refer to the adherence of the superstructure to the forces of production, to the manner in which the superstructure interacts with the forces of production. It is this interaction that forms the economic base on which the superstructure depends. Social relations of production refer to this complex interaction between ideological superstructure and forces of production.
Social relations are closely bound up with productive forces. In acquiring new productive forces men change their mode of production; and in changing their mode of production, in changing the way of earning their living, they change all their social relations. The hand-mill gives you society with the feudal lord; the steam-mill society with the industrial capitalist..(Marx, The Poverty of Philosophy.)
The social relations of production or economic base form a complex interaction between ideological superstructure on one side and forces of production on the other. The ideological superstructure can either facilitate or impede the forces of production – and if the latter, the social relations must change together with the superstructure. When the social relations of production – the interaction of ideological superstructure and economic base – contrast and impede or hinder the forces of production, it is the superstructure that must give way. Only in communism will the ideological superstructure disappear and the social relations of production coincide with the forces of production and enhance them. Thus, it is not so much that the superstructure has nothing to do or does not interact with the forces of production; it is rather that the superstructure can hold back the forces of production only so much. The ideological superstructure – the state, religion, other ideologies – influences the forces of production not essentially but in terms of either promoting them or holding them back. To that degree it forms part of the social relations of production by determining how the surplus social product is employed.
After the triumph of the bourgeoisie, there was no longer any question of the good or the bad side of feudalism. The bourgeoisie took possession of the productive forces it had developed under feudalism. All the old economic forms, the corresponding civil relations, the political state which was the official expression of the old civil society, were smashed.
Thus, feudal production, to be judged properly, must be considered as a mode of production founded on antagonism. It must be shown how wealth was produced within this antagonism, how the productive forces were developed at the same time as class antagonisms, how one of the classes, the bad side, the drawback of society, went on growing until the material conditions for its emancipation had attained full maturity. Is not this as good as saying that the mode of production, the relations in which productive forces are developed, are anything but eternal laws, but that they correspond to a definite development of men and of their productive forces, and that a change in men's productive forces necessarily brings about a change in their relations of production? As the main thing is not to be deprived of the fruits of civilization, of the acquired productive forces, the traditional forms in which they were produced must be smashed. From this moment, the revolutionary class becomes conservative.(The Poverty of Philosophy)
Once again, Marx reasserts the dependence of social relations on productive forces. What is noteworthy in this passage is that Marx’s notion of “productive forces” is at once physiological or naturalistic in one aspect, and political in another, in the sense that it subsumes “class antagonism” into the category of “forces of production” in such a way that clearly Marx sees political antagonism as part and parcel of the physiological or naturalistic “development of the forces of production”. The clear implication is that Marx subsumes the Political to the sphere of “material conditions” as part of a natural physiological evolution of the human species. The Hegelian teleological derivation of this interpretation of history – from the viewpoint of his “historical materialism” – is unmistakeable. And so is the eschatological motif in Marx’s entire oeuvre – the historical material inevitability of communism as the “final stage of society”, one in which class antagonism will vanish from human history. Only in communism the antagonism between social classes is finally superseded and abolished (aufgehoben) - here is the famous Hegelian Aufhebung in Marxian version, the materialist obverse or inverse of Hegelian dialectical materialism – “stood on its feet” – but with “the cunning of Reason” preserved in the guise of “material production” and “productive forces”, or Nature or physis. (Recall that Marx’s doctoral thesis was on the conception of Nature [physis] in Democritus and Epicurus.) For Marx, it is only once the state of society has reached a point where the forces of production are sufficiently contrasted or held back by the social relations of production (the interaction between superstructure and forces of production) – only at that stage society is ripe for revolution and the supersession (Aufhebung) of the preceding mode of production.