Secondly: To each capitalist, the total mass of all workers, with the exception of his own workers, appear not as workers, but as consumers, possessors of exchange values (wages), money, which they exchange for his commodity. They are so many centres of circulation with whom the act of exchange begins and by whom the exchange value of capital is maintained. They form a proportionally very great part – although not quite so great as is generally imagined, if one focuses on the industrial worker proper – of all consumers. The greater their number – the number of the industrial population – and the mass of money at their disposal, the greater the sphere of exchange for capital. We have seen that it is the tendency of capital to increase the industrial population as much as possible. Actually, the relation of one capitalist to the workers of another capitalist is none of our concern here. It only shows every capitalist’s illusion, but alters nothing in the relation of capital in general to labour. Every capitalist knows this about his worker, that he does not relate to him as producer to consumer, and [he therefore] wishes to restrict his consumption, i.e. his ability to exchange, his wage, as much as possible. Of course he would like the workers of other capitalists to be the greatest consumers possible of his own commodity. But the relation of every capitalist to his own workers is the relation as such of capital and labour, the essential relation. But this is just how the illusion arises – true for the individual capitalist as distinct from all the others – that apart from his workers the whole remaining working class confronts him as consumer and participant in exchange, as money-spender, and not as worker. It is forgotten that, as Malthus says, ‘the very existence of a profit upon any commodity pre-supposes a demand exterior to that of the labourer who has produced it’, [40] and hence the demand of the labourer himself can never be an adequate demand. Since one production sets the other into motion and hence creates consumers for itself in the alien capital’s workers, it seems to each individual capital that the demand of the working class posited by production itself is an ‘adequate demand’. On one side, this demand which production itself posits drives it forward, and must drive it forward beyond the proportion in which it would have to produce with regard to the workers; on the other side, if the demand exterior to the demand of the labourer himself disappears or shrinks up, then the collapse occurs. Capital itself then regards demand by the worker – i.e. the payment of the wages on which this demand rests – not as a gain but as a loss. I.e. the immanent relation between capital and labour asserts itself. Here again it is the competition among capitals, their indifference to and independence of one another, which brings it about that the individual capital relates to the workers of the entire remaining capital not as to workers: hence is driven beyond the right proportion. What precisely distinguishes capital from the master-servant relation is that the worker confronts him as consumer and possessor of exchange values, and that in the form of the possessor of money, in the form of money he becomes a simple centre of circulation – one of its infinitely many centres, in which his specificity as worker is extinguished. * * It is quite the same with the demand created by production itself for raw material, semi-finished goods, machinery, means of communication, and for the auxiliary materials consumed in production, such as dyes, coal, grease, soap, etc. This effective, exchange-value-positing demand is adequate and sufficient as long as the producers exchange among themselves. Its inadequacy shows itself as soon as the final product encounters its limit in direct and final consumption. This semblance, too, which drives beyond the correct proportion, is founded in the essence of capital, which, as will be developed more closely in connection with competition, is something which repels itself, is many capitals mutually quite indifferent to one another. In so far as one capitalist buys from others, buys commodities, or sells, they are within the simple exchange relation; and do not relate to one another as capital. The correct (imaginary) proportion in which they must exchange with one another in order to realize themselves at the end as capital lies outside their relation to one another. To begin with: capital forces the workers beyond necessary labour to surplus labour. Only in this way does it realize itself, and create surplus value. But on the other hand, it posits necessary labour only to the extent and in so far as it is surplus labour and the latter is realizable as surplus value. It posits surplus labour, then, as the condition of the necessary, and surplus value as the limit of objectified labour, of value as such. As soon as it cannot posit value, it does not posit necessary labour; and, given its foundation, it cannot be otherwise. It therefore restricts labour and the creation of value – by an artificial check, as the English express it – and it does so on the same grounds as and to the same extent that it posits surplus labour and surplus value. By its nature, therefore, it posits a barrier to labour and value-creation, in contradiction to its tendency to expand them boundlessly. And in as much as it both posits a barrier specific to itself, and on the other side equally drives over and beyond every barrier, it is the living contradiction. * * Since value forms the foundation of capital, and since it therefore necessarily exists only through exchange for counter-value, it thus necessarily repels itself from itself. A universal capital, one without alien capitals confronting it, with which it exchanges – and from the present standpoint, nothing confronts it but wage labourers or itself – is therefore a non-thing. The reciprocal repulsion between capitals is already contained in capital as realized exchange value.
https://www.marxists.org/archive/marx/works/1857/grundrisse/ch08.htm