In his discussion of surplus capital in Notebook IV, Marx writes:
All moments which confronted living labour capacity, and employed it as alien, external powers, and which consumed it under certain conditions independent of itself, are now posited as its own product and result. … This new value which confronts living labour as independent, as engaged in exchange with it, as capital, is the product of labour. (p. 451)
This reads a bit like a “You asked for it!” to the worker, who is supposed to realize that he has forged the chains by which he is bound and is forging new chains for his comrades. The worker will recall a traumatic event that he has repressed, namely the moment when he gave birth to his master.
He has produced not only the alien wealth and his own poverty, but also the relation of this wealth as independent, self-sufficient wealth, relative to himself as the poverty which this wealth consumes, and from which wealth thereby draws new vital spirits into itself, and valorizes itself anew.
In other words, the main product of living labour is the constitutive poverty of the working class.
It no longer seems here … as if capital, for its part, brought with it any value whatever from circulation. Rather, the objective conditions of labour now appear as labour’s product … (p. 453)
Here, although the thrust is the same as before, there is a more encouraging implication: You workers thought that the material preconditions for your productive activity came from the capitalist, that the capitalist gave you what you needed to produce your means of subsistence, and that you depend on him. “But we don’t need no damn capitalist!” they are supposed to exclaim in unison. This is one version of proletarianization: the acceptance of the fundamental and absolute poverty that defines you as pure potential, and the realization that you need nothing from the capitalist. The notion that the capitalist needs the worker but the worker doesn’t need the capitalist is only the first step. The more radical premise asserted by the proletarian is that he needs nothing.