Central to the Marxist critique of political economy is the obscurantism of the juridical labour contract, between the worker and the capitalist, that masks the true, exploitive nature of their economic relationship—that the worker does not sell his and her labour, but that the worker sells individual labour power, the human capacity to perform work and manufacture commodities (goods and services) that yield a profit to the producer. The work contract is the mask that obscures the economic exploitation of the difference between the wages paid for the labour of the worker, and the new value created by the labour of the worker.