The Open Society and Its Enemies (Princeton Classics)

by Karl Popper

The next idea, that of the theory of surplus value, is nearly as simple. It too was adapted by Marx from his predecessors. (Engels asserts11—perhaps mistakenly, but I shall follow his presentation of the matter—that Marx’s main source was Ricardo.) The theory of surplus value is an attempt, within the limits of the labour theory of value, to answer the question: ‘How does the capitalist make his profit?’ If we assume that the commodities produced in his factory are sold on the market at their true value, i.e. according to the number of labour hours necessary for their production, then the only way in which the capitalist can make a profit is by paying his workers less than the full value of their product. Thus the wages received by the worker represent a value which is not equal to the number of hours he has worked.