In the previous chapter, we studied what Marx had termed the ‘process of production of capital’. Using the key concept of surplus value, we saw that the process of production of capital involved two aspects (or steps): the generation of surplus value by capital in the first step, and, in the next, the accumulation of surplus value to create capital. This argument was developed by Marx in Volume 1 of Capital, and that had been the main object of our study in the previous chapter. We had also noted that in developing this argument, Marx had abstracted from two important issues: (a) how did the commodities find a market? and (b) how did the material underpinnings of the capital accumulation process get recreated over and over again?

The fact that Marx had abstracted from these two questions was consistent with his method of presentation – of moving from the abstract to the concrete. Once the analysis of the process of production of capital was completed in Volume I, Marx returned to these questions in Volume II and took up the issue of realization of surplus value. Since surplus value is realized only through sale of commodities, and since sale of commodities occur in what Marx calls the ‘sphere of circulation’, the analysis in Volume II begins with an investigation of ‘formal and material changes undergone by capital in the circulation sphere’. Marx studies some general issues relating to the sphere of circulation and to the circulation of capital as a way to set-up the framework for the analysis of the problems of realization of surplus value – the main question investigated in Volume II of Capital.