Marx began to write Theories of Surplus Value within the framework of the original plan of his Critique of Political Economy as he had projected in 1858–62. On the basis of what Marx says about the structure of his work in his introduction to the first part of A Contribution to the Critique of Political Economy, in his letters of 1858–62 and in the 1861–63 manuscript itself, this plan can be presented in the following schematic form: