*Engels is evidently referring to Volumes 2 and 3 here, although in this same Preface he goes on to refer to Theories of Surplus-Value as Volume 4 of Capital, and Marx had always seen ‘the history of the theory’ as an integral concluding part of his magnum opus. The drafting of Volume 2, however, was rather more protracted than Engels presents it here; he himself gives the full details of this in his Preface to Volume 2 (Pelican edition, pp. 83 ff.).

†In the present edition, all Engels’s substantial interpolations in the main body of the text are placed simply in parentheses and followed by his initials. This has not been done with his footnotes, but these too are always followed by his initials. Square brackets contain interpolations by the translator.