Where appropriate, the extracts have been taken from the first edition of the particular work. Authorial footnotes, where retained, have been included in the endnotes; editorial footnotes are indicated by letter, and endnotes by number. In bibliographical references, the place of publication is London unless otherwise stated. As a matter of convenience we have used the capitalised phrase Political Economy to refer to the body of economic ideas which the Victorians themselves categorised under this label, though it should be borne in mind that, as the introductory essay points out, it was a label which obscured many differences among the classical economic writers. We are grateful to Professor R. D. C. Black for commenting upon an earlier draft of the introduction, though, of course, the responsibility for any remaining errors lies with us. Laurence and Wishart Ltd have kindly granted permission to reproduce material from their Marx and Engels Collected, Works.