Alfred Marshall (1842-1924), was one of the leading figures in the development of economics and the founder of the Cambridge School of Economics. Upon its original release in 1996, this three-volume set filled a long-standing gap in the history of economic thought with hitherto unpublished material. Students will find it a basic resource for understanding the development of economics and other social sciences in the period since 1870. In particular, it provides much new information about Marshall's views on economic, social and political issues, his struggles to promote the teaching of economics at the University of Cambridge, and his relations with colleagues in Cambridge and elsewhere. Marshall's letters are notable for their frankness and spontaneity.