LEON WALRAS' CORRESPONDENCE AND RELATED PAPERS: THE BIRTH OF MATHEMATICAL ECONOMICS.

Léon Wairas' "Correspondence and Related Papers," edited by W. Jaffé is the source book on the birth of mathematical economics. He himself was first to succeed in breaching the wall of the scornful opposition to the application of mathematics to economics, only at the high cost of forty years of a much-resented exile and of endless struggles with this correspondence as a weapon. Still more important, "Correspondence" provides a fascinating example of the social process of discovery with feedbacks through colleagues engaged in similar endeavors. Such records are of special interest for those blessed periods in the history of a science when ideas have ripened to the point where several scientists discover the same things at the same time. This was certainly the case of economics around the 1870's when ten persons independently discovered marginal utility and its relation to relative prices, and around the 1880's when only a slightly smaller number of economists discovered the similar relation for marginal productivities.