The history of economics can be compared to a calm sea that once in a while happens to be shaken by heavy storms. This arises when works come out aimed at turning upside down the received interpretation of a great bygone economist's views. Professor Donald A. Walker's recent book, Walras's Market Models (1996), is likely to be among them. Its main thrust is that the view present-day economists have of Léon Walras is incorrect. The basic reason, he claims, is that to date all interpretations of Walras have been based on the last (posthumous) edition of the Eléments d' économie pure (henceforth the Elements), itself a slightly amended version of its fourth edition. To him this is a pity because Walras's most interesting theoretical ideas are to be found in its second and third editions—the embodiment of what he calls Walras's mature phase of theoretical activity—yet were abandoned by him when he revised his work for the fourth edition. The aim of Walker's book, then, is to bring to the fore the picture of what he considers to be the real Walras: an economist interested in the functioning of real-world markets and abiding by a realistic methodology who is attentive to the institutional set-up underlying his system of equations, and who is keen to provide his readers with disequilibrium models. In other words, Walker is trying to make the same claim apropos Walras as Axel Leijonhufvud (1968) did thirty years ago about Keynes when defending the view of a breach between the economics of Keynes and Keynesian economics. To Walker, modern Walrasian economics, or neo-Walrasian theory as it is more often called, is a betrayal of Walras's economics.