This text looks at two questions in relation to the basis of the professional study of economics in the late 20th century. The author explores how the discipline came to be dominated by an approach that is so heavily dependent on mathematically derived models, and also what happened to the other approaches to the discipline which were deemed viable less than 50 years ago. Between the two world wars there were two well-accepted schools of thought in economics: the "neoclassical" which emerged in the last third of the 19th century, and the "institutionalist", which started with the works of Veblen and Commons at the end of the same century. Although the contributions of the institutionalists are nearly forgotten now, Yuval Yonay shows that their legacy lingers in the study and practice of economics today. By reconsidering their impact and by analyzing the conflicts which arose between neoclassicist and institutionalists, Yonay seeks to bring to life a "hidden" chapter in the history of economics. The author is a sociologist of science and brings this perspective to economic history. By utilizing the actor-network approach of Bruno Latour and Michel Callon, he arrives at an understand