I Introduction: Franz Oppenheimer, the Physician Turned Economist THE IDEA OF scholarly synthesis was central to the founders of the American Journal of Economics and Sociology. (1) Franz Oppenheimer (1864-1943) in fact impersonated the idea of scholarly synthesis. Being the son of a Reformist rabbi these religious roots provided the impulse for his work he started out as a physician in the industrial suburbs of Berlin; his diagnosis was that he faced and not medical disease, which consequently brought him to the study of economics. But unlike many mainstream economists today, he insisted on the necessary cooperation between economists and sociologists, ideally in one person. His chair in Frankfurt, showing his own handwriting, was denominated for economic theory and sociology. In this article, I show his contributions with respect to economic aspects of health. These are not well known. Part of the reason is that the field of health economics as it is taught now is very narrow. Therefore, Oppenheimer's health economic contributions tend to be overlooked. Franz Oppenheimer was born 1864 in Hanover; the family later moved to Berlin, where his father was a Reformist rabbi. (2) Oppenheimer became a physician, but as he noted in his autobiography, this was an increasingly frustrating experience. He described that he often was not able to treat tuberculosis patients, despite a method of treatment available, because he was not able to keep them out of a health endangering job for a period long enough so that their health would be completely restored; he often could not help infants, who died because they received spoilt milk or were kept in overly heated and crowded rental quarters. (1929, op. cit., p. 77). Oppenheimer realized early in his practice how important economic, environmental, and circumstances were for people's health. (3) Oppenheimer practiced medicine for 10 years, before he decided rather abruptly to switch the approach, but not the basic preoccupation. While hiking in the Harz Mountains one night, the basic idea of his work struck him like a flash of lightning. The land rent operates like a lock on economic development (Bodensperre). (4) Any social ill that he diagnosed in society, he ultimately traced back to the lock of the land rent. His new area of research became the state sciences, in particular economics and sociology. In 1909, he received in Berlin his habilitation at the behest of Schmoller and Wagner by the faculty of the humanities for both economics and sociology. He himself used to emphasize that his field was economic and sociological theory. In 1919, he accepted a call to the chair of sociology and economics in Frankfurt. He left the chair in 1929 and went back to Berlin in order to establish his projects of cooperative agricultural settlements (Siedlungsgenossenschaften), which he proposed as the basis for a healthy life. After the National-Socialists came to power, he published in Amsterdam, but did not leave Germany until 1938, when he emigrated via Japan and Shanghai to the United States. In 1941, he was among the founding members of the American Journal of Economics and Sociology. Based on the synthesis of economics, sociology, and philosophy, he wanted to develop a theory that would then serve as the basis of reform. By changing the environment of men, Oppenheimer proposed to solve and political problems. (5) Oppenheimer died in Los Angelos in 1943. (6) The experience as a physician left an imprint on Oppenheimer's work in economics and sociology. In his autobiography, he also mentioned important precursors: So I came to my real profession with completely clear concepts of the natural sciences, of the structure and functioning of a higher organism in health and illness; and here I found the leading thoughts for my work of life. This becomes even obvious to someone, who is only slightly familiar with my work. …