Recent articles have explored from different perspectives the psychological foundations of American institutionalism from its beginning to the interwar years (Hodgson 1999; Lewin 1996; Rutherford 2000a, 2000b; Asso and Fiorito 2003). Other authors had previously dwelled upon the same topic in their writings on the originsand development of the social sciences in the United States (Curti 1980; Degler 1991; Ross 1991). All have a common starting point: the emergence during the second half of the nineteenth century of instinct-based theories of human agency. Although various thinkers had already acknowledged the role of impulses and proclivities, it was not until Darwin's introduction of biological explanations into behavioral analysis that instincts entered the rhetoric of the social sciences in a systematic way (Hodgson 1999; Degler 1991). William James, William McDougall, and C. Lloyd Morgan gave instinct theory its greatest refinement, soon stimulating its adoption by those economists who were looking for a viable alternative to hedonism. At the beginning of the century, early institutionalists like Thorstein Veblen, Robert F. Hoxie, Wesley C. Mitchell, and Carleton Parker employed instinct theory in their analysis of economic behavior. Their attention wasdrawn by the multiple layers of interaction between instinctive motivation and intentional economic behavior. Debates on the role of instinctsin economicswere not confined to the different souls of American Institutionalism, and many more “orthodox” figures, like Irving Fisher or Frank Taussig, actively participated.

Léon Walras was a truly revolutionary economist. Not only did he leave a lasting mark on economic doctrine participating in the Marginalist Revolution, which supplanted the labor theory of value of the classical school, but he also contributed to major changes in economic methodology as being one of the first and most ardent promoters of the use of mathematics in economics. For an actor who played such a great role in the development of economics, how did he conceive his scientific endeavor? This question can be broken down into two different but related questions: First, how did he know that he had found true scientific laws? What was his theory of knowledge? Is it best described as empiricist (claiming that all knowledge comes from experience) or idealist (claiming that reason can achieve knowledge independently of experience)? And, second, what relation did his writings on pure theory bear with his policy prescriptions? Was there a normative bias in Léon Walras's methodology, i.e., were his positive statements molded by his normative inclinations?

This last set of questions has generated much debate, given that Walras actively fought for scientific rigor while not refraining from defending his views on the desired social order. For W. Jaffé, who unearthed his correspondence, a careful study of primary evidence shows that Walras's conception of justice heavily influenced his search for pure truth. The Éléments d'économie politique pure (Éléments), “appears, on the surface, as a competely wert-frei” system, but it is nevertheless “inform[ed]” by “implicit moral convictions” (Jaffé 1977, p. 371). However, D. A. Walker has strongly attacked Jaffe's allegation that Walras's theory of general equilibrium was deliberately constructed as a normative scheme, pointing to Walras's “careful distinctions between normative and positive subject matters” (Walker 1984, p. 466).

This paper critiques the way Alfred Marshall is presented in many histories of economic thought, in particular, the typical neglect of the relation of his economic theory and method to his public policy proposals and views on economic evolution. A good example is the textbook of Stanley L. Brue, The Evolution of Economic Thought, which is specifically policy oriented. He notes in his remarks on Marshall's life and method: “Marshall's thinking left room for cautious reform, that is, modest departures from laissez-faire” (2000, p. 295). But the only illustration of this is Marshall's discussion of the welfare effects of industry taxes and subsidies. However, even here Brue concludes (2000, p. 316) with a quote from Marshall: “These conclusions, it will be observed, do not by themselves afford a valid ground for government interference.”

For a long time, Marshall's chief contribution to economic science was considered to be Book V of Principles of Economics, which is the “analytic core” of his thought. Book V, “General Relations of Demand, Supply and Value,” deals with the important theme of economic equilibrium that ipso facto rules out any possibility of coping with economic development. When Alfred Marshall describes Book V, he points out that “it is not descriptive, nor does it deal constructively with real problems. But it sets out the theoretical backbone of our knowledge of the causes that govern value” (1961, vol. 1, p. 324); in short, it “deals with abstractions” (1898, p. 52). The existence of Book V has been supposed by some scholars to be sound enough proof that Alfred Marshall was not interested in the question of economic development. More recently, however, it has been suggested that one of the main Marshallian concerns was economic development,—“the high theme of economic progress,” as he called it (Marshall 1961, vol. 1, p. 461).

One of the very important components in the urban and agricultural land use model is the so-called bid-rent curve. Regional and urban economists, city planners, and economic geographers have used this curve extensively as an analytical device. It is generally accepted that the explicit bid-rent function was first applied to the equilibrium of land use patterns in agricultural production by August Losch (1954) in Germany and Edgar S. Dunn (1954) in America, and was later extended by William Alonso (1964).