This paper discusses and develops an important distinction drawn by Jevons, viz . that between natural and fictitious quantities. This distinction provides a basis for a theory of economic concept formation that aims at picking out families of models that are phenomenally adequate, explanatory...

Investigates the economic methodologies of Carl Menger, William Stanley Jevons and Gustav Schmoller with respect to the issue of whether mathematics is or is not an adequate language to express economic relationships. First, Menger’s and Jevons’s respective methodologies are identified as...