Although the term "interdisciplinary" has come into general use only during the last fifty years, 1 as an idea it is contemporaneous with the growth of specialization. Webster's dictionary defines interdisciplinary as "involving two or more academic disciplines," 2 and other dictionaries agree. The imprecision of this definition reflects the imprecision with which the term is usually employed. It has been a catchall word used to describe any kind of mixing of disciplines. Sophisticated educators prefer to reserve it for interaction between two or more disciplines, which may range from communication of ideas to the mutual integration of organizing concepts, methodology, procedures, epistemology, data, and organization of research and education. Interaction is crucial; the mere juxtaposition of disciplines is properly described as multidisciplinary rather than interdisciplinary. Successful interdisciplinary activity usually leads to something more. The whole is greater than the sum of its parts. This meta-interdisciplinarity is usually called transdisciplinary and means that a common system of axioms for a set of disciplines has been established. 3
The practice of interdisciplinarity, in an unspecific sense, is as old as human thought. The Greeks regarded knowledge as a unified whole, an attitude that survived into the modern period, even though the unifying concepts changed. Education remained unspecialized, and learned men were scholars first, not mathematicians, political scientists, or historians. One individual could make substantive contributions in different areas.
All this changed during the nineteenth century; first in Germany, then in other Western countries, higher education was reorganized. New scientific subjects, such as chemistry and engineering, became topics for academic instruction; the humanities differentiated themselves; and the various areas of the social sciences emerged. No longer did all students study the same things; they pursued different courses of learning. When they became mature scholars, they were specialists, not generalists. An exact date cannot be assigned to the