Areal differentiation represents one of the classic philosophical approaches to geographic inquiry. Some of the earliest geographical scholars, including Strabo and Ibn Khaldun, sought to describe and catalog variations in the places and cultures they encountered, or were informed about by others.
Areal Differentiation Concept
A central concept of areal differentiation is that the surface of the earth may be divided into regions, which may be distinguished and categorized using various spatial criteria. Thus, areal differentiation provides the theoretical foundation for regional geography, by conceptualizing space as consisting of identifiable units that may be distinguished from one another on the basis of a set of phenomena or criteria.
For much of the historical development of geography as a science, this was the approach followed. Geographers partitioned the world as they encountered it into sections based on differences they codified, formulating these distinctions in a descriptive narrative designed to provide a sense of place. During the quantitative revolution, this view was derided by its fiercest critics as simplistic, static, and sterile, but in recent decades an emphasis on areal differentiation has reappeared in some subdisciplines of geography. For example, areal differentiation has offered a basis for new directions in human geography, especially postmodern analyses that focus on the social and cultural processes that construct a sense of place for a given location; and studies in the geography of economic development, which seek to conceptualize the forces and factors that result in uneven geography of economic and political activity, as well as the spatial variation between places in terms of the opportunities and conditions that results from such variation.
The most detailed modern explanation and vigorous defense of the perspective of areal differentiation were provided by Richard Hartshorne in his influential monograph, The Nature of Geography, published in 1939.
In this work Hartshorne argued that geography is based on a “chorographic point of view,” which distinguishes it from “systematic sciences,” and that geography “seeks to acquire a complete knowledge of the areal differentiation of the world. … ” Hartshorne closely correlates the study of geography with that of history, arguing that both must derive their basis from the integration of other scholarly sciences and philosophical approaches and that both are so-called “naı¨ve sciences,” meaning that they rely on describing phenomena as they actually exist in the world. Many of Hartshorne’s critics suggest that he is too dependent on the view of the “German School,” especially Carl Ritter, Friedrich Ratzel, and Alexander von Humboldt in his description of the evolution of geography, but his work remains a classic and is standard reading for students of the discipline.
In the second half of the 20th century, the perspective of areal differentiation was challenged by new methodologies and theories. The foremost of these was the evolution of locational analysis as a method of examining spatial phenomena, and the larger contextual approach of landscape analysis. Proponents of these new approaches held that areal differentiation was overly descriptive, lacked an integrative perspective, and limited geography to a narrow philosophical foundation that ignored the development of emerging statistical and mathematical methodologies. Nevertheless, areal differentiation continues to inform the scholarship of many geographers who study the distribution and interaction of human systems, and the perspective remains a cornerstone of geographical analysis and theory.