conceptualize the forces and factors that result in an uneven geography of eco-
nomic 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 was 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 distin-
guishes it from “systematic sciences,” and that geography “seeks to acquire a com-
plete 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 philosophi-
cal 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 Hart-
shorne’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 oflocational analysisas a method of examining spatial phenomena,
and the larger contextual approach of landscape analysis. Proponents of these new
Areal Differentiation 17Alexander von Humboldt (1769–1859)
Humboldt was the scion of a wealthy Prussian family. He was university educated with a wide
range of interests. Of greatest importance was his economic freedom to travel bringing meas-
urement instrumentation with him. His careful measurements and splendid write-ups are
considered precedent setting in terms of modern, scientific geography. He traveled to Europe,
Russia, Central America, and South America and was a mainstay on expeditions of the early
1800s on which his diverse experiences included exploring the Orinoco River, climbing
Andean volcanoes, and measuring temperature and velocity in the Peru Current. He then
lived in Paris where he published 30 volumes (1805–1834) about his studies in the Americas.
His works covered many geographic themes including landforms, plant geography, and
climate, and he was celebrated as one of the leading intellectuals of the age. In 1827 he moved
to Berlin and became chamberlain to the Prussian king where he continued his pursuits with
such projects as the first temperature map of the world. His last work,Kosmos,integrated
his ideas about the world in a series of five volumes and was immediately considered to be
the best world scientific work ever written. Alexander’s brother, Wilhelm, founded the
University of Berlin in 1810 and it was renamed Humboldt-Universita ̈t to honor both men.