Four geography concepts illustrate the varied nature of the science and provide a pluralistic basis for uniting professional and pedagogical geography and for promoting communication with laymen. The spatial tradition, based on interest in geometry and movement, separates aspects of distance, form, direction, and position from events themselves. Ancient Greek sailing records first showed this perspective; school teachers and research geographers of central-place theory show it today. The second tradition, area studies, focuses on the nature and character of places, emphasizing literature and history. The academic community recognizes this second tradition, although technical vocabulary isolates professionals from lay teachers. The third tradition, the man-land interrelationship, initially had an environmental perspective and then changed to a cultural one. Today, its acceptance is seen in studies of resource use and conservation. Earth science, the fourth tradition, studies concrete aspects of the physical world. Although geology-based college courses overemphasize physical geography and some social studies curricula reject it, earth science does provide a unified view of the earth as man's habitat. (AV)