An interest in space or spaces may usually be classified according to the instinctual drive it chiefly represents. Mental or physical interest in exploration, measurement, or utilization are

sublimations, respectively, of oral incorporative, and obsessive, and phallic intrusive and erective attitudes. Clinical evidence is presented to demonstrate that, in one case, exploration pursued as an end in itself appeared to follow an orderly psychosexual sequence, with an initially predominating oral incorporative component. Such systematic explorers as Sven Hedin and the patient here studied are believed to proceed through a sequence of sublimated pregenital activities. Robinson Crusoe shows an intense oral fixation and for this reason his explorations were incomplete and inefficient. The psychological organization of space is a highly individual process but there are universally basic factors as shown by the literature on the subject and by experiences in group therapy.