The expansion of Western Europe after the fifteenth century brought sweeping changes in aboriginal populations; the formation of new, mixed ones; the development of new trade routes and commerce; the erosion of old cultures; and the creation of new states and political forms. Anthony Pagden’s book concentrates on the various theories that emerged to defend or question that expansion, mostly those treating America and almost all appearing in Spain, France, and England. The three centuries covered were characterized by European settlement in overseas possessions, whereas later European imperialism aimed essentially at economic exploitation.

In the sixteenth and seventeenth centuries, the theories concentrated on the legitimacy of sovereignty in America, the right to titles, and the rights of natives. Many of the Spanish authorities Pagden discusses are familiar to Latin Americanists, among them Vitoria, Soto, Las Casas, Seaveda, Fajardo, and Solórzano Pereira. French and English writers’ arguments, by denying most of the Spanish claims, had a simpler task. The most unusual Spanish writers opposed overseas expansion: Covarrubias y Leyva held that such vast areas were impossible to govern; Vázquez de Menchaca declared that even conquest could not create natural lordship, so overseas dominions were unnatural. The most extreme European writers, among them some Calvinists, resorted to the theory of res nullis. As non-Christians, the natives had no rights.

By the end of the seventeenth century and into the early eighteenth, the reduction of Spains foreign dominions to its non-European territories changed the terms of the European debate. The discussion centered henceforth on what had gone wrong in Spain’s affairs. English and French writers found the causes in the Spanish emphasis on mining and ideas of grandeur; the true basis of wealth was agriculture and commerce, as in the British and French colonies. Their ideas entered Spanish thinking in such treatises as that of Campillo y Cossío and became embodied in the Bourbon reforms. In the last quarter of the century, the American Revolution added a new note: it demonstrated that the development of sizable European populations overseas meant their eventual independence from the home country.

Two final chapters deal with the calculation of the benefits and losses brought by overseas expansion. That discussion emphasized the costs of overextension, the condemnation of slavery, a kind of cultural relativism, and the idea of confederation. Pagden obviously favors this idea for world organization today, calling it the ancient Greek model, but warns that even though the United States is a stable federation, abroad it imposes its own ideas of proper economic and financial conduct, a new imperialism returning to the Roman concept of a common model.