New Worlds and Th eir Challenges 107key constraint operating on the papacy in its attempts to control trade with
Muslim lands: the fact that nonadherence to the Christian religion was sim-
ply not, per se, a violation of natural law. Consequently, non- Christians could
not be deprived of their natural- law rights on the ground of their status as
nonbelievers.
It was not too diffi cult to accept this principle in the case of Muslims, whose
civilization was highly developed— in many ways more advanced than that of
the Eu ro pe an Christians. Th e universalist outlook of natural law would, how-
ever, be subjected to a much greater challenge when Eu ro pe ans made contact
with other, more exotic cultures. Th e northeastern crusade had provided
some telling indications of problems that could arise. But even more serious
challenges lay ahead.Finding New Lands Abroad
By the end of the Middle Ages, Eu ro pe an expansion was going further afi eld
than ever before, with the Atlantic seaboard kingdoms of Spain and Portu-
gal taking the lead. As early as the fourteenth century, there was exploration
of the west coast of Africa, leading to the discovery of the Canary Islands.
Th e following century, Portuguese mariners ventured much further down
the African coast. Over a period of some forty years (1419– 60), about thirty-
fi ve expeditions sailed from Portugal (although only eight of them were
initiated by the famous Prince Henry the Navigator). Portugal even
founded settlements on islands far out in the Atlantic (Madeira in 1425 and
in the Azores in 1427). Contacts with African societies were not always
peaceful. Th ere were attacks, for example, by Portuguese knights against
unarmed fi shermen on the coast of Mauritania, as a result of which Prince
Henry forbade the use of force except in self- defense.
Somewhat later, Spain, too, became active in exploration. In 1492, the Ital-
ian mariner Christopher Columbus, sailing for Spain with the grand title of
Admiral of the Ocean Sea, made a landing in the West Indies and estab-
lished a settlement on the island of Hispaniola. Shortly aft er this, colonists
arrived on other West Indian islands. More spectacular by far were the con-
quests of the two great Indian empires of the American mainland, those of
the Aztecs (in 1519– 22) and the Incas (in 1533).