This law of the modern world, that power tends to expand indefinitely, and will transcend all barriers, abroad and at home, until met by superior forces, produces the rhythmic movement of History. Neither race, nor religion, nor political theory has been in the same degree an incentive to the perpetuation of universal enmity and national strife. The threatened interests were compelled to unite for the self-government of nations, the toleration of religions, and the rights of men. And it is by the combined efforts of the weak, made under compulsion, to resist the reign of force and constant wrong, that, in the rapid change but slow progress of four hundred years, liberty has been preserved, and secured, and extended, and finally understood. II THE NEW WORLD GREATER CHANGES than those which were wrought by governments or armies on the battlefield of Italy were accomplished at the same time, thousands of miles away, by solitary adventurers, with the future of the world in their hands. The Portuguese were the first Europeans to understand that the ocean is not a limit, but the universal waterway that unites mankind. Shut in by Spain, they could not extend on land, and had no opening but the Atlantic. Their arid soil gave little scope to the territorial magnate, who was excluded from politics by the growing absolutism of the dynasty, and the government found it well to employ at a distance forces that might be turbulent at home. The great national work of exploration did not proceed from the State. The Infante Henry had served in the African wars, and his thoughts were drawn towards distant lands. He was not a navigator himself; but from his home at Sagres, on the Sacred Promontory, he watched the ships that passed between the great maritime centre at the mouth of the Tagus and the regions that were to compose the Portuguese empire. As Grandmaster of the Order of Christ he had the means to equip them, and he rapidly occupied the groups of islands that lie between Africa and mid Atlantic, and that were a welcome accession to the narrow territory of Portugal. Then he sent his mariners to explore the coast of the unknown and dreaded continent. When they reached the Senegal and the Gambia, still more, when the coast of Guinea trended to the East, they remembered Prester John, and dreamed of finding a way to his fictitious realm which would afford convenient leverage for Christendom, at the back of the dark world that faced the Mediterranean.