An empire is a state formed by the rule of one state over other states. It is immaterial in this connection what form of government the ruling people prefers. Power may be exercised there by a monarchy, an oligarchy, or a majority without altering in any essential the relation of the sovereign to its dependencies. Still less does it matter whether the subject people is governed by the one, the few, or the many; for all kinds of governments may exist, and have existed, in dependencies.
Naturally, an empire is compatible with any kind of an administrative service among both governors and governed. The suzerain may attend to its affairs with the aid of professional and specially trained officials, as in a bureaucracy; and a vassal may entrust the details of its public business to successive fractions of its citizens, as in some republics: no imperial relation is established unless separate states or parts of states are involved. But when these are related in a whole as superiors and inferiors, an empire at once arises.
The relation of inferiority and superiority is, however, essential in any empire. In modern times this is acknowledged with the utmost frankness. Upon the higher capacity for government claimed by the Christian peoples, the Western cultures, or the Anglo-Saxons, as the case may be, modern pride, greed, or conscience bases its right to control inferior races. "Take up the white man's burden" is the modern substitute for the ancient commandment, "Go ye into all the world and preach the Gospel to every creature." The possession of a better rule of public life imposes—it is affirmed—a missionary obligation no less weighty than the possession of a special rule of eternal life.
Less exasperating, perhaps, than this assumption of moral and political superiority is the candid profession of the right of the stronger. The right of conquest gives a title which is valid in international law when every other right is lacking. When superiority is stipulated to be absent, the product is a federation or something similar from which the name empire is withheld. When, in course of time, superiority dies out till a common right eventually embraces subject and sovereign alike, a new state arises, to which, as in the case of the present-day British world, the title empire is applied with some impropriety.
There is, however, still another kind of empire. In it the superior authority is not a people, but an individual. He is called an emperor, and his family a dynasty. His authority is bestowed, as the present German Emperor said at Königsberg in 1910, not by "parliaments, and meetings, and decisions of the peoples, but by the grace of God alone." He is "a chosen instrument of Heaven," to speak with the same high authority, and "goes his way without regard to the views and opinions of the day." An emperor, thus defined, is not properly a part of his state at all. He stands outside of it, and is equal or superior to it. He is a state unto himself; and his jurisdiction is not domestic but imperial, in that he exercises dominion over another state. L'état c'est moi is an imperfect definition of this kind of empire, however; for it presumes the absence of political organization and activity among the subjects of the emperor. It presumes the permanency of the condition of absolute surrender (deditio) which, with the Romans, prefaced the work of restoration—the reëstablishment of civil rights within an enlarged state. In actual experience, moreover, a complete autocracy never exists. The will of every emperor is bound by the legislation which he has himself enacted, or accepted with the throne from his predecessor. If responsible to nothing else, he is responsible to his own past. He may withdraw his charters: he cannot violate them with impunity.
The policy by which a people or an autocrat acquires and maintains an empire, we call imperialism. The term is, of course, a legacy from Rome—a mute witness to the peculiar importance of the Roman empire in the history of state-building. And, I suppose, it is the policy of Rome that we think of most instinctively when we allude to imperialism. This is by no means an accident. For not simply the type, but also many of the most noteworthy varieties of this kind of policy, are found in the experience of the Romans; and the course of political progress has been such that in the triumph of Rome imperialism reached its logical issue more closely than either before or since in the history of the world.
For the logical issue of a thorough-going imperial policy—one in which the possession of physical ability may be presupposed—is the formation of an universal empire. And, in fact, the two most powerful and ardent imperialists of antiquity, Alexander the Great and Julius Cæsar, aimed to include in their dominions the entire inhabitable world. This issue was, however, never more nearly reached than in the long period before and after the Christian era during which only shifting nomads and intractable Parthians disputed successfully the will of the Roman Senate and the orders of the Roman emperors. For five hundred years after the triumph of Constantine the universality of the Roman empire was as mandatory in men's thinking as was the catholicity of the Christian Church. "There are many 'empires' in the world to-day," says Professor Bury[1] in explaining the coronation of Charlemagne in 800 A.D., "but in those days men could only conceive of one, the Roman imperium, which was simple and indivisible; two Roman empires were unimaginable. There might be more than the one emperor; but these others could only be legitimate and constitutional if they stood to him in a collegial relation." How thoroughly the Romans impressed the concept of universality upon the term empire may be judged by the fact that, in the face of all realities, the Frankish monarchs at Aachen and the Greek kings at Constantinople ruled as colleagues a Roman empire which stretched from the borders of Armenia to the shores of the Atlantic.