It was an ancient tradition, that when the Capitol was founded by one of the Roman kings, the god Terminus (who presided over boundaries, and was represented, according to the fashion of that age, by a large stone) alone, among all the inferior deities, refused to yield his place to Jupiter himself. A favorable inference was drawn from his obstinacy, which was interpreted by the augurs as a sure presage that the boundaries of the Roman power would never recede. 22 During many ages, the prediction, as it is usual, contributed to its own accomplishment. But though Terminus had resisted the Majesty of Jupiter, he submitted to the authority of the emperor Hadrian. 23 The resignation of all the eastern conquests of Trajan was the first measure of his reign. He restored to the Parthians the election of an independent sovereign; withdrew the Roman garrisons from the provinces of Armenia, Mesopotamia, and Assyria; and, in compliance with the precept of Augustus, once more established the Euphrates as the frontier of the empire. 24 Censure, which arraigns the public actions and the private motives of princes, has ascribed to envy, a conduct which might be attributed to the prudence and moderation of Hadrian. The various character of that emperor, capable, by turns, of the meanest and the most generous sentiments, may afford some color to the suspicion. It was, however, scarcely in his power to place the superiority of his predecessor in a more conspicuous light, than by thus confessing himself unequal to the task of defending the conquests of Trajan.
The martial and ambitious of spirit Trajan formed a very singular contrast with the moderation of his successor. The restless activity of Hadrian was not less remarkable when compared with the gentle repose of Antoninus Pius. The life of the former was almost a perpetual journey; and as he possessed the various talents of the soldier, the statesman, and the scholar, he gratified his curiosity in the discharge of his duty.
Careless of the difference of seasons and of climates, he marched on foot, and bare-headed, over the snows of Caledonia, and the sultry plains of the Upper Egypt; nor was there a province of the empire which, in the course of his reign, was not honored with the presence of the monarch. 25 But the tranquil life of Antoninus Pius was spent in the bosom of Italy, and, during the twenty-three years that he directed the public administration, the longest journeys of that amiable prince extended no farther than from his palace in Rome to the retirement of his Lanuvian villa. 26
Notwithstanding this difference in their personal conduct, the general system of Augustus was equally adopted and uniformly pursued by Hadrian and by the two Antonines. They persisted in the design of maintaining the dignity of the empire, without attempting to enlarge its limits. By every honorable expedient they invited the friendship of the barbarians; and endeavored to convince mankind that the Roman power, raised above the temptation of conquest, was actuated only by the love of order and justice. During a long period of forty-three years, their virtuous labors were crowned with success; and if we except a few slight hostilities, that served to exercise the legions of the frontier, the reigns of Hadrian and Antoninus Pius offer the fair prospect of universal peace. 27 The Roman name was revered among the most remote nations of the earth. The fiercest barbarians frequently submitted their differences to the arbitration of the emperor; and we are informed by a contemporary historian that he had seen ambassadors who were refused the honor which they came to solicit of being admitted into the rank of subjects. 28
The terror of the Roman arms added weight and dignity to the moderation of the emperors. They preserved peace by a constant preparation for war; and while justice regulated their conduct, they announced to the nations on their confines, that they were as little disposed to endure, as to offer an injury. The military strength, which it had been sufficient for Hadrian and the elder Antoninus to display, was exerted against the Parthians and the Germans by the emperor Marcus. The hostilities of the barbarians provoked the resentment of that philosophic monarch, and, in the prosecution of a just defence, Marcus and his generals obtained many signal victories, both on the Euphrates and on the Danube. 29 The military establishment of the Roman empire, which thus assured either its tranquillity or success, will now become the proper and important object of our attention.
In the purer ages of the commonwealth, the use of arms was reserved for those ranks of citizens who had a country to love, a property to defend, and some share in enacting those laws, which it was their interest as well as duty to maintain. But in proportion as the public freedom was lost in extent of conquest, war was gradually improved into an art, and degraded into a trade. 30 The legions themselves, even at the time when they were recruited in the most distant provinces, were supposed to consist of Roman citizens. That distinction was generally considered, either as a legal qualification or as a proper recompense for the soldier; but a more serious regard was paid to the essential merit of age, strength, and military stature. 31 In all levies, a just preference was given to the climates of the North over those of the South: the race of men born to the exercise of arms was sought for in the country rather than in cities; and it was very reasonably presumed, that the hardy occupations of smiths, carpenters, and huntsmen, would supply more vigor and resolution than the sedentary trades which are employed in the service of luxury. 2 After every qualification of property had been laid aside, the armies of the Roman emperors were still commanded, for the most part, by officers of liberal birth and education; but the common soldiers, like the mercenary troops of modern Europe, were drawn from the meanest, and very frequently from the most profligate, of mankind.
That public virtue, which among the ancients was denominated patriotism, is derived from a strong sense of our own interest in the preservation and prosperity of the free government of which we are members. Such a sentiment, which had rendered the legions of the republic almost invincible, could make but a very feeble impression on the mercenary servants of a despotic prince; and it became necessary to supply that defect by other motives, of a different, but not less forcible nature — honor and religion. The peasant, or mechanic, imbibed the useful prejudice that he was advanced to the more dignified profession of arms, in which his rank and reputation would depend on his own valor; and that, although the prowess of a private soldier must often escape the notice of fame, his own behavior might sometimes confer glory or disgrace on the company, the legion, or even the army, to whose honors he was associated. On his first entrance into the service, an oath was administered to him with every circumstance of solemnity. He promised never to desert his standard, to submit his own will to the commands of his leaders, and to sacrifice his life for the safety of the emperor and the empire. 33 The attachment of the Roman troops to their standards was inspired by the united influence of religion and of honor. The golden eagle, which glittered in the front of the legion, was the object of their fondest devotion; nor was it esteemed less impious than it was ignominious, to abandon that sacred ensign in the hour of danger. 34 These motives, which derived their strength from the imagination, were enforced by fears and hopes of a more substantial kind. Regular pay, occasional donatives, and a stated recompense, after the appointed time of service, alleviated the hardships of the military life, 35 whilst, on the other hand, it was impossible for cowardice or disobedience