The army that enforced the Pax Romana had expanded little beyond the size envisaged for it by Augustus, despite the enlargement of the empire by Claudius, the Flavians, and Trajan. It reached 31 legions momentarily under Trajan, but it usually numbered 28 under the Flavians and Antonines until the onset of the frontier crisis in Aurelius’ reign brought it to 30. Without raising pay rates to attract recruits more easily, a large force was seemingly beyond reach—which probably explains why Hadrian, and later Commodus, halted further expansion.
The army was used not to prop up a militarist government but to defend the frontiers. Shifts in enemy pressures, however, caused the legions to be distributed differently than in Julio-Claudian times. Under Antoninus Pius, the Danubian provinces (Pannonia, Moesia, Dacia) had 10, and the East (Anatolia, Syria, Palestine, Egypt) had 9, and both regions also had supporting naval flotillas; of the remaining 9 legions, Britain contained 3 and the Rhineland 4. Tacitus in his Annals (4.5) rates the auxiliary troops near the turn of the era as being about as numerous as the legionaries. But they soon outnumbered them: that is, whereas legions contained somewhat more than 5,000 men each if they were at full strength and thus totaled roughly 150,000 in the mid-2nd century, the auxiliaries numbered 245,000—again, if at full strength. Recent estimates put the actual figure for the entire army at 375,000 to 400,000.
Two reasons, military and financial, explain the growing use of nonlegionaries. Mustered in units mostly of 500, they were easier to move around and could be encouraged to maintain the special native skills of their inheritance—as slingers from the Balearic Islands or Crete, in camel corps from Numidia, or as light cavalry from Thrace. In addition, they could be recruited for lower wages than legionaries. As regards recruitment for the legions, even that higher rate proved less and less attractive. Whereas legions in the early empire could be largely filled with men born in Italy and southern Gaul, by the second half of the 1st century most of the men had to be drawn from the provinces; after Trajan, they were largely natives of the frontier provinces. Young men from the inner parts of the empire, growing up in successive generations of continual peace, no longer looked on military service as a natural part of manhood, and the civilian economy appeared attractive compared to the rewards at some frontier posting. Peace and prosperity thus combined to make the army less and less Roman, less and less of the centre, and more and more nearly barbarous.
The troops’ loyalty did not suffer on that account. The men were no more ready to mutiny or to support a pretender around ad 200 than they had been in the early empire. However, experience especially in the year of the four emperors (ad 69) did suggest the desirability of splitting commands into smaller units, which, in turn, involved splitting up provinces, the number of which was constantly growing; by Hadrian’s day subdivision began to anticipate the fragmentation later carried out by Diocletian. Cultural life
The literature of the empire is both abundant and competent, for which the emperors’ encouragement and financing of libraries and higher education were perhaps in part responsible. The writers, however, with the possible exception of Christian apologists, were seldom excitingly original and creative. As Tacitus said, the great masters of literature had ceased to be. Perhaps Augustus’ emphasis on tradition affected more than political ideals and practice. At any rate, men of letters, too, looked often backward. At the same time, they clearly reveal the success of the empire in spreading Greco-Roman culture, for the majority of them were natives of neither Italy nor Greece. Of the writers in Latin, the two Senecas, Lucan, Martial, Columella, Hyginus, and Pomponius Mela came from Spain; Fronto, Apuleius, and probably Florus and Aulus Gellius, from Africa. Tacitus was perhaps from Gallia Narbonensis. The Latin writers in general sought their models less in Greece than in Augustus’ Golden Age, when Latin literature had reached maturity. Thus, the poets admired Virgil and imitated Ovid; lacking genuine inspiration, they substituted for it an erudite cleverness, the fruit of an education that stressed oratory of a striking but sterile kind. Authentic eloquence in Latin came to an end when, as Tacitus put it, the principate “pacified” oratory. Under the Flavians and Antonines, an artificial rhetoric, constantly straining after meretricious effects, replaced it. The epigrammatic aphorism (sententia) was especially cultivated; the epics of Lucan, Valerius Flaccus, Silius Italicus, and Statius are full of it, and it found a natural outlet in satirical writing, of which the Latin instinct for the mordant always ensured an abundance. In fact, Latin satire excelled: witness Martial’s epigrams, Petronius’ and Juvenal’s pictures of the period, and Persius’ more academic talent. For that matter, Tacitus’ irony and pessimism were not far removed from satire.
In the East the official status of Greek and the favour it enjoyed from such emperors as Hadrian gave new life to Greek literature. It had something in common with its Latin counterpart in that it looked to the past but was chiefly written by authors who were not native to the birthplace of the language. The so-called Second Sophistic reverted to the atticism of an earlier day but often in a Roman spirit; its products from the Asian pens of Dio Chrysostom and Aelius Aristides are sometimes limpid and talented tours de force but rarely great literature. In Greek, too, the best work was in satire, the comic prose dialogues of the Syrian Lucian being the most noteworthy and original literary creations of the period. Among minor writers the charm of Arrian and Pausanias, Asians both, and above all of Plutarch abides (although Plutarch’s talents were mediocre, and his moralizing was shallow, his biographies, like those of his Latin contemporary Suetonius, are full of information and interest).
Imperial encouragement of Greek culture and a conviction, no longer justified, of its artistic and intellectual superiority caused the East to resist Latinization. This attitude was bound to lead to a divided empire, and thoughtful observers must have noted it with misgivings. The split, however, was still far in the future. Meanwhile, there was a more immediate cause for disquiet. The plethora of summaries and anthologies that appeared implies a public progressively indifferent to reading whole works of literature for themselves. In other words, the outlook for letters was poor, and this had an unfortunate effect on the scientific literature of the age, which was in itself of first-class quality. Dioscorides on botany, Galen on medicine, and Ptolemy on mathematics, astronomy, and geography represent expert scholars expounding carefully, systematically, and lucidly the existing knowledge in their respective fields. But their very excellence proved fatal because, as the reading public dwindled, theirs remained standard works for far too long; their inevitable errors became enshrined, and their works acted as brakes on further progress.
Stoicism was the most flourishing philosophy of the age. In the East a sterile scholasticism diligently studied Plato and Aristotle, but Epictetus, the stoic from Anatolia, was the preeminent philosopher. In the West, stoicism permeates Seneca’s work and much of Pliny’s Natural History. Evidently, its advocacy of common morality appealed to the traditional Roman sense of decorum and duty, and its doctrine of a world directed by an all-embracing providence struck a responsive chord in the 2nd-century emperors, though they deeply disapproved of its extremist offshoots, the cynics: Marcus Aurelius, as noted, was himself a stoic.
Imperial art, dealing above all with man and his achievements, excelled in portraits and commemoration of events; Roman sculpture and presumably Roman painting, also, owed much to Greek styles and techniques. It emerged, however, as its own distinctive type. The Augustan age had pointed the way that Roman art would go: Italian taste would be imposed on Hellenic models to produce something original. The reliefs of the Augustan Ara Pacis belong to Rome and Italy, no matter who actually carved them. By Flavian times this Roman artistic instinct had asserted itself and with it the old Roman tendency toward lively and accurate pictorial representation. It can be seen from the reliefs illustrating the triumph over Judaea in the passageway of the Arch of Titus in the Roman Forum. The narrative description dear to Roman art found its best expression in the great spiral frieze on Trajan’s Column, where the emperor can be seen among his soldiers at various times in the Dacian campaigns; the story of the war plays a most important part, although, like most imperial monuments, the column is meant to exalt the leader. Under Hadrian a reaction made sculpture less markedly Italian, as if to be in conformity with the slow decline of Italy toward quasi-provincial status. Also under Hadrian, the figure of the emperor was more prominent—bigger and more frontal than the other figures—as if to illustrate the growing monarchical tone of the principate. This tendency continued under the Antonines, when there was a magnificent flowering of sculpture on panels, columns, and sarcophagi; but its exuberance and splendour foreshadow the end of classical art.