[The theories once current as to ancient knowledge of prophylactics in the shape of perfumes and the habitual use of woollen clothing may be dismissed as fanciful. The rational conclusion is that the early races developed a relative immunity, which was possessed neither by the eastern stocks imported in the period of conquest nor by the later invading Teutons. It is noteworthy, however, that at all times the dwellers in the tainted areas learned something of the necessary hygiene. See Dureau de la Malle, as cited. His investigation is interesting as showing how, in the early decades of the nineteenth century, long before Pasteur, biology had reached the perception that fevers come of an organic infection. It was doubtless such knowledge that led the Romans to burn their dead.]
There remains the question, What is the precise economic statement of the final collapse? It is easy to figure that in terms of (a) increasing barbarian enterprise, stimulated by the personal experience of the many barbarians who served the Empire, and of (b) increasing moral weakness on the part of the whole administrative system. And doubtless this change in the balance of military energy was decisive. When utter weaklings sat by heredity in the imperial chair, at best contemptuously tolerated by their alien officers, the end was necessarily near. The most incurable disease of empire was just empire; ages of parasitism had made the Roman ruling class incapable of energetic action; and the autocracy had long withheld from citizens the use of arms. But the long subsistence of the Eastern Empire as contrasted with the Western proves that not only had the barbarians an easier task against Italy in terms of its easiness of invasion, but the defence was there relatively weaker in terms of lack of resources. This lack has been wholly or partly explained by quite a number of writers[218] as a result of a failure in the whole supply of the precious metals—a proposition which may be understood of either a falling-off in the yield of the mines or a general withdrawal of bullion from the Empire. It is difficult to see how either explanation can stand. There was already an immense amount of bullion in the Empire, and a general withdrawal could take place only by way of export to the barbarian east in return for commodities.[219] But the eastern provinces of the Empire were still in themselves abundantly productive, and after the fall of Rome they continued to exhibit industrial solvency. No doubt the plunder of Rome by Alaric (409-10) greatly crippled the west, and the loss of Gaul and Spain was worse; but while the Empire retained Africa it had a source of real revenue. The beginning of the end, or rather the virtual end, came with the conquest of the African province by the Vandals (430-40). In 455 came the sack of Rome by the Vandals, whereafter there remains only a shadow of the Roman Empire, till Odoaker, dismissing Augustulus, makes himself king of Italy.
As for the falling-off in the yield of the Spanish mines, to which some writers seem to attribute the whole collapse, it could only mean that the Roman Government at length realised what had been as true before and has been as true since, that all gold-mining, save in the case of the richest and easiest mines, separately considered, or of groups of mines which have been acquired at less cost than went to find and open them, is carried on at a loss as against the standing competition of the great mass of precious metal above-ground at any moment, the output of unknown barbarian toil and infinite slave labour, begun long before the age of written history.[220] When it was reluctantly realised that the cost of working either the gold or the silver mines was greater to the State than their product,[221] they would be abandoned; though under a free government private speculators would have been found ready to risk more money in reopening them immediately. As a matter of fact, the Spanish mines were actually worked by the Saracens in the Middle Ages, and have been since. The Romans had made the natural blunder of greed in taking all gold and silver mines into the hands of the State,[222] where speculative private enterprise would have gone on working them at a loss, and so adding—vainly enough—to the total bullion in circulation, on which the State could levy its taxes. Even as it was, when they were losing nothing, but rather checking loss, by abandoning the mines, a falling-off in revenue from one source could have been made good by taxation if the fiscal system had remained unimpaired, and if the former income of Italy had not been affected by other causes than a stoppage of mining output.
If the mere cessation of public gold-mining were the cause of a general weakening of the imperial power, and by consequence the cause of the collapse in Italy, it ought equally to have affected the Eastern Empire, which we know to have possessed a normal sufficiency of bullion all through the Dark and Middle Ages, though it had no mines left.[223] The fact is that, when Valentinian and Valens divided the Empire between them, the former chose the western half because he shared the delusion that the Spanish mines were a greater source of real wealth than the fruitful provinces of the east. Those could always procure the bullion they required, because they had produce to exchange for it. Gold mines even of average fertility could have availed no more; and if Italy had remained agriculturally productive she could have sustained herself without any mines.
Dr. Cunningham, in his study of the economic conditions of the declining Empire, appears to lay undue stress on the factor of scarcity of bullion, and does not duly recognise the difference of progression between the case of Italy and that of the east. "The Roman Empire," he writes (p. 187, note), lacked both treasure and capital, "and it perished." When? The eastern seat of the Empire survived the western by a thousand years. "It seems highly improbable," he argues again (p. 185), "that the drain of silver to the east, which continued during the Middle Ages, was suspended at any period of the history of the Empire." But such a drain (which means a depletion) cannot go on for twelve hundred years; and it was certainly not a drain of silver to the east that ruined the Byzantine Empire. Finlay's dictum (i, 52) that the debasement of the currency between Caracalla and Gallienus "annihilated a great part of the trading capital in the Roman Empire and rendered it impossible to carry on commercial transactions, not only with foreign countries but even with distant provinces," is another erroneous theorem.
It seems clear that the Italian collapse occurred as it did because, after the fall of the three great possessions, Gaul, Spain, and Africa, there was left only the central State, made impotent by long parasitism to meet the growing barbarian pressure. Italy in the transition period can have yielded very little revenue, though Rome had for the barbarians plenty of hoarded plunder; and the country had long ceased to yield good troops. Gaul itself had been monstrously taxed; and it must have been no less a prudent than a benevolent motive that led Julian to reduce to £2,000,000 the revenue of £7,000,000 extorted by Constantine and Constantius.[224] The greater the depression in the sources of income, and the greater the costs of the frontier wars, the harder became the pressure of the fiscal system, till the burdens laid on the upper citizens who formed the curia[225] put them out of all heart for patriotic action, and drove many to flight, to slavery, or the cloister. Towards the end, indeed, there was set up a rapid process of economic change which substituted for slaves a class of serfs, coloni, adscriptitii, and so on, who though tied to the land paid a rent for it and could keep any surplus; but under this system agriculture was thus far no more a source of revenue than before. Latterly the very wine of Italy grew worthless, and its olives decayed;[226] so that in once fruitful Campania, "the orchard of the south," Honorius in the year 395 had to strike from the fiscal registers, as worthless, more than three hundred thousand acres of land[227]—an eighth of the whole province. After the ruinous invasions of Rhadagast and Alaric, fresh remissions of taxation had to be given, so that as the danger neared the defence weakened.[228] In the east, again, there was no impulse to succour the falling west; and indeed there was not the ability. The fiscal power of the Emperor was inelastic; his revenues, extorted by cruel pressure, needed careful husbanding; his own world needed all his attention; and the eastern upper class of clerics and officials were not the people to strain themselves for the mere military retention of Britain or Gaul or Italy, as Rome would have done in the republican period, or as the emperors would have done before the period of decentralisation. For the rich agricultural provinces of Africa they did strive with success when Belisarius overthrew the Vandals; and in that age, when Italy had once more become revenue-yielding through the revival of her agriculture, it was worth the while of the east to reconquer Italy also; but the old spirit of resolute dominion and aggression was gone. Armies could still be enrolled and generalled if there was pay for them; but the pay failed, not because bullion was lacking, but because the will and power to supply and apply it in the old fashion was lacking. The new age, after Theodosius, looked at these matters in a different light—the light of commercial self-interest and Christian or eastern disregard for Roman tradition and prestige. The new religion, Christianity, was a direct solvent of imperial patriotism in the old sense, transferring as it did the concern of serious men from this world to the next, and from political theory to theological. In Italy, besides, the priesthood could count on making rather more docile Christians of the invaders than it had done of the previous inhabitants; so that Christian Rome, once overrun, must needs remain so.
[Finlay (ed. cited i, 294) suggests that "probably the knowledge which the Emperor Justin and his cabinet must have possessed of the impossibility of deriving any revenue from the agricultural districts of Italy offers the simplest explanation of the indifference manifested at Constantinople to the Lombard invasion." But he had already noted (p. 236, note) that a great revival of agriculture took place in the reign of Theodoric. Then it could only be through the exhaustion of the subsequent wars that Italy was incapable of yielding a revenue. The true explanation of Justin's inaction is probably not indifference but impotence, the Empire's resources being then drained.
After the invasion of the Lombards the clergy and Senate of Rome had to send a large sum in bullion to induce the Emperor Maurice to listen to their prayers for help. Still the help could not be given, though, save in the case of the coast towns (see below, p. 188), tribute was paid to Byzantium till the final breach between Rome and Leo the Iconoclast. (Gibbon, Bohn ed. v, 114.)
Guizot (Histoire de la Civilisation en France, 13e éd. i, 75, 76) notes the fundamental difference in the attitude of the Church under the old and eastern emperors and under the Teutonic rule. Symonds (Renaissance in Italy, 2nd ed. i, 43) thinks this was a result of Theodoric's not having made Rome his headquarters, and his having treated it with special respect. But the clergy of Gaul at once gained an ascendency over the Frankish kings, and the popes would probably have done as well with resident emperors as with absentees. Their great resource was that of playing one Christian monarch against another—a plan not open to the patriarch of Constantinople.]
That the Empire could still at a push raise armies and find for them generals who could beat back the barbarians was sufficiently shown in the careers of Stilicho and Aetius and Belisarius; but the extreme parsimony with which Justinian supported his great commander in Italy is some proof of the economic difficulty of keeping up, even in a period of prudent administration,[229] a paid force along the vast frontiers of what had been Hadrian's realm. Only as ruled by one central system, inspired by an ideal of European empire, and using the finance and force of the whole for the defence of any part, could that realm have been preserved; and when Diocletian, while holding mechanically by the ideal of empire, began the disintegration of its executive, he began the ending of the ideal. The creation of an eastern capital was now inevitable; and when once the halving of the Empire had become a matter of course, the west, hollow at the core, was fated to fall. We should thus not be finally wrong in saying that "the Roman idea" died out before the Western Empire could fall; provided only that we recognise the economic and other sociological causation of the process.