– were left substantially intact by this authoritarian evolution of public law, which by and large did not trespass upon the inter-citizen domain. The possessing classes continued to be juridically guaranteed in their property by the precepts established in the Republic. Beneath them, criminal law – essentially designed for the lower classes – remained as arbitrary and repressive as it had always been: a social safeguard for the whole ruling order. The Principate thus preserved the classical legal system of Rome, while superimposing on it the new innovatory powers of the Emperor in the realm of public law. Ulpian was later to formulate the distinction which articulated the whole juridical corpus under the Empire with characteristic clarity: private law – quod ad singulorum utilitatem pertinet – was in particular separate from public law – quod ad statum rei Romanae spectat. The former suffered no real eclipse from the extension of the latter.28 It was, indeed, the Empire which produced the great systematizations of civil jurisprudence in the 3rd century, in the work of the Severan prefects Papinian, Ulpian and Paulus, that transmitted Roman law as a codified body to later ages. The solidity and stability of the Roman imperial State, so different from anything the Hellenistic world produced, was rooted in this heritage.
The subsequent history of the Principate was largely that of the increasing ‘provincialization’ of central power within the Empire. Once the monopoly of central political office enjoyed by the Roman aristocracy proper had been broken, a gradual process of diffusion integrated a wider and wider ambit of the Western landed classes outside Italy itself into the imperial system.29 The origin of the successive dynasties of the Principate was a straightforward record of this evolution. The Roman patrician Julio-Claudian house (Augustus to Nero) was followed by the Italian municipal Flavian line (Vespasian to Domitian); succession then passed a series of Emperors with a provincial Spanish or Southern Gallic background (Trajan to Marcus Aurelius). Spain and Gallia Narbonensis were the oldest Roman conquests in the West, whose social structure was consequently closest to that of Italy itself. The composition of the Senate reflected much the same pattern, with a growing intake of rural dignitaries from Transpadane Italy, Southern Gaul and Mediterranean Spain. The imperial unification of which Alexander had once dreamed appeared symbolically accomplished by the epoch of Hadrian, the first Emperor to tour his whole immense domain from end to end in person. It was formally consummated by Caracalla’s decree of A.D. 212 granting Roman citizenship to nearly all free inhabitants throughout the Empire. Political and administrative unification was matched by external security and economic prosperity. The Dacian kingdom was conquered and its gold mines annexed; the Asian frontiers were extended and consolidated. Agricultural and artisanal techniques slightly improved: screw presses promoted oil production, kneading-machines facilitated the manufacture of bread, glass-blowing became widespread.30 Above all, the new pax romana was accompanied by a buoyant surge of municipal rivalry and urban embellishments in virtually all the provinces of the Empire, exploiting the architectural discovery by Rome of the arch and the vault. The Antonine epoch was perhaps the peak period for city construction in Antiquity. Economic growth was accompanied by the flowering of Latin culture in the Principate, when poetry, history and philosophy blossomed after the relative intellectual and aesthetic austerity of the early Republic. To the Enlightenment this was a Golden Age, in Gibbon’s words ‘the period in the history of the world during which the condition of the human race was most happy and prosperous’.31
For some two centuries, the tranquil magnificence of the urban civilization of the Roman Empire concealed the underlying limits and strains of the productive basis on which it rested. For, unlike the feudal economy which succeeded it, the slave mode of production of Antiquity possessed no natural, internal mechanism of self-reproduction, because its labour-force could never be homeostatically stabilized within the system. Traditionally, the supply of slaves largely depended on foreign conquests, since prisoners of war probably always provided the main source of servile labour in Antiquity. The Republic had sacked the whole Mediterranean for its manpower, to install the Roman imperial system. The Principate halted further expansion, in the three available remaining sectors of possible advance, Germany, Dacia and Mesopotamia. With the final closure of the imperial frontiers after Trajan, the well of war captives inevitably dried up. The commercial slave-trade could not make up for the shortages that resulted, since it had always itself been largely parasitic on military operations for its stocks. The barbarian periphery along the Empire continued to provide slaves, bought by dealers at the frontiers, but not in sufficient numbers to solve the supply problem in conditions of peace. The result was that prices started to climb sharply upwards; by the 1st and 2nd centuries A.D., they were 8 to 10 times the levels of the 2nd and 1st centuries B.C.32 This steep rise in costs increasingly exposed the contradictions and risks of slave labour for its proprietors. For each adult slave represented a perishable capital investment for the slave-owner, which had to be written off in toto at death, so that the renewal of forced labour (unlike wage-labour) demanded a heavy preliminary outlay in what had become an increasingly tight market. For, as Marx pointed out, ‘the capital paid for the purchase of a slave does not belong to the capital by means of which profit, surplus-labour, is extracted from him. On the contrary, it is capital which the slave-owner has parted with, it is a deduction from the capital which he has available for actual production.’33 In addition, of course, the maintenance of slave offspring was an unproductive financial charge on the owner, which inevitably tended to be minimized or neglected. Agricultural slaves were housed in barrack-like ergastula, in conditions approximating to those of rural prisons. Female slaves were few, being generally unprofitable to owners because there was a lack of ready employment for them, beyond domestic tasks.34 Hence the sexual composition of the rural slave-population was always drastically lopsided, and was compounded by the virtual absence of conjugality within it. The result must have been a customarily low rate of reproduction, which would have diminished the size of the labour-force from generation to generation.35 To counteract this fall, slave-breeding seems to have been increasingly practised by landowners in the later Principate, who granted premia to women-slaves for child-bearing.36 Although there is little evidence as to the scale of slave-breeding in the Empire, it may have been this resort which for a time mitigated the crisis in the whole mode of production after the closure of the frontiers: but it could not provide a long-term solution to it. Nor, meanwhile, was the rural free population increasing, to compensate for losses in the slave sector. Imperial anxieties about the demographic situation in the countryside were revealed as early as Trajan, who instituted public loans to landowners for the upkeep of local orphans, an omen of shortages to come.
Nor could the dwindling volume of labour be compensated by increases in its productivity. Slave agriculture in the late Republic and early Empire was more rational and profitable to landowners than any other form of exploitation of the soil, partly because slaves could be utilized full-time, where tenants were unproductive for considerable stretches of the year.37 Cato and Columella carefully enumerate all the different indoor and out of season tasks to which they could be set when there were no fields to be tilled or crops to be gathered. Slave artisans were just as proficient as free craftsmen, since they tended to determine the general level of skills in any trade by their employment in it. On the other hand, not only did the efficiency of the latifundia depend on the quality of their vilicus bailiffs (always the weak link in the fundus), but supervision of slave-labourers was notoriously difficult in the more extensive cereal crops.38 Above all, however, certain inherent limits of slave productivity could never be overcome. The slave mode of production was by no means devoid of technical progress; as we have seen, its extensive ascent in the West was marked by some significant agricultural innovations, in particular the introduction of the rotary mill and the screw press. But its dynamic was a very restricted one, since it rested essentially on the annexation of labour rather than the exploitation of land or the accumulation of capital; thus unlike either the feudal or capitalist modes of production which were to succeed it, the slave mode of production possessed very little objective impetus for technological advance, since its labour-additive type of growth constituted a structural field ultimately resistant to technical innovations, although not initially exclusive of them. Thus, while it is not wholly accurate to say that Alexandrine technology remained the unchanging basis of work-processes in the Roman Empire, or that no labour-saving devices of any kind were ever introduced in the four centuries of its existence, the boundaries of the
