The crisis in civilization, which developed rapidly after the reign of Aurelius, led directly to the strict social class rules of Diocletian and his successors; a discussion of it is therefore relevant. This crisis was in no small degree caused by the collapse of the economic base upon which the mushroom cities were built.

The order of sequence of pertinent events was: (1) conquest, booty, slaves; (2) peace and prosperity, decline in population, construction of miniature Romes throughout Italy, North Africa, and Asia Minor; (3) economic collapse, after economy, decentralization of economic life in the West which set in with Septimus Severus, burdensome taxes, strict legal class categories, hereditary social class divisions.

Especially during the reign of Hadrian were cities constructed which attempted to equal "the rank and splendor" of their great parent. ²⁶ Cities vied with each other to become the more splendid, and communities and provinces which were by no means rich fell into the spirit of the age and also overbuilt. The proconsul had "sometimes to moderate their emulation." ²⁷ Rich men and aristocratic alike deemed it almost an obligation to contribute what amounted to monuments to their names. Atticus built monumental buildings in his age of splendor equivalent to those constructed by the Rockefellers in this century.

But the funds for maintenance did not suffice. Instead of increasing productivity, many of the cities atracted economic effort from agriculture into sterile channels of pure consumption. Summarized, the story reads: ²⁸

It was an age of engineers and architects, who turned villages into cities and built cities in the desert, adorned the temples and stately arches and basilicas, and feeding their fountains from the springs of distant hills. The rich were powerful and popular; and never had they to pay so heavily for popularity and power. The cost of civic feasts and games, of forums and temples and theatres, was won by flattery, or extorted by an inexorable force of public opinion from their coffers. The poor were feasted and amused by their social superiors who received a deference and adulation expressed on hundreds of inscriptions. And it must be confessed that these records of ambitious munificence and expectant gratitude do not raise our conception of either the economic or moral condition of the age.

Like a university that has allowed itself to be given more buildings than it can heat and sweep and staff with teachers, the Roman provinces began to feel the pinch of shortages. Funds were not sufficient to keep the new system of feasts and easy consumption "a going concern." The bubble burst. Within a short century after Aurelius took office the disintegration of Roman civilization in the West had gone far beyond repair: starvation, pestilence, war, "had consumed, in a few years, the moiety of the human species." ²⁹ There was a severe shortage of coins, roadways were deserted, cities fell into a hunger slump. The luxury of magnificent cities was "false consumption." Knight states: ³⁰

Many of the showy public works, such as amphitheaters, baths, and palaces, which appeared in imperial times, were constructed primarily to keep otherwise idle labor employed. Like the Egyptian pyramids, they were natural products of the contemporary social order.

Retrenchment and stabilization in the East. From the reign of Marcus Aurelius, when the weakness of the Empire became clear for the first time, to the reign of Diocletian, about one hundred years later, civilization experienced one of its swiftest declines. Upon the different strata of the population the era from about 170 AD. onward had different effects.

The gilds, called collegia, which for centuries had either been forbidden or allowed to continue only as friendly societies, became official, strong, and effective instruments of social policy. Special privileges and duties were associated with artisan and trading groups. Each gild had a regulated monopoly, each its assembly, its leader, its brotherhood. ³¹ The bureaucrats "held together the Byzantine Empire; it was enlightened, industrious and orderly." ³²