The reasons for and the nature of the strict rules introduced by Diocletian are summarized by Mosca: ³³

Beginning with Diocletian's time, in order to deal with the grave depression that had fallen upon the empire . . . the state assumed extraordinary powers and exercised extraordinary functions of control. It presumed to discipline the whole economic sphere of life, fixing wages and the prices of crops. In order to assure continuity in what we now call "public services," it prohibited those who were employed in them from leaving their positions and obliged the son to follow the trade his father had followed.

These regulations were introduced only after every effort had been made to keep the Empire solvent by the ordinary means of taxation. The middle classes formerly had been burdened with the costs of municipal upkeep and had been crushed under the load. Some senators had fled the very towns their grandfathers had helped to build and had secluded themselves on large agricultural estates. Now the workers on the land became coloni, and those in the shops were likewise held in positions of dependence. ³⁴ Now business began to return to normal. The social conditions in agriculture improved in that slavery gave way to serfdom; in the cities, except the capital, the workers were provided with more regular work and an end was made of the dole.

About the development of the classes in the Roman world writers have diverse opinions, but from what is well known, the following citation can hardly be called a correct summary of the meaning of these changes: ³⁵

Under the Republic, the individual's position and activities had been largely determined by his own will and efforts. The Empire reduced the population to a number of castes and classes.

Although, as Bede Jarrett and many others have shown, the Western Empire thrived and prospered and kept civilization going. It had nevertheless been referred to as an "intolerable system of caste and servitude." ³⁶ From the point of view of modern ideals the Byzantine Empire seems truly "intolerable," but when compared to the hundred years preceding the adoption of the regulations, the new order of the eastern Mediterranean was a godsend. Civilization made a choice between a kind of bankrupt liberty and security. The choice made proved to be a worthy one. One reads much of artisans at work, ³⁷ little of the urban rubble and municipal feasts for the poor. The middle classes were no longer being wiped out; business men were not fleeing from the honors of their fathers to hide among the proletariat in order to escape imperial responsibilities, as had been so tragic and so common at an earlier period and still took place in the West. ³⁸ There were now numerous bourgeois who "served to maintain a kind of social equilibrium." ³⁹

Social class trends in the West. The development of class lines in the West did not follow the same pattern as in the East. In Italy, as early as the time of Pertinax, many estates lay deserted. ⁴⁰ In some sections Germans were invited to settle in great colonies in order to fill up the gap left by migration and death. ⁴¹ Both of these facts tended to establish serfdom and ease the rigors of slavery.

Four categories of persons came to be serfs: (1) slaves; (2) inquilini, who were either captives or migrant barbarians; (3) coloni, who were originally small lease-holders; and (4) independent peasants, of whom there were still a few. ⁴²

Since the towns were long the bases of the administrative machinery of the Roman Empire, the burden of collecting taxes fell upon them. But in the West the towns were declining in every respect. Senatorial families had been quick to leave them to their fate and to withdraw to the country. ⁴³ These enjoyed many privileges and exemptions, among which "the most important was that which relieved senators from municipal burdens." ⁴⁴