784 THE AMERICAN JOURNAL OF SOCIOLOGY
a matter of observation, whereas progress is a matter of judgment involving the application of a subjective standard, those who desire to see sociology a true science are justified in insisting that social dynamics deal with the factors and manner, not of social progress merely, but of social change.
In the arts we ask if the new thing is more useful than the old ; in the sciences we ask if the new proposition brings us nearer the truth. But there are other important changes for which there is no sure test. In Rome during most of the imperial period that progress which flows from the advance of technique and knowledge was almost unknown. Says Seeck :
From Augustus to Diocletian the equipment of the legionary remained the same. No improvement of tactics, no new means of warfare, was
developed in the course of three centuries Neither in agriculture nor
in technique nor in administration does a single new idea of any significance come to light after the first century. Literature and art, too, are confined
to a sterile imitation which becomes ever more empty and feeble
The Neo-Platonic philosophy and the development of Christian dogma are the only achievements which relieve this era from complete futility.
Yet these barren ages are full of social changes which are richly instructive as to the forces that lurk in the bosom of society. Why, after the gulf between Romans and provincials had been filled in, did a chasm open between honestiores and humiliores? Why did slaves give place to coloni and adscripti glebae? Why did the law fetter the worker to his father's occupation? Why did taxes come to be paid in kind? Why did the petty landowner voluntarily yield up his holding to some powerful proprietor in order to receive it back on a feudal tenure ? Why did gladiatorial shows cease ? What influence lifted the "overseer" of the early Christian community to the lofty chair of the episcopus or bishop ? What was it that elevated the bishop of Rome to the papal throne ? How can the rise of the monastic movement be explained ? Surely the forces here at work should figure in a theory of social dynamics !
When a mammal thrust northward gets a heavier coat of hair, or a bird acquires the nest-building instinct with the advent of a rodent that destroys her eggs and young on the ground, we have a case of adaptation. Now, this way of inter-
