No sharp line can be drawn between progressive and non-progressive societies. The most non-progressive society has made a considerable progress upward from the brute. In the most progressive societies there are many elements of conservatism which prevent a rapid and unchecked advance. Here again, however, it is convenient to distinguish between the extremes while recognizing the fact that they shade off, one into the other. In progressive societies there is a constant struggle between the desire for certainty in law and the desire for doing justice and for adapting the law to the new and constantly changing conditions. The life of a progressive society is constantly propounding new problems to its law and the law is constantly modifying itself so as to give some kind of satisfactory answer to these new problems. In a non-progressive society the desire for certainty is easily the victor. This is largely due to the fact that in a non-progressive society there are few new ideas to arise outside of the law and to influence it; and accordingly, since few new problems are presented to the law, there is little need for the law to develop. If, however, the society in which rules of law have become established is a progressive one, there will sooner or later be a conflict between the needs of the advancing community and the archaic forms of law which have ceased to represent the thought and feeling of the average mass of the community. If a revolution is to be averted there must be some adjustment of law to the facts of life. What happens then depends on the relative force of the contending ideas. On the one hand the forces of repression and conservatism may be strong enough to check all progress until the pressure of advance reaches the breaking point. Then there is a cataclysm of some sort, great or small; a revolution, whether attended with bloodshed or not, since advance is made not by developing the pre-existing law, but by breaking with it. On the other hand the forces that make for progress may at the outset be stronger or better organized: and those that make for conservatism and repression may have better political instinct. In such cases the pre-existing law may be developed by a gradual piece-meal improvement, never losing touch with advance completely and never completely breaking with the old. In such a community law will often be uncertain, but revolutions will be few and far between. It has been the strength of the English-speaking peoples that they have generally chosen the second of these methods of developing their law and their institutions. This has been accomplished in English law by a partial reception of other systems of law to meet the needs of advancing society as well as an internal development of its own principles. Anglo-Saxon law had been compelled to submit to a partial reception of feudal law before the establishment of the king's courts under Henry II; and the task at once devolved on the king's courts to work some kind of order out of the mass of Anglo-Saxon custom, feudal law and Anglo-Norman administration. The partial reception of ecclesiastical law and of the law-merchant,1 together with the limited influence of Roman law directly on the king's courts, or indirectly through equity, all aided in the task of adapting the English law to the needs of a progressive society. The result is that while on the one hand the Anglo-Saxon law has superficially little in common with the law of the king's courts from the latter part of the twelfth century to the fifteenth century, and while this law in turn has superficially little in common with the Anglo-American law of to-day, there is no one point of time at which we can say that the law broke absolutely with the past and took a new start, with new principles, unaided and undisturbed by the earlier systems of law. The nearest approach to this which any historians of the law see is in the rapid development of law by the king's courts in the twelfth and thirteenth centuries. It is possible that a future historian will see a similar period of rapid growth in the latter part of the nineteenth and the early part of the twentieth centuries. The uncertainty of the law occasionally thus produced is a mark of the strength and rapid growth of the people; not of the inferiority of the law. If our civilization ever becomes stationary, it will not be long before our law will become at least as fixed and certain as was Justinian's law; and as dead.

1See ch. XIV.

1Mogadora v. Holt, 1 Shower, 318; Hodges v. Stewart, 12 Mod. 37.

For a discussion of the reception of the law merchant by the common-law courts, see Early History of the Law Merchant in England, by A. T. Carter, 17 Law Quarterly Review, 232.

For an account of the reception of the law merchant, see The Origins and Early History of Negotiable Instruments, by W. S. Holdsworth, 31 Law Quarterly Review, 12, 173 and 370, and 32 Law Quarterly Review, 20 (especially the last article).