It is useless to say that there were illusions at the bottom of these tendencies. We all know to what this universal liberation of men was to lead. But what is most important here is the fact that these persuasions arose from a conception of law, which considered it as detached from the social causes which produced it. Likewise that reason, to which these ideologies appealed, reduced itself to relieving labor, association, traffic, commerce, political forms and conscience from all limits and all obstacles which prevented free competition. I have already shown in another chapter how the great Revolution of the eighteenth century may serve us for experience. And if there is still some one to-day who insists on speaking of a rational law which dominates history, of a law, in short, which would be a _factor_, instead of being a simple _fact_ in historic revolution, that means that he is living out of our time and that he has not understood that our liberal and equalitarian codification has already, in fact, marked the end and the term of that whole school of natural law. By different ways we have arrived in this century at reducing law, considered previously as a rational thing, into a material thing, and thus into a thing corresponding to definite social conditions. In the first place, the interest in history gained in extent and in depth, and it led students to recognize that to understand the origins of law, it was not sufficient to stop at the data of pure reason, nor at the study of Roman law alone. Barbaric laws, the usages and customs of nations and societies, so despised by the rationalists, have been theoretically restored to honor. That was the only way to arrive, through the study of the most ancient forms, at an understanding of how the most recent forms could have been successively produced. Codified Roman law is a very modern form; that personality, which it assumes as a universal subject, is an elaboration of a very advanced epoch, in which the cosmopolitanism of social relations was dominated by a military-bureaucratic constitution. In this environment, in which a written code of reason had been built up, there was no longer any trace of spontaneity or popular life, there was no more democracy. This same law, before arriving at this crystallization, had arisen and had developed: and if we study it in its origins and in its developments, and especially if, in this study, we employ the comparative method, we recognize that, upon many points, it is analogous to the institutions of inferior societies and nations. It therefore becomes evident that the true science of law can be nothing less than the genetic history of the law itself.