This process, resulting finally in the practical elimination of customary law and the turning of lawyers' law into statutes, has given to the external form of modern law a rigid immobility which apparently renders impossible all development except by means of legislation. That form corresponds very well to the spirit of the prevailing scientific doctrine, and sometimes it is actually advocated in so many words as the true principle. Yet, notwithstanding all this, that formal rigidity has always been much more apparent than real. The reason for this is by no means lack of intention to make it real, but rather the existence of certain truths which, like all truths, cannot be kept from asserting themselves.
No theory of the application of law can get around the difficulty that every body of formulated rules is in its very nature incomplete; that it is really antiquated the very moment it has been formulated. Consequently, it can hardly govern the present and never the future. No such theory will ever be able to prevent the perpetual course of evolution of the social institutions to which the law is applied, whereby the formulated rules of decision are constantly obliged to deal with new subject-matters. And it will also never be possible to avoid the fact that the individuals intrusted with the application of the law, being children of their nation and their age, will apply the law in the spirit of their nation and their age, and not in the spirit of past centuries, according to the "intention of the legislator." The most solid theories and the most powerful legislation must alike be shattered upon the rock of such realities.