It is true that philology, applied to anthropological research, is of immense assistance to it; it can give us powerful inductions on the history of the past, and on the origin of the present human species. But even these, solutions agree very well with the theory of gradual evolution, and with the corollary of this theory, namely, that man has not always possessed the faculty of speech.[345] Philologists tell us, for instance, that two sister tribes may have been able, at some past time, to create on each side of a mountain two different idioms, which may produce in their turn two families of languages absolutely irreducible one from the other. This is what would take place, according to M. Renan, when the sons of the same parents, separating on the sides of the Imäus, became the double branch from whence have sprung the Semites on one side, and the Aryas on the other. This would be the explanation of the fact so embarrassing for anthropologists, that physical characteristics are sensibly identical among the Semites and Europeans, whilst these races are as distinct as possible in the matter of language. Now, we may even go further, and infer from these facts that the common species from whence the Semites, on the one hand, and the Aryas, on the other, are descended, did not yet know how to speak. Inversely to Latham, some anthropologists have given, in our opinion, too little importance to language: we speak especially of Edwards and M. Omalius d’Halloy.[346] The truth lies, doubtless, between these two extremes. It must be acknowledged that language can very often furnish excellent evidence, but it must not be forgotten that it shows at the same time a more rapid liability to change than moral characteristics and corporal form. Niebuhr seems to us to be right when he insists upon the precautions to be taken in order to apply philology in a useful manner to the determination of races, and he concludes that we must give the greatest attention to physical configuration.[347] This is also the opinion of Humboldt[348] and M. Vivien.[349] A language, like every custom, and every act of individual relation, can transmit itself from one race to another which is very different. The unity of a family of languages is not always sufficient to establish that the people who speak these idioms are of one and the same origin; we can only conclude from it that they have been in relation one with the other, and it is even reasonable to admit that this cause has been able to act with a decisive influence at the epoch when man first commenced to lisp.[350] These two tribes meeting for the first time, physically strangers one to the other, were doubtless able to borrow mutually certain habits, and to mingle in a decided manner their two manners of explaining their thoughts, from which has resulted one sole language, in which we cannot distinguish except by analysis the two different branches which have contributed to its formation.