The language as an ethnographical element of the ethnographical complex has the greatest importance in the process of the establishment of the ethnical and the interethnical equilibrium. We have seen that the centripetal and centrifugal movements and their equilibrium in the ethnos define either the process of consolidation of the unit or its further disintegration into smaller ones. The mechanism of this process is rather complex, so it requires some additional remarks.
Let us take the instance of a well-adapted ethnos which multiplies very rapidly. It may spread over the territory if the latter is free; but it meets with opposition, if the territory is occupied. Under the pressure of ethnoses, the ethnos pressed may react in different manners. It may oppose the aggression of the neighbour by force, or it may come to a certain agreement which facilitates the existence of its numerous neighbours. So, for instance, it may come into close contact with other ethnoses through the establishment of economic co-operation, or to accept certain functions in a larger economic unit. Such is the case, for instance, when agricultural groups are co-operating with groups living on specialized industries. In certain geographical regions several ethnoses may be involved into such a co-operative system in which the interest of the survival of the ethnoses will be better assured than in an isolated existence. However, this situation bears elements of disappearance of ethnoses, for this is practically the first step for the extension of the former limits of one of the ethnoses involved. In fact, owing to the regular relations, a close contact is soon established and a great impediment for the relations — the language — becomes familiar to the co-operating ethnoses. Then a gradual substitution of one language by another may take place. When the language does not obstruct the influx of other ethnographical elements transmitted through the language, the ethnographical complexes blend together, or some better adapted elements of one complex substitute the elements of another complex. When the difference in language and ethnographical complex does not obstruct the approach of sexes, the process blending the two ethnoses is completed by the establishment of unregulated intermarriage between formerly distinct ethnoses. In this way the limits of biological process, and cultural, as well as linguistical, adaptation are extended, and a large, new ethnos is formed by the process of complete fusion. Naturally, the ethnos, physically better adapted to the given conditions, and being more numerous than the others, may gradually substitute its former rivals. This is one of the most common cases. The process of fusion of ethnoses and the loss of cultural independence is the most frequent occurrence. So the change of language is so frequent a phenomenon that, for instance, A. Meillet, referring to the languages of the Mediterranean circle, says: «Il n'y a presque pas un peuple qui n'ait change de langue au moins une fois, et generallement plus d'une fois» («La Methode,» op. cit., p. 72). Yet the same opinion is shared by most of the linguists who have been interested in the problem. It is quite natural, for the migrations of ethnoses are going on during the whole known history of mankind, and the change of cultural complexes [44] is also a fact which is closely correlated with the change of language, for the spread of large, powerful ethnoses and their new form of adaptation — «civilization» — involves neighbouring ethnoses.
From the analysis of correlation between language and anthropological types, we know that these aspects of ethnoses cannot be connected at all. Yet we also know that the change of the cultural complex may occur without any essential change of language except the increase of vocabulary. So if, in ethnoses, there are occurrences of coexistence of the same anthropological types, cultural phenomena, and languages, they are not indicative of a casual correlation between these phenomena. Such coincidences may be used as good historic evidences, but one cannot infer the common origin of populations from the fact of identic culture, and particularly language, and one cannot postulate the existence of a similar language and culture in general in the past amongst the ethnoses which at present are more or less alike from the physical point of view.
We have already seen that the change of language sometimes occurs partially, as it is with other cultural complexes, and the process of mixing and substitution of different anthropological types is also a common phenomenon. So the formation of ethnoses. also their agglomeration and disintegration, is such that the preservation of language, and generally the cultural complex, and an intact population in one and the same continuing ethnos may have only a theoretical interest, for such occurrences are practically unknown. From three different quarters — linguistical, ethnographical, and anthropological — we have the same ideas; namely, unreliability of all these evidences taken alone for showing the origin and the history of ethnoses [45]. It is now evident that it cannot be otherwise, for culture and particularly language are functions and ethnos is a process, also one of the functional phenomena, so that the actual relations which exist between these functions may not be discovered before we know the material substrata of all these functions, if such differentiated substrata exist. At the present time, we know practically very little about it and probably for this reason the functions are usually considered as evolving matter. Indeed, the ethnoses are concrete units — ethnical units — in so far as they are built up of populations, but as a unit they are functions, while the cultural elements have not even this appearance.
44. The connexion between the language and the cultural complex in general for some authors is so evident that they postulate it as a leading idea for further researches. A. Meillet («La Methode,» op. cit., p. 20) formulates it in reference to the common languages as follows: «Chacune des grandes 'langues communes' du passe doit exprimer un type de civilisation»; and, furthermore, «ce sera l'une des taches de l'etude de l'homme dans l'avenir que de relier les langues communes aux aires de civilisation'' (id., p. 21) — an attempt which has already been made.
45. Still in a lesser degree, they are reliable for the problem of «nations,» etc.