The progress in language has not been by multiplication, which would be but a progress in degradation under the now well-recognized laws of evolution; but it has been in integration from a vast multiplicity toward a unity. True, all evolution has not been in this direction. There has often been degradation as exhibited in the multiplicity of languages and dialects of the same stock, but evolution has in the aggregate been integration by progress towards unity of speech, and differentiation (which, must always be distinguished from multiplication) by specialization of the grammatic process and the development of the parts of speech.
When a people once homogeneous are separated geographically in such a manner that thorough inter-communication is no longer preserved, all of the agencies by which languages change act separately in the distinct communities and produce different changes therein, and dialects are established. If the separation continues, such dialects become distinct languages in the sense that the people of one community are unable to understand the people of another. But such a development of languages is not differentiation in the sense in which this term is here used, and often used in biology, but is analogous to multiplication as understood in biology. The differentiation of an organ is its development for a special purpose, i. e., the organic, specialization is concomitant with functional specialization. When paws are differentiated into hands and feet, with the differentiation of the organs, there is a concomitant differentiation in the functions.
When one language becomes two, the same function is performed by each, and is marked by the fundamental characteristic of multiplication, i. e., degradation; for the people originally able to communicate with each other can no longer thus communicate; so that two languages do not serve as valuable a purpose as one. And, further, neither of the two languages has made the progress one would have made, for one would have been developed sufficiently to serve all the purposes of the united peoples in the larger area inhabited by them, and, cœteris paribus, the language spoken by many people scattered over a large area must be superior to one spoken by a few people inhabiting a small area.
It would have been strange, indeed, had the primitive assumption in philology been true, and the history of language exhibited universal degradation.
In the remarks on the "Origin of Man," the statement was made that mankind was distributed throughout the habitable earth, in some geological period anterior to the present and anterior to the development of other than the rudest arts. Here, again, we reach the conclusion that man was distributed throughout the earth anterior to the development of organized speech.
In the presence of these two great facts, the difficulty of tracing genetic relationship among human races through arts, customs, institutions, and traditions will appear, for all of these must have been developed after the dispersion of mankind. Analogies and homologies in these phenomena must be accounted for in some other way. Somatology proves the unity of the human species; that is, the evidence upon which this conclusion is reached is morphologic; but in arts, customs, institutions, and traditions abundant corroborative evidence is found. The individuals of the one species, though inhabiting diverse climes, speaking diverse languages, and organized into diverse communities, have progressed in a broad way by the same stages, have had the same arts, customs, institutions, and traditions in the same order, limited only by the degree of progress to which the several tribes have attained, and modified only to a limited extent by variations in environment.
If any ethnic classification of mankind is to be established more fundamental than that based upon language, it must be upon physical characteristics, and such must have been acquired by profound differentiation anterior to the development of languages, arts, customs, institutions, and traditions. The classifications hitherto made on this basis are unsatisfactory, and no one now receives wide acceptance. Perhaps further research will clear up doubtful matters and give an acceptable grouping; or it may be that such research will result only in exhibiting the futility of the effort.
The history of man, from the lowest tribal condition to the highest national organization, has been a history of constant and multifarious admixture of strains of blood; of admixture, absorption, and destruction of languages with general progress toward unity; of the diffusion of arts by various processes of acculturation; and of admixture and reciprocal diffusion of customs, institutions, and traditions. Arts, customs, institutions, and traditions extend beyond the boundaries of languages and serve to obscure them, and the admixture of strains of blood has obscured primitive ethnic divisions, if such existed.
If the physical classification fails, the most fundamental grouping left is that based on language; but for the reasons already mentioned and others of like character, the classification of languages is not, to the full extent, a classification of peoples.
It may be that the unity of the human race is a fact so profound that all attempts at a fundamental classification to be used in all the departments of anthropology will fail, and that there will remain multifarious groupings for the multifarious purposes of the science; or, otherwise expressed, that languages, arts, customs, institutions, and traditions may be classified, and that the human family will be considered as one race.