Here, then, is the first distinction to make: the social groups that we are to describe in this work under the names of clans, tribes, nations, populations, and peoples, according to their numerical importance and the degree of complication of their social life, are formed for us by the union of individuals belonging usually to two, three, or a greater number of “somatological units.” These units are “theoretic types” formed of an aggregation of physical characters combined in a certain way. The separate existence of these units may be established by a minute analysis of the physical characters of a great number of individuals taken haphazard in any given “ethnic group.” Here are, then, entities, theoretic conceptions exactly like “species” in zoology; only instead of having within our reach the “types” of these species as in zoological collections, we are obliged to rest content with approximations thereto, for it is a very rare occurrence to meet with an individual representing the type of the somatological unit to which he belongs. Most frequently we have to do with subjects whose forms are altered by blendings and crossings, and in whom, setting aside two or three typical traits, we find only a confused mixture of characters presenting nothing striking. Ordinarily, the more peoples are civilised the more they are intermixed within certain territorial limits. Thus the number of “somatological units” is so much the greater when the “ethnic groups” are more civilised, and it is only among entirely primitive peoples that one may hope to find coincidence between the two terms. In reality, those peoples are almost undiscoverable who represent “somatological units” comparable to the “species” of zoology.
But, it may be asked, do you believe that your “somatological units” are comparable with “species”? Are they not simple “varieties” or “races”?
Without wishing to enter into a discussion of details, it seems to me that where the genus Homo is concerned, one can neither speak of the “species,” the “variety,” nor the “race” in the sense that is usually attributed to these words in zoology or in zootechnics.
In effect, in these two sciences, the terms “species” and “variety” are applied to wild animals living solely under the influence of nature; whilst the term “race” is given in a general way to the groups of domestic animals living under artificial conditions created by an alien will, that of man, for a well-defined object.
Let us see to which of these two categories man, considered as an animal, may be assimilated.
By this single fact, that even at the very bottom of the scale of civilisation man possesses articulate speech, fashions tools, and forms himself into rudimentary societies, he is emancipated from a great number of influences which Nature exerts over the wild animal; he lives, up to a certain point, in an artificial environment created by himself. On the other hand, precisely because these artificial conditions of life are not imposed upon him by a will existing outside himself, because his evolution is not directed by a “breeder” or a “domesticator,” man cannot be compared with domestic animals as regards the modifications of his corporeal structure.
The data relating to the formation of varieties, species, and races can therefore be applied to the morphological study of man only with certain reservations.
This being established, let us bear in mind that even the distinction between the species, the variety (geographical or otherwise), and the race is anything but clearly marked. Besides, this is a question that belongs to the domain of general biology, and it is no more settled in botany or in zoology than in anthropology. The celebrated botanist, Naegeli, has even proposed to suppress this distinction, and definitely show the identical nature of all these divisions by instituting his great and small species.[2]
The idea of “species” must rest on the knowledge of two orders of facts, the morphological resemblances of beings and the lineal transmission of their distinctive characters. Here, in fact, the formula of Cuvier is still in force to-day in science. “The species is the union of individuals descending one from the other or from common parents, and of those who resemble them as much as they resemble each other.”[3] (I have italicised the passage relating to descent.) It is necessary then that beings, in order to form a species, should be like each other, but it is obvious that this resemblance cannot be absolute, for there are not two plants or two animals in nature which do not differ from each other by some detail of structure; the likeness or unlikeness is then purely relative; it is bound to vary within certain limits.