The features which distinguish one ethno-geographic province from another are chiefly, according to Bastian, meteorological, and they permit, he claims, a much closer division of human groups than the general continental areas which give us an African, a European, and an American subspecies.
It is possible that more extended researches may enable ethnographers to map out, in this sense, the distribution of our species; but the secular alterations in meteorologic conditions, combined with the migratory habits of most early communities, must greatly interfere with a rigid application of these principles in ethnography.
The historic theory of "centres of civilisation" is allied to that of ethno-geographic provinces. The stock examples of such are familiar. The Babylonian plain, the valley of the Nile, in America the plateaus of Mexico and of Tiahuanuco are constantly quoted as such. The geographic advantages these situations offered—a fertile soil, protection from enemies, domesticable plants, and a moderate climate—are offered as reasons why an advanced culture rapidly developed in them, and from them extended over adjacent regions.
Without denying the advantages of such surroundings, the most recent researches in both hemispheres tend to reduce materially their influence. The cultures in question did not begin at one point and radiate from it, but arose simultaneously over wide areas, in different linguistic stocks, with slight connections; and only later, and secondarily, was it successfully concentrated by some one tribe—by the agency, it is now believed, of cognatic rather than geographic aids.
Assyriologists no longer believe that Sumerian culture originated in the delta of the Euphrates, and Egyptologists look for the sources of the civilization of the Nile Valley among the Libyans; while in the New World not one but seven stocks partook of the Aztec learning, and half a dozen contributed to that of the Incas. The prehistoric culture of Europe was not one of Carthaginians or Phoenicians, but was self-developed.
2. Slavery Defined[225]
In most branches of knowledge the phenomena the man of science has to deal with have their technical names, and, when using a scientific term, he need not have regard to the meaning this term conveys in ordinary language; he knows he will not be misunderstood by his fellow-scientists. For instance, the Germans call a whale Wallfisch, and the English speak of shellfish; but a zoölogist, using the word fish, need not fear that any competent person will think he means whales or shellfish.
In ethnology the state of things is quite different. There are a few scientific names bearing a definite meaning, such as the terms "animism" and "survival," happily introduced by Professor Tylor. But most phenomena belonging to our science have not yet been investigated, so it is no wonder that different writers (sometimes even the same writer on different pages) give different names to the same phenomenon, whereas, on the other hand, sometimes the same term (e.g., matriarchate) is applied to widely different phenomena. As for the subject we are about to treat of, we shall presently see that several writers have given a definition of slavery; but no one has taken the trouble to inquire whether his definition can be of any practical use in social science. Therefore, we shall try to give a good definition and justify it.
But we may not content ourselves with this; we must also pay attention to the meaning of the term "slavery" as commonly employed. There are two reasons for this. First, we must always rely upon the statements of ethnographers. If an ethnographer states that some savage tribe carries on slavery, without defining in what this "slavery" consists, we have to ask: What may our informant have meant? And as he is likely to have used the word in the sense generally attached to it, we have to inquire: What is the ordinary meaning of the term "slavery"?
The second reason is this. Several theoretical writers speak of slavery without defining what they mean by it; and we cannot avail ourselves of their remarks without knowing what meaning they attach to this term. And as they too may be supposed to have used it in the sense in which it is generally used, we have again to inquire: What is the meaning of the term "slavery" in ordinary language?