BEFORE we proceed with the systematic comparison of our twenty-one societies, which is the purpose of this book, we must meet certain possible objections a limine. The first and simplest argument against the procedure we propose may be stated thus: 'These societies have no common characteristic beyond the fact that all of them are "intelligible fields of study", and this characteristic is so vague and general that it can be turned to no practical account.'
The answer is that societies which are 'intelligible fields of study' are a genus within which our twenty-one representatives constitute one particular species. Societies of this species are commonly called civilizations, to distinguish them from primitive societies which are also 'intelligible fields of study' and which form another, in fact the other, species within this genus. Our twenty‐ one societies must, therefore, have one specific feature in common in the fact that they alone are in process of civilization.
Another difference between the two species at once suggests itself. The number of known civilizations is small. The number of known primitive societies is vastly greater. In 1915 three Western anthropologists, setting out to make a comparative study of primitive societies and confining themselves to those about which adequate information was available, registered about 650, most of them alive to-day. It is impossible to form any conception of the number of primitive societies which must have come into and passed out of existence since man first became human, perhaps 300,000 years ago, but it is evident that the numerical preponderance of primitive societies over civilizations is overwhelming.
Almost equally overwhelming is the preponderance of civilizations over primitive societies in their individual dimensions. The primitive societies, in their legions, are relatively short‐ lived, are restricted to relatively narrow geographical areas and embrace relatively small numbers of human beings. It is probable that if we could take a census of the membership of the five living civilizations up to date, during the small number of centuries through which they have yet lived, we should find that each of our Leviathans, singly, has embraced more human beings than could be mustered by all the primitive societies taken together since the emergence of the human race. However, we are studying not individuals but societies, and the significant fact for our purpose