146 THE AMERICAN JOURNAL OF SOCIOLOGY
and at every point he has a chance of catching a suggestion of the meaning of brain structure and of mind. In the lower orders of brain the structure and meaning are writ large, and by working up from the simpler to the more complex types, and noting the modification of structure and function point by point, the student is finally able to understand the frightfully intricate human organ, or has the best chance of doing so. Similarly the biological sciences practice a rigid genetic and comparative method. They recognize life as a continuum, and they pay more attention to its simpler manifestations, perhaps, than to its higher, because the beginning of the whole process is most significant. They are there nearer to the source and secret of life itself.
But it is a somewhat singular fact that while the social sciences have been profoundly influenced by the theory of evolution as developed by the biologists, and have imitated the methods developed by the biological sciences in the study of plant and animal life, they have generally failed to connect their studies of society with the researches of anthropology and ethnology, that is, with those sciences which stand between biology and civilization. And yet the lessons which the sciences dealing with man in historical time have to learn from the life of the lower human races are even more important than those which they have learned from biology.
It is of course entirely proper for the student to limit himself even very narrowly to a special field in order to work it intensively, but the historian, for instance, who begins the study of human activity with Greece and Rome or even with Assyria and Egypt, cuts himself off as completely from the beginnings of his own subject as would the psychologist who neglected all study of child-psychology and of animal mind, or the biologist who attempted to understand bird or insect life without a knowledge of the stages of life lying below these. Indeed, when we consider that the human race is one, that human mind is everywhere much the same, and that human practices are everywhere of the same general pattern, it appears that the neglect of the biologist or psychologist to study types of life lower than those in which he is immediately interested could hardly be so serious as the neglect
