INTRODUCTION TO SOCIOLOGY 805
pearance of the lower human types, by the development of the latter, or by their extinction and by the extinction of the higher simian varieties. If the observation of Agassiz remains in part true, that one cannot see the distinction between the intelligence of a small child and that of a young chimpanzee, we have seen, nevertheless, that, notably in the development of the centers of association, their brains are quite distinct and are differentiated at the departure from the uterine life. The development of "he chimpanzee is arrested early, while the child is cerebrally organ- ized by selection and heredity for a career incomparably longer. However, among men the intellectual capacity varies. Primitive peoples cannot count beyond 2, 3, or 5, then follows for them the infinite and unknown. For the superior varieties of the human species these limits are extended ; yet the law of limita- tion remains constant. Our potential psychical ability is limited, just as our muscular force. In his Systtme social et des lots qui le regissettt, as well as his Anthropomttrie, Quetelet has tried to extend the process of measurement of the exact sciences to intellectual phenomena. Contemporary experimental psychology would be unjust in not recognizing these efforts despite their imperfection natural to the epoch in which they were produced.
The tendency to intellectual uniformity is nevertheless con- tinually realized by the disappearance of the less intelligent societies and in each society by the continuous elimination of the less intelligent, or indeed by the development of inferior societies, classes, and individuals. This tendency toward reduc- tion of differences between intellectual attainments and between civilizations proves in itself that the variations of our intellect are limited. Differences exist, indeed, in relation to certain anatomical conditions of the brain and to correlative sociological conditions, but the resemblances between civilized and savage peoples are fundamental and constitute the rule to which progress only limits the exceptions.
Certain linguists have arrived at the conclusion that there is a determinate number of irreducible languages corresponding to isolated and primitive races. These languages also require a particular structure of the throat and vocal organs. The latter
