It would be of course possible to dispute whether the word “science” should convey this quality of certitude, but to most people it certainly does at the present time. So far as the movements of comets and electric trams go, there is no doubt practically cock-sure science; and Comte and Herbert Spencer seem to me to have believed that cock-sure could be extended to every conceivable finite thing. The fact that Herbert Spencer called a certain doctrine Individualism reflects nothing on the non-individualizing quality of his primary assumptions and of his mental texture. He believed that individuality (heterogeneity) was and is an evolutionary product from an original homogeneity, begotten by folding and multiplying and dividing and twisting it, and still fundamentally IT. It seems to me that the general usage is entirely for the limitation of the word “science” to knowledge and the search after knowledge of a high degree of precision. And not simply the general usage; “Science is measurement,” Science is “organized commonsense,” proud in fact of its essential error, scornful of any metaphysical analysis of its terms. Now my contention is that we can arrange the fields of human thought and interest about the world of fact in a sort of scale. At one end the number of units is infinite and the methods exact, at the other we have the human subjects in which there is no exactitude. The science of society stands at the extreme end of the scale from the molecular sciences. In these latter there is an infinitude of units; in sociology, as Comte perceived, there is only one unit. It is true that Herbert Spencer, in order to get classification somehow, did, as Professor Durkheim has pointed out, separate human society into societies, and made believe they competed one with another and died and reproduced just like animals, and that economists following List have for the purposes of fiscal controversy discovered economic types; but this is a transparent device, and one is surprised to find thoughtful and reputable writers off their guard against such bad analogy. But indeed it is impossible to isolate complete communities of men, or to trace any but rude general resemblances between group and group. These alleged units have as much individuality as pieces of cloud; they come, they go, they fuse and separate. And we are forced to conclude that not only is the method of observation, experiment, and verification left far away down the scale, but that the method of classification under types, which has served so useful a purpose in the middle group of subjects, the subjects involving numerous but a finite number of units, has also to be abandoned in social science. We cannot put Humanity into a museum or dry it for examination; our one single still living specimen is all history, all anthropology, and the fluctuating world of men. There is no satisfactory means of dividing it, and nothing else in the real world with which to compare it.