THE SCOPE OF SOCIOLOGY 327
which means of correlation have to be invented. Multiplicity of persons presents its own problems to the persons. They vary from the primitive problems of shepherd and farmer to the present reaction of the public opinion of the world upon French justice and British war.
Multiplicity of persons is, on the other hand, at the same time an enlargement of self. There was good science in the Levitical promise : "And ye shall chase your enemies .... and five of you shall chase a hundred, and a hundred of you shall put ten thousand to flight" (Lev. 26:8). Both for good and for evil, five men may have twenty times the resources of one, and one hundred may have not twenty, but one hundred times the resources of five. To be sure, the question arises: " But why does it not work in the same way with the hundred and the ten thousand as with the five and the hundred?" It does; the one group manifests the working of the same laws which operate in the other. But the dominant forces evidently differ in the two sides of the comparison. This simply serves to illustrate an ele- ment upon which stress is to be laid at every point in our analysis, namely : No single factor in association is sufficient to explain the general features of association. On the contrary, association is a function of the most complex variety of vari- ables that science has anywhere encountered. Our business is to detect as many of these variables and to learn as much about them as we can, qualitatively at all events ; and not to allow our theories of proportions to outrun our knowledge of qualities. Moreover, we may find the division of the facts frequently remarked in the effects of the physical environment duplicated in the case of the personal environment, namely : The multiplicity of persons has an effect, first, upon the bodily and mental structure of men ; and second, upon the thoughts, the actions, and the experiences of men. All the phenomena of sexual and social selection, in the physiological sense, would be evidence under the first head, and it is unnecessary to enlarge upon this phase of the facts. Multiplicity of persons is the sine qua non of that wide range of selection which promotes rapid and radical modification of individual type. The opposite condition that is, paucity of
