THE MECHANICS OF SOCIETY 245
none existed, continued to act in the same direction, which could now be none other than that of their modification and transformation into different and more efficient structures. Both the origination of structures out of the structureless con- dition and the modification of the type of structures already formed are dynamic phenomena. All nature is plastic and this incessant pressure of the social forces for the betterment of types of structure has resulted in an almost universal but exceed- ingly gradual change in these structures. The sociologist has before him the task of explaining the precise modus operandi of these changes. The fact to be contemplated is that while the functional effects of almost any social structure are greater than would be the effect of action without any structure, the effects of the later modified structures are greater than those of the earlier unmodified ones, and the effect of the progressive trans- formation of human institutions has upon the whole been that of vastly increasing their social efficiency. The same effect has attended the creation of new institutions, or the multiplication of social structures. How does this take place ?
We saw that feeling was the dynamic agent, and therefore it is here certainly that we must look for the initial impetus of all dynamic phenomena. We also saw that function (nutrition, reproduction, growth, multiplication, qualitative perfectionment) is essentially statical, and therefore it is useless to look in this direction. If, however, we examine the phenomena of function we shall see that they are all indirect in the sense of not follow- ing immediately upon the act that produces them as the effect of an efficient cause. The acts are not causa efficientes but only causa sine qua non. In unintelligent beings it is not to be sup- posed that the agents that perform the acts that produce func- tional effects have any conception of the nature of such effects. The animal does not eat in order to nourish its body, but to satisfy hunger, nor does it perform tin reproductive act in order to continue its race, but to gratify an instinct. In the human race, so far as man's animal nature is concerned, the case is scarcely different, and the most rational communities would forth-
